Transcript [EN]: Wastewater Training, 2 of 3

good morning everybody uh welcome thanks for joining and welcome to the second round unit two of new epic's wastewater training uh with general liberty i'm drew youngs and i'll be moderating jim's training today so as uh same as last time for those of you maybe that weren't here just wanted to go over a couple housekeeping items excuse me i made a mistake make sure you guys are on the same page as me okay so just wanted to go over a couple housekeeping items so those of you that are calling in you're on mute and that's just to reduce the background noise if you want to communicate with me the moderator feel free to use the chat function it's at the top right of your screen or if you if you go to full screen and hover your mouse at the top um a drop down menu should come up and you can use the chat function feel free to ask questions uh to jim about the training at any time and what i'll do is i'll just kind of keep a log of those questions and you know ask jim when he takes a break so you don't have to wait until we prompt you for questions if something's on the tip of your tongue feel free to put a question out there and we'll address it when the time comes again just use the use your mouse and hover at the top of your screen to toggle in and out of full screen and that's how you can use those functions and again the webinar just like last time we're going to record this so you can access it at a later date if you have other colleagues that want to see it maybe if they missed this week and they want to catch up before next week we'll work to put both unit 1 which was last week as well as unit 2 online for you to review before our third unit which is in a couple weeks on your screen still getting through the speed bump so the technical gets difficulty so sorry about that everyone so i'll keep the intro brief today this was in the last presentation as well jim's been at new epic for a long time and he is an expert on water so we'll uh we'll let him do the training we'll leave it at that for now [Laughter] so again the training is broken into three units we've already covered one today's unit unit two we will go over a little bit on microbiology biological treatment fixed film systems and suspended growth systems and i'm going to go ahead and hand it off to jim thank you drew okay so last week we talked about primarily physical chemical type uh treatment that we do in the plant and we jumped over the biological process uh as a physical treatment in terms of removing what we call screenings uh debris of various sorts uh chunks of wood cans rags what have you large material that the biological process can't treat we also talked about removal of grit density organic material like sand and coffee grounds and egg shells that again bugs aren't going to eat so we want to take that out because and the process we also jumped forward to the end of the process when we talked about disinfection where we took care of the pathological bacteria that we fear are in the wastewater and need to deal with in order to maintain good healthy environment so this week we're going to talk about what our process is really about the main gist of wastewater treatment is a biological process we have a lot of organic matter that comes into the plant and we need a biological process to break that down largely done the majority of the organisms that do this work are just single-celled bacteria microscopic little guys that do a great amount of work in a fairly short amount of time and let's see if we've got uh this is where we are in the process kind of in the middle of the the plank the water standpoint and this is where we're going to do our work and we've got a number of different ways to treat this and what we have now is after our primary treatment last week we went through screening or grinding we went through grit removal and then we went through primary clarifiers where we removed several solids and portable solids took those out of the water basically what we have now is all of our solids of that type are gone we've removed some of our suspended solids but we do have the bulk of our all of our dissolved solids the bulk of the bod is in solution so you can't screen it out you can't filter it out it's going to be in the process and this is what we're attacking from a visual standpoint it looks like relatively clean water and for well up up through the 1960s a lot of facilities kind of stopped at this point they disinfect and then off it would go just be strictly primary treatment which meant that the amount of dissolved solids we had in the wastewater and right into the river well this is what our job is in terms of biological treatment we need to remove what we call cvod that's carbon-based biochemical oxygen organic matter we have to take care of non-settleable solids we went through our primary clarifiers soluble solids came out quite readily but the non-sellable solids are colloidal material very small particles that have no real mass to them they don't want to go up they don't want to go down they just stay in the water and make it look turbid we have to find some way of taking those out of the process we're actually going to use the organisms to do that for us and in our probability your plant now has to take care of the nutrients the nitrogen and phosphorous loading coming into the plant and reduce that down to pretty close to zero well this is all you got to do very simple process feed the bugs you remove the bugs and everybody's happy when i talk about bugs i'm talking about the bacteria the single-celled organs everyone's going to do this work for us again this is what they are the 95 of the organisms treating this wastewater are just single-celled bacteria and they're made up of carbohydrates and proteins and some organics and some other stuff and they reproduce by fishing literally just break into two so here's our process broken down for the simplest insurance we've got food that's the organic matter the waste water we've got the bacteria bacteria come from a variety of sources humans themselves provide a vast amount of them they come in from the soil much as we try our sewer systems are not all that tight so water and organisms leak in through broken pipes and crack joints so we have supplies from there too and we have to give them oxygen you know that they've got food they've got oxygen they're happy kids so they'll go through synthesis they make more buds we break it down what we're doing is we're taking the organic matter that comes into the plant and we're turning it into bacteria [Music] during that synthesis process they respirate and they're taking in oxygen the same way we do when they give off carbon dioxide co2 and they also generate a little bit of heat in the process so if you go through your plant during the wintertime you look at your biological reactors you're going to see a fair amount of vapor above those tanks because it's heating up from the activity that's going on yeah when they're respirating they get off co2 ammonia some other stuff as i mentioned they would be produced by fission they consume organic matter and at some point they just break into two they continue to do that and if you look at their reproduction cycles depending on the organism we're looking at it's very short matter of minutes up to hours or even days for some other ones but if you were to look at organisms over a 30 minute life cycle and you kept them fed and aerated in 12 hours that's what you end up with starting with one just by them doubling every 30 minutes that's why we have to remove them so we talked about uh microbiology for some degree yeah water pretty much water anywhere contains organisms two years ago i was trying to set up our microscope and we don't have a treatment plan but it had rained that morning so i just went out from the backyard got some water out of a puddle put it under the scope and there's all sorts of little critters running around in there they're all over the place all right the time that we find the waste water we've got rod shape we've got spirals we've got spherical this is basically what they made up 80 of them it's just water the other 20 percent dry matter and of that dry matter 90 percent is organ theoretically if you got your junior chemistry kid out and you uh went to work c58702n you got a bug i've never tried it really if you break them down they kind of lot of different things largely carbon oxygen nitrogen phosphorus is an important thing for them and they pick up some trace compounds treatment in that respect and that's what a single cell bacteria a little flashlit ribosomes stuff that keeps them going key thing about them is they have this capsule is their outer wall and on top of that they've got this sticky substance basically a polysaccharide a sugary substance very sticky and we're going to use that to help polish the water when we settle them off later on that's how we get rid of that suspended matter that's making the water look terrible so without getting too deeply into microbiology we look at two different types of organisms classes heterotrophic and autotrophic the ones that we deal with they differ in their nutrition requirements the heterotrophs use organic carbon as their energy source they're going to remove the cbod from our process i think whatever comes in and bring that down these got carbon they could be aerobic they could be anaerobic but the vast majority of them are what we call facilitated bacteria they prefer to have free dissolved oxygen in the water but if you don't have it they can look around for other sources of oxygen the autotrophs use inorganic carbon carbon dioxide their energy they also oxidize inorganic compounds and they're the ones that do nitrates and sulfates they'll do nitrification for us so if we next two weeks from now we talked about nitrification we're actually talking about autotrophic bacteria that are employed in that particular process so we want to keep them healthy we want them to perform the best they can in order to do that they have to have certain nutrients for every hundred pounds of carbon that we have to break down we should have five pounds of nitrogen and one pound of phosphorus in the wastewater if we don't have that proper ratio they're not going to function as well as they should it's somewhat ironic in that we're very concerned about removing nitrogen and phosphorus from our wastewater but we also have to make sure that we've got a certain amount in there to keep the process working properly we also need dissolved oxygen at least a half a milligram per liter of cutting generally runs considerably higher that's the minimum foot so microscope exam uh you guys got a chance to look at the microscope last week oh you had a microscope yeah i don't remember it mission meeting poster session oh no i thought you meant in the class it's an important part of process control you know we've got very large systems that don't change very quickly generally unless somebody nukes your plant and then you got to find out what happened but things change slowly so looking under the microscope to see who's around is a very important part of keeping track of what's happening in your plan and this chart that we've got over here is indicative of all the organisms you might come across in the process and by seeing who's there it tells you a lot about how your process is right helps identify certain uh organisms sometimes that helps differentiating particularly filamentous bacteria [Music] basically has to bump into its food source it's got that pseudo pod and kind of wraps around it and slowly digests them this is something you find very early in starting up a treatment this means young sludge doesn't take very long to develop these they're not very sophisticated we're getting the flagellus you can see his little tail that helps him swim around he's actually going to go looking for food this little club that you see up here on the top is kind of yellowish above the euplana that is a clump of untold number of single-celled bacteria all lumped together as flock park you can see the difference in size between this fellow and any one of these we talk about free swimming cilia these are silliest they have little hairs all around their body to help them swim when you look at them under the microscope they're little race cars just shooting across the field they're very quick and moving around and searching out their food source quite often you'll see them feeding around the outer edges of a flat particle you're doing this upper left picture here the stop ciliates ones that look like tulips that is what we really want to see when we look under a microscope that is indicative of a very well-run process things are very good this is a quote you might find single ones but also find them in colonies like this three swimming silliest up here that's what everybody's looking for this particular one this is satoria this is a a stock ciliate of a different variety and instead of having that open mouth stock ciliates have that open mouth with the cilia there they help throw the food down inside that tulip shape so they can digest it well this one has all these little spikes out there and there's a little organism goes by just sucks them in on the end of that spike and then pulls their guts out basically and that's kind of a horrible type of a thing as we're getting into these larger uh organizations with the fact that it goes through a kind of spiral somewhat like a football as a so we're water indicating when we see this type of organism in numbers under microscope is we're starting to get older sweat if you see its size and relationship to this clump of millions very old sludge that means we've got to start doing something we have to remove it old that's what he really looks like oh they become very popular all of a sudden i don't know why his t-shirts and stuff really he's a creepy little guy very old switch and we got some stuff like brussel worms high nitrates in your wastewater you get a lot of these into your system you walk out to a firefighter it looks like somebody killed the knox [Laughter] almost looks like there's a crazy spider in the middle of it all but these wiry type things the different types of foreigners we refer to as filamentous organisms there's a wide variety of these this is something we want to see in some number because you can see it here it helps hold flood particles together and when we finish our process what we want is we want large flat particles so we can settle it out by clarifier this helps kind of like a rebar to hold it all together you get too many then you have trouble settling out in your fire fire this is where it's a certain art form and being able to identify which ones arrive really troublesome you get this type of a deal it's like a plate of spaghetti you're never going to clean up your water probably you've got to find the reason for this particular filament correct it and get rid of it a lot of grew out there for a lot of different reasons slow dissolved oxygen high organic loading you get a particular one card you have to get a lot of grease you've got this particular it's kind of nasty it has a very distinctive structure so it's somewhat easy to recognize under the scope fungus fungi generally an indication of low ph conditions by looking under there we can learn a lot about how our process is running remember the fact that our plan is running on data that's five days old although it helps to look under this i know before you get that bad number out of there algae a common problem other ways of clarifiers well these organisms have referred to as three and faces look at it from the standpoint we're starting up a whole new process another way of looking at it there's law growth declining growth and what we call endogenous space a lot of growth is again we're starting a process so i've got very few bugs but i've got a lot of food so there's no competition for the food it's easy to find there's plenty of it so they just eat and reproduce like crazy and your population the dotted line goes up dramatically your food the solid line comes down quickly because they're just gobbling their stuff up like crazy in the declining growth stage now you've got to stop looking for the food you've got to compete for it so the growth rate slows down and our food processor is still doing dwindling here coming down finally get into the last phase what's called endogenous phase where there's very little food but we've got a lot of bugs so they basically self-cannibalize turn on themselves and go after their own carbon as an energy source that's what's happening exponential growth we've got a particular process and we'll show that the planning growth a little further down into the system as we've developed a lot of uh population we don't have so much food anymore and ultimately into the industries there are things that actually operate on this bridge the u.s filthy used to sell one that they called the animals or obviously look at what's happening in that nigerian food there's no food we've got bacteria we've got oxygen so the bacteria becomes the food for the other one the larger guys who have to swallow and they break it down into again this is you know a good place to run because you actually end up with less sludge in the long run than you do with a conventional process because they're just fueling themselves up the yellow circle that's about where you want your plant to be right about at that point there just enough food imagine we've got a lot of different ways of doing this process we break it down into two basic categories attached growth or fixed film represented by trickling filters and rotating biological container contactors then we have suspended group activated splash and all its iterations that's a trickling filter this is developed in the latter part of the 19th century in england came across the united states pretty soon afterwards this is a modern-day version of one we've got a large tank uh generally circular but not always and inside that we'll have a media and we're going to let the water trickle down through the media the proposed do their thing so there's a cross-sectional figure so we have a tank yes we've got a circular one in this part of the country there's not too many of them here in new england anymore pittsfield has them as uh trying to think of welfare they're generally built into the ground for temperature reasons well in the winter if they're exposed in the bottom of the tank we have what's called under drains it's a support system supporting the media and now you wanted to pass on through get a picture of that and then we have the media the media varies from rock about the size of your fist or a baseball up to plastic structures of various sorts and we have a distribution system this one shows two arms that rotate with nozzles along the length of the arm that spray the water out across the top area of the thing i could have four is generally driven by the water flow coming up through the shaft early days of uh under drains they were made out of vitreous clay now they're made out of fiberglass and plastic materials where you start eating this just need to support the structure and allow water to pass on through a picture here this is using the plastic film now the build originally was random filler would be rocks it'd be broken bricks slag material like that you can see in this particular picture and its purpose is to provide surface area for the organisms to live on more surface area the more bugs the more bugs the more water you can treat but if you think of it think of a tank full of rocks you've got a certain volume in that tank and you've got all these rocks that are wedged up against each other the volume of the rock is solid so there's no help in there you're losing some effectiveness you also have all these pinch points for stuff to collect and clog a lot of plants in an upgrade would switch their random fill to something like this these are plastic devices and just to provide surface area but if you look at them the actual plastic structures takes up very little volume very thin material but gives you a lot of space a lot of airflow there's also what we call structured films unlike hay bales like honeycomb just lay them in there long sheets of plastic but a lot of room inside there that's a lot of space and if you look at the difference between them this is showing the amount of area is what matters to us the amount of area per volume and how much void space [Music] media crushed stone the original version you get roughly 20 square feet per cubic foot of tank and your void space is 50 to 60 which is hard to believe look at it so i've got room for the year to pass through and the water pass through and i got some space slag's not much better we come down to the random plastic on the bottom here depending on the type that you choose you're doubling at a minimum up to four times the amount of area in a given volume and the void space is fantastic you don't have to worry so much about clogging that good air flow through everybody see there you don't go anaerobic destruction packing that may be all type of stuff again 30 to 60 square feet per cubic foot again great void space in there so if i need to upgrade my plant and all these plants that were built back in the 60s and 70s those towns are no longer the same size by and large they've grown considerably so they need to upgrade the plant well they can just take out the rock and put in this random plastic and they're at least doubling their capacity to treat just by doing that relatively low capital investment is our rotary distributor this particular unit has four arms and we have an orifice stretched out across that so we get a nice even distribution over the surface area of the top of the tank and it all flows on down these tanks can vary generally from four to eight feet deep there are some uh high rate ones that are about 40 feet tall not so much there are rectangular ones obviously in a rectangular one you don't have a sweep on to spread the year of so they've got basically a bunch of lime sprinklers out there to help spread the water around oh there's diagram here kind of what's going on we've got our water coming in trickles over the surface area works its way down through the media passes over the media organisms live on that surface this is why we want to have a lot of surface area they're going to consume the organics we have air is supplied here there's a natural draft by the water flowing through the media so we've got oxygen they've got their food they're happy little guys and our water should come out pretty well clean we're also going to get what we call schleppings because what happens is jump head here it's our rocker and we grow this slime the zoglio slime on the media and it gets thicker and thicker and thicker however at some point the organisms who originally attach themselves to that surface no longer get the food they no longer get the oxygen they go anaerobic and they die and the water flow as it comes by will then knock this stuff off the media call this fluffing if we were just they didn't come off then this thing just got thicker and thicker and just clogged the whole thing up now i said we have to remove the bugs this doesn't remove it this is removing it from the trickling filter but not from the process airflow the water's colder like in the summertime airflow is downwards in the winter time if you drive by a plant with trickling filters you'll just see this vapor cloud hovering over the top of the tank it tends to go upward a little warmer water so we should break these down into three basic types of strictly filters the standard rate that's my this is all i have we have high rate function much higher rate higher flow rate and we have what's called a roughing filler so again we look at these it's look at hydraulic loading and organic loading we only want to put so much water to this unit over the course of a day and it's based on the square footage of the tank itself the organic loading is based on the volume of the tank the cubicle but we want to stay within certain ranges they tend to have recirculation for some reasons that we'll see the sloping as we see here because it's such a low rate it's kind of intermittent so you may have to do things to control that you don't want to get too bad six to eight feet deep but it'll remove 80 to 85 percent of your vod it's good enough to get you through your permit so you know if you've got a small town it's not a very high tech operation works pretty well the bottom line here filter flies that's one of the issues with a trickling filter the particular little dat and that type of a fly the psychotic fly filter flies and they just hover around the tank again because of the low flow you're really not flushing out the eggs or anything they'll just repopulate problematic high rate filters much higher flow rate from an or a hydraulic standpoint we're always recirculating here the fluffing is continuous because of that high rate so we're always knocking material off the media a little less on the vod removed and a roughing filter a roughing filter is a particular unit where i've got a plant and i've had trickling filters for years but i have to upgrade and they're also putting other constraints on me like nitrogen removal or something else so a trickling filter is not the best method of dealing with it but i've got these units here i'm going to retain these because i'm going to run through my process at a very high rate of flow and i'm going to pick up about what's down here body removal about 50 of the body's going to come up now i can build an activated sludge plant which is the one with the most control after this and it doesn't have to be as large because i've already taken a big cut of my vodi that's what a roughing filter does it moves a certain amount of that vod so you can have your subsequent process could be that much smaller very common in a place like this if you go to pittsfield that's what they'll have again recirculation is there for we have a summerlike this past summer where flows are extremely low we don't want the filter to dry out we want to keep things moving so we're going to recirculate water just to keep everything in good shape it's also there if particularly if it's a standard rate filter i can crank up my recirculation rate to blow out some of those filter fly eggs take care of that issue and it can also be used to dilute incoming wastewater we tend to have a high vod situation coming in or whatever what's the strength of the wastewater coming in we need to basically blow the snot out of the down tank we have to do that these things going during low flow situations keep it all wetted talk about funding in a minute the little toxic waste and bringing some material back in our organisms back to the process you know we don't have to dry out have some was a really difficult time for everybody because it was so true but we talk about operational problems fall is a particularly tough time of year for tripling filters when all the leaves are dumping out and on where they're located you've got to make sure the top of these beds are clear excuse me from ponzi refers to just that you take a look at the top of your filter and you've got standing water what that means is your media below that is plugged for one reason or another and if no water is flowing through there then likely it's going to dry out it's going to go anaerobic it's going to smell and you're going to get calls from the neighbors deal with that crank up the research will flow in there try to flesh it out worst case scenario we'll just flood the entire filter let it soak try to break up the material that's clogging it and then drain it up that's generally a causing deodorant if you've got that kind of blockage filter flies real problems with low rate filters get some of your problems crank up the recirculation rate blow all the eggs out get rid of them keep things going yeah relatively simple operation in terms of process control not a whole lot to do throw the water in there see what the bugs do and you get what you get the other method of attached girls is rotating biological contact these are generally in smaller facilities they're very common in what we refer to as package plants if you've got an industrial park or a shopping mall has to treat their own material these things are very common the nursing home got in the cave that runs a couple they're indoors just part of the countries are always what we've got is california they just ride it in we've got a tank and we've got a sham 25 feet long and on that shaft we've got a series of plastic discs that provides the surface and these discs slowly rotate through that bat of wastewater of 35 percent of those discs are immersed in the wastewater they turn very slowly couple rpm so the bugs go down they get their food they come up they get their air they get out and they get their moves they come up they get their air they're happy again they just build that slime on these discs same as we saw in the trickling filter on this though we really don't have a mechanism for that stuff coming up it just has to fall out naturally we've no recirculator to do anything a simple process a 25 foot shaft about 12 foot diameter probably has a hundred thousand square foot of surface area on it you get a lot of surface area it works very well but again very low tech you kind of it was yes you don't control the population the way you do with an activated sliding process generally chain or direct drive there are some that are actually air driven bubble air into the tank down at wallingford connecticut you can see these extended portions on this unit here those are what's called ear cups the air gets caught inside those cups and helps rotate the drum and also augments the dissolved oxygen in the tank itself to make sure we've got an adequate amount this is the media this one was not operating at the time but it's the same process there's your disk and we slowly grow that slime on there water passes by the bugs do their thing at some point the aerobic portion just dies off and the fluffings come out we're going to pick those out in another clarifier this one this one was actually operating it's hard to tell if you were to see it in better lighting you see there's some reddish areas inside this line that's hanging on the disc that indicates that they were nitrifying at that yeah typical time setup we've got our preliminary treatment our primary clarifier and then we go through our rbcs typically they'll have banks of four to run in series and then the sloughings from these this is true of the tripling filter too is going to go to a secondary clarifier much like what we saw in the primaries we have to remove those organisms at this point they're covered even in other parts of the country here we need to keep them covered or indoors because of freezing the real issue uh heavy rains would wash it off if it were just out there in the rain the sunlight's not good for algae and it's also not good for the disc surface it's not the plastics so when these things are running normally we'll have a uniform shaggy brown to gray biomass i mean it's shaggy it's just hanging off this stuff should be a few bare spots but as you go through from one unit to the next if you've got a four stage unit that third and fourth may be kind of sparse as the vod is pretty much exhausted at that point if it's black and smelly then we've overloaded the unit you can also see somewhere you've got a white biomass on there that's indicative of a couple of filamentous organisms over here that thrive on sulfur compounds for nitrifying we're going to see a reddish brown biomass 80 to 95 vod removal do very well you can get your nitrogen down fairly well they say downsize quite well you generally don't see them in plants greater than 3 million gallons a day enter the charlton rest area on the turnpike right up behind there is their treatment plant they're all running off rbc's are we doing we have any questions uh yeah so getting back to uh been a few slides but the water bears a fan favorite are they dangerous organisms to happen it's not dangerous no i mean if you're single cell bacteria it's probably not good to come on no but it's an indication that we have very old sludge we tend not to get into that range just something that we look for not particularly dangerous no more dangerous than anybody else and so maybe maybe the asker was referring i'm assuming here but like what if they were in drinking water for instance is that something the drinking water is the concern yeah you've got problems when you're drinking water okay so you wouldn't that would i would not uh recommend it no okay that should not be happening but they're not actually pathogenic they're not a parasite it's just a particular organism that's out there and for folks in the phone if i'm not doing the best job capturing your question feel free to shoot me a follow up and we can keep that uh conversation going so another one uh jim you were kind of speaking on this recently um so the question is why do we need nitrogen and phosphorus and water aren't those harmful why do we need it in water yes well again we need a certain amount for the organisms to be healthy you gotta take your vitamins in the morning they do too they will not perform their best if they don't have that required amount of nitrogen or phosphorus it just is part of their metabolism they need that in there and that's you know we would talk about uh particularly the phosphorus removal in a couple of weeks how you do it can be detrimental to the process if you don't do it right because it's this chemical treatment you can do some in up in your primary and say okay we'll take that phosphate clock out of the primary clarifier but if you take out too much then your biological process suffers because you don't have enough phosphorus for the bugs to be healthy so it's just it's a requirement of their metabolism any questions in the room so she had a question about the um you talked about trickle filters one of the maintenance aspects if flows are not meeting the low end is to just force flow and keep them wet i was wondering what the opposite end of the spectrum is so if if you're exceeding your max flow like do you just does it just accept the flow and you maintain it after the fact or do you divert the flow or well this is an issue whether it's a trickling filter or any other uh means of biological process there are extremes in flow you'd be amazed at how quickly your flow can triple and quadruple within an hour or two during a heavy rainstorm you think of the area of drainage that you're covering with all your collection systems all that water comes in so it's probably more logical to think of it on the activated sludge process as an activated sledge you've got bugs swimming around in tanks full of water okay now when that flow goes from three million gallons a day rate up to 15 million gallons a day rate we think the velocity of water is in those tanks and how fast can a bug swim upstream so if you can't do something then you're going to wash out your bugs same thing with a trickling filter you're going to flush everything out of that filter if you can't do something there are situations when you can bypass your biological process in order to save the facility you'll disinfect at the end and when you think of it right well we went from 3 million to 15 million but the difference wasn't all the same stuff that was you were getting at 3 million you deluded it five times so from the biological standpoint you take the hit to save the plant otherwise you lose your plant for a month or so trying to get back in shape so there are things written into your permit to allow you to do that under extreme circumstances and then that outflow if it didn't meet some sort of standard that wouldn't be a violation because it's written into that in other words if the water wasn't treated and you lost the bug but you also expelled that effluent like is that a violation of some sort uh i can't comment on that i'm talking somebody is state level okay so it depends any uh investigators out there i'm sure we do cool thanks i'm gonna hug all the time i think we're all set with questions for now that's it all right so this is probably a good point to break before we jump into the activated sludge because once we get into that we're gonna roll right on through so all right folks on the line uh five ten eight minutes let's do an eight minute break and we'll be back at uh 9 58. thanks sure we will all right everybody welcome back we're going to get to activated sludge i'll go back for a second to the question about the nitrogen and phosphorus being required there are facilities that depending on the nature of their incoming wastewater actually have to supplement this material in order to do it uh if you have oh i think your computer is healthy paper mills are notoriously nitrogen deficient in their wastewater so if you've got a paper millet town that contributes to the facility in our probability you have to add nitrogen by some meat aqua ammonia urea something like that when we were shutting down our process in new hampshire it was an industrial facility so we're shutting down various production areas over a period of several months but still running wastewater and we were shutting down the process that provided us with a lot of our phosphorus we actually had to argue some understanding of how well the regulators understand the real process had to argue with the state and epa to allow us to store phosphorus acid now they will get into the whole hazardous waste thing in order to keep our bugs working until we should actually shut the place down had to have that in order to be able to do it but anyways we're going to talk about activated sludge process this is the premier process again trickling filters and rbcs do a very good job of cbod removal they can remove the organic matter very well when it comes to nitrogen and phosphorus particularly phosphorus you kind of at the whim of the face activated sludge is where you have the ultimate control you decide who's around what they do and by manipulating them you can get them to do some fantastic work so indicate an aeromix biological treatment process where we're going to use these organisms to do our workforce they're going to remove carbon-based material and they're going to you know probability deal with nitrogen and phosphorus force to a certain degree so that's our very simplified process diagram if i can't get this arrow off the page there we go so our input that's the material coming from our primary clarifiers primary treatment effluent we have what we call a biological reactor probably will hear the term aeration tank quite commonly if you try to go to a treatment facility for some technical so we call them biological reactors the difference that we have here our rbcs and our trickling filters the year was free we really didn't have to spend any money it was just available it was in the atmosphere and they got it here we actually have to provide that because this biological reactor is a big large tank probably 20 feet deep we've got to get air all the way to the bottom of these tanks you can't do that just by letting the air float around on top so that's going to be a big part of it we're going to go into our secondary clarifier you have to remove the bugs we do that with the other units too the difference here is you see we actually have a return from that clarifier slides that we take out and we send it back into the process you don't have that with the other systems your recirculation on a trickling filter doesn't really do that it's just recirculating water here we're sending organisms back in and by controlling that and again we are going to have to waste them otherwise it'll get too populated so we've got biological reactors designed for some type of flow and we'll see some variations of how we can operate these we have to have an aeration source mechanical mixes it could be blowers we're going to have clarifiers again to separate the waste water from the solids and then we're going to take these cells we have to have a method for getting that back into the system we also have to have means for wasting from the system so there's another flow diagram coming in a couple of reactors we've got three clarifiers here kind of the general flow of things so our biological reactors are called aeration tanks our tanks where we may have different uh conditions set up see here we generally we're going to be aerobic but we talk about our nutrient removal we can get into anoxic zones or anaerobic zones to facilitate that process anoxic being essentially oxygen free no free oxygen we may have oxygen in the form of nitrates we have clarifiers you're familiar with those from last week's uh the difference from front to the back in terms of clarifiers your primary clarifiers will be a bit smaller than your secondaries your secondaries are almost always circular there's a new term for you mixed liquor mix liquor is the term we use for what we have once we take our incoming primary effort going into our biological process and it's mixed with the sludge that we pulled out of our firefighter that recycle flow we're mixing the organisms in there so it's a mixture of sludge basically and your incoming raw wastewater suspended solids we know what that is stop floating around in water we put the two together we have a term we call mixed liquor suspended solids mlss this indicates the amount of solids that are in our reactor at any point in time it's a number that we look at on a regular basis we also have mixed liquor volatile suspended solids or mlvss remember our organisms of the dry matter ninety percent of it is organic well that's what we're looking at here multiple suspended solids indicates the living portion of those mixed liquor solids mixed flicker solids could be dead bottles they could be little bits of who knows what just debris but this indicates the living portion that's who's doing the work so we have to look at that in addition to our mixed layer what we do is we'll run a filtration test we filter out the suspended solids we can calculate that amount then we'll take that filter pad and put it in a muscle furnace at 550 degrees fahrenheit burn off all the organs by subtracting we know who's out there and who's doing the job for us we've got return activated slides or what we call raz it has a suspended solids component this is a concentrated version we have say 2500 milligrams per liter mixed liquid solids in the reactor our clarifier may have 5 5500 we're concentrating solids at the bottom of that tank for a couple of reasons we want to have a lower flow in terms of volume to send back and also it helps us when we go into solid handling okay sending hungry organisms back into the process to do the job for us and of course we have a waste stream and this solids component it's essentially the same as our ras because it's coming off the same point this particular term solas retention time or mean cell retention time is a process control number it indicates the average time the solids stay in the system by controlling this we determine what we're going to have in our population and what they're going to do so this is what a biological reactor looks like on an activated sludge process big tank full of water tons of buds again we look at back to our organisms based on time that mcrt or srt how long we keep a organism in the system again is the relative number of those organisms based on time so it's got our basically amoebas and some flagellates down here and as we keep stuffing the system longer we can grow more and more and higher life forms we get up into uh soxcillius up in rhoda versus nematodes and we want to know where we want to be on that scale of time this chart you'll find this in pretty much everybody's lab as an indication they have this next to their microscope based on what they see as a predominance of organisms it tells you how well your clarify is going to be performed and ideally you want a fair number of stock ciliates free swimmers some flagellates maybe a couple of rotifers not much in the way of amoebas but as we start to see an increase you know a shift in that population distribution it tells us what's happening so older sludge we have what's called pin flock on our clarifier not quite as clean as we'd like younger stuff stragglers you've got some other issues with it this is the ideal population breakdown and remembering that that's just these guys only make up five percent of the organisms doing the work okay we got a whole lot of different variations of activated sludge i don't know what's going on and it's really thin slices of the same cake this is what they call conventional process or fund flow sometimes called a folded reactor our input comes in here and we've got these long narrow channels that are working through not a lot of information so yeah just comes in and works as a plug as it moves through tag a bug you know you kind of watch it move its way through air is provided by some means all the way across we see here is as we come in remember that uh exponential growth phase of the organisms well there's a lot of food coming in here not a lot of bugs you know we've got some return sludge flow coming back in that's it so they go crazy you've got a very high oxygen demand here because they've got all this food and there's not many bugs that reproduce like crazy your population increases as we move through the reactor as we get over here the bod is essentially gone so if we just have an even distribution of air at the final end of the reactor here we've got a lot of excess oxygen which is wasting money there we've got a lot of problems with not much food so we're actually approaching that endogenous stage back there we're looking for something to eat watch that whole life cycle you know exponential here declining growth as we go through the middle up towards approaching expo endogenous growth on the far end of the reactor identified by a high length width ratio again narrow channels not a lot of intermixing make sure you've got plenty of do up to the front talk about you in a second you get a fairly high velocity because of the nature of that construction again your total suspended solids and your volatiles will increase as you go by works very well less susceptible as long as you keep that do up won't have any trouble with filament disability filamentous bulking is the term that we use we have predominance of filamentous organisms in the wastewater and our clarifiers just won't settle properly we can't clean that water up and low dissolved oxygen is one of the causes of some particular organisms that thrive in that condition i see you give them the conditions they thrive in they'll take over so you're going to avoid that we avoid low d.o all possible options until it's time to go the other direction so our application domestic industrial has two of all of these 85-95 vod removal is simple be done in no time at all really aeration type doesn't matter diffuser mechanical rsrt 5 to 15 days now if i'm only concerned with getting my bod down below 30 or 15 or whatever the number is three to five days is more than that you do the job very very quickly if i don't pay attention what's going on or if i have some problem with my solids handling and i start moving up into the 15 days that's where i have to be careful because we're going to start to get into that nitrification process by accident and that can wreak havoc if you're not doing it on purpose aeration time four to twelve hours hopefully done that's all it takes your mixed liquor solids 1500 to 3000 milligrams per liter we will vary this during the year in the summertime when our waste water is coming in at about 70 75 degrees it's warmer the bucks are more rapid we don't need as many bugs to do the job but as we approach october and the temperatures are starting to drop for every 10 degrees celsius drop in temperature on your input influence that pretty much goes from in uh august down to february you're going to half the activity of the organism so if i'm going into wintertime and i'm afraid i'm going to half the activity i need more bugs to get the job done so we'll tend to back off on our wasting and build up that population to get through the winter months then come march we get them out there because they're going to stop going crazy we have recycle streams varies for various reasons and here's a new term we haven't even mentioned yet f to m that stands for food to microorganism ratio and this is the typical range in conventional 0.2.4 pounds of bod per day per pound of volatile suspended solids we don't want too much or too little food for the number of bugs that we've got in there that are actually alive and working for us so that's actually a control point for us we may look at this mixed liquor number but again it really comes down to the volatile component and here's one other thing i talked to operators a lot and ask them what are they doing here and there for numbers and stuff a lot of them don't really pay much attention to those follicles this is an easy test you know it's a nice filtration test can be done quite simply blah blah the mlvss you know now requires you to go to the muscle furnace and go through that whole process and all that a good operation is going to track the ratio of volatiles to fixed liquor solids typically that should be [Music] 55 to 85 depending on how you process runs that particular plant was always in the low eighty percent frame oddly enough one of the reasons to look at this again just like looking under the microscope which is about as common as it should be if you're not paying attention and something's starting to happen to your process and your volatile number is starting to go down if you're just looking at mixed liquor solids you may never see that until you know somebody comes back with a vod number that says 28 that's supposed to be 15. it helps watch what's going on you want to make sure that this you know this thing in that ratio at a constant level tells you you've got a good healthy population that runs in your facility should be looked at this particular uh method here complete mix now i've got a fairly large tank and i'm going to distribute my incoming wastewater completely throughout the tank so that if i sample any location it's exactly like any other location in that tank just totally mix it up very quickly oh length of width ratio big tank instead of the narrow channels we saw before low velocity through the reactor and it'll accept wide swings in your material a lot better it can't be prone to filamentous bulking problems largely depending on the type of aeration you have those corners can be dead spots uh this probably have some issues my process ran somewhere but again 85 to 95 vod removal piece of cake five to 15 days same stuff not much variation here really stretching out the f down a little bit to 0.6 but all of that typical range for these systems this particular contact stabilization this is used in facilities that have real problems with eye and eye inflow and infiltration when the rain comes you just got a huge jump in your water flow the idea being i've got two reactors i've got a contact reactor my material is going to come in here and i've got my recycle stream coming in and i'm going to have about a half an hour to an hour's retention time in there and in this reactor the bugs are going to add absorb the food to their bodies they're not going to break it down they're just going to pick it up i'm going to run them into the clarifier settle them out and then set them to a re-aeration reactor for three to six hours that's where they actually break down the food stabilize and also repulsively quite a bit we've got a much higher population in here than we do in this state the reason that this works in the high flow conditions i've got a relatively small amount of solids here that high flow rate i won't overload my clarifier and have a washer everybody's pretty much safely back here got our resin there we've got to wrap it up the absorption followed by the stabilization that's typically used where you've got eye and eye problems which presumably you're working on correcting of course if you're nitrifying you have high solubles again it'll do the job after an hour in the contact tank three to six hours reiteration different populations in each day i'll still do the job and if the engineering firm was nice enough and thoughtful enough and if your budget was high enough if you had it unfortunately you folks out in computers you can't see this but if i looked at bring it down simply this goes back to a plug flow facility where we come in here and we come out there we'll give you a valving so that i could actually send this around and come in here actually you'd better come down right here switched my valve during the rainstorm i'd come in here this would be my contact tank just one short chamber and then my raz would come back here and this would all be re-aeration by changing your valves you could change from blood flow into a contact stabilization mode and try to save the flame step feed step feed is a combination of complete mix and plug flow you've got to completely mix that up but by redistributing your feeds all the way around you've got something very close to a complete mix and what you've got in this is you've got a very steady oxygen supply all the way through the reactor unlike with the plug flow we had a very high demand up front very little out the back just evens things out keeps you a nice steady uh oxygen demand all the way through again you look at the numbers they'll all do pretty much the same type of a job for you now extended aeration extended aeration is the process that actually works and relies on that endogenous phase of the organisms and it says extended air it's not kidding around instead of retention times of 5 to 15 days we're talking 20 to 30 days these are very common in seasonal towns beach towns ski towns that sort of thing we got a big population for a while and then everybody goes away the uh and the thing is different here you look at everything else looks kind of the same 85 95 percent body removal srt is longer definitely your aeration time is longer but the real key that indicates to us is extended air it's very low food ratio well below the bottom point two that we have in the other systems so again a lot of bugs not so much food they go endogenous they get less sludge they eat themselves up which is types of plants again light very light loading decent amount of sludge per pound and generally it's characterized by this type of a process what we refer to as an oxidation ditch it's just a big oval a lot of things running around the circle we've got some aerators here that move the water and also aerate it very common uh one i'm most familiar with up in north conway they've got two ditches up there beautiful plant people want to go see a nice plant right here at the bottom of route 16 you should come into town that's very common uh sbrs are also very common in those type of communities because of the way they're set up a sequence batch reactor you can see it's relatively small footprint compared to your typical wastewater plant the reason for that is everything happens in one tank they generally do not have primary treatment so we don't have those clarifiers you're still going to have preliminary trees and our clarifier and our reactor on the same tank and we work through discrete cycles to do what we got to do yeah when the high rains come it's good to have some equalization tankage up front to accept some of that flow so that we're not pushed to the limit they're generally built in multiples of two while one is reacting or settling the other is taking water in and you've been adapted quite well to biological nutrients but a bunch of these up in vermont all the ski towns obviously p10 they have uh sbr they size down very well you've got some condo associations they have nice little units that just chug away all day long a 500 gallon unit takes care of the wastewater from the condos could be rectangular common walls so we got to fill so we're going to pump water in then we're going to aerate for some amount of time when that time has been met so we're going to kill the air and now the tank becomes a clarifier we let all the solid stuff to the bottom basically a computerized version of fill and draw that developed in the 19th century at the end of the assembling time we decant off the clean water and we also pull out some portion of the sludge we leave some behind that acts as our return sludge but never left there's a decaying unit so that'll just slowly draw water until it gets down to a certain level around the bottom still yellow circle that's an aeration disc down there and if all is going well you've got idle time before it has to take it again there's some issues in earlier designs where they didn't have sufficient time some repeating while they're trying to detain it they work very well basically just chug along without too much of an issue 85-95 percent vary your uh ranges i know what you're doing and you can see from 0.05 to 0.3 pounds for from the middle vss kind of works the range from conventional down into extended air if necessary latest version well next to the latest i guess a membrane bioreactor these have been around for 15 years or more now i guess what we've got is we've got our reactor as we have the conventional systems it's operated in a slightly different fashion and instead of a clarifier we're going to pull our waste water through membrane filtration extremely tight filtration so here's your mix liquor there it is after it's gone through the filter the thing that is very different from your conventional system is you're going to run a mixed liquor solids of about eleven thousand to fifteen thousand that is six step that's one and a half percent solvent so what you've got is you've got a smaller reactor because you're going to have a higher mixed liquor in there and you don't need a clarifier you've got membrane filtration it also lessens your disinfection requirements because not much is getting through those membranes it's very expensive you don't find too many municipal plants with it gillette stadium they treat their own water and they run it all through membranes rent the village down there they use this nantucket surfside plant as mvrs get more and more common again they're great for smaller who call the package place the shop a technical school or whatever it is up here in voxpro everyone wanted that for their wastewater and the last but not necessarily the greatest iteration of the process again these are for situations moving bad bioreactors you have to upgrade your plan we've talked and you've exceeded that 80 or whatever it is they say you've got to upgrade to treat more well most plants were built down by the river at a point in time and you may have some way in and you may not well these are this is for places that have no place to go and since you have no land for more reactors or clarifiers what you do is you combine a fixed film process with a suspended growth process by throwing in some sort of media into your tanks now you've got growth on the media you've got the mixed liquor swimming around too so you can process more for a given tankage than you normally could but there's an issue when it comes to the wet weather situation and the heavy rains you recall the hooksett incident i remember probably still floating up there uh actually it happened uh first when we heard of the rock and connecticut i think it was might have been quest right i think they had the pink fuzzy balls that they had in theirs on a heavy rain all of this water wants to move it goes up some sort of retention system to keep these things in the tank well with enough flow and force the retention system failed and everybody escaped had a big jailbreak and they all jumped into long island sound or wherever then we had books in new hampshire who uh sometime later had the same situation eight million little discs i don't know only six million of the eight billion they had in the system broke free it came all the way down the merrimack river by on violence probably in morocco by now and uh america new york a few months later had the same kind of an issue so epa kind of backed off for a little bit and said we've got to come up with some better basically keeping these guys in apparently they have because they're still doing it again it's one way to get more processing out of a given volume it's the enzyme pharmaceutical of framingham they treat their water before they discharge the mwra and they use an mvbr for their processing combining both processes together it's the most treatment out of a given volume good stuff there's also it's out there so again here we have control over the process are we going to nitrify well we want to have a certain mcrt are we not going to do 95 we're going to do that we can look at various things typically we'll look at pretty much all of them and what we see make decisions again your f damn ratio if i want to control by my f to m ratio again i should be within certain parameters for this thing to work well what can i control can i control the food what comes in the front door comes in the front door we've got no control over we just have to react to what we've given i can control the mass by how much i waste more i waste the less mass i back off on wasting i'm going to have more minutes i mean sell residence time long are the bugs in the system well this is controlled by how much you waste got so many in there and i lessen the time that they're in the system by wasting more i take the war up or if i want to build that time up then i don't weigh so much so i come down to wasting sludge age it's another term somewhat some of that but different again controlled by how much is in the system it all comes down to this last item no matter which term i want to go by it comes down to how much i'm going to waste in the end so you know i can say well i'm going to maintain a certain mean cell residence time that's great to do it by wasting it all comes down to this and that's where you know we talk about issues with the problem if you have trouble with your solids handling and you can't waste well then you get into trouble we control what's happening and what they're going to do so again we have a different type of a system from the fixed film and that we have to supply oxygen so we need to get that oxygen to the buds we need to run typically between two and four milligrams per liter is generally the target range we look for you can run down towards one but you don't want to take a chance on generating some filamentous bacteria what you see in this picture is mechanical aeration it's a big mix master thrown into the middle of your tank this particular part of the process is the most expensive thing that we do spend huge amounts of money on electricity to aerate these organisms okay one to four ideally two to four and hopefully we've got even very good control over that now different methods of doing got a surface aerator here that's mechanical mixing the two pictures on the left are what we refer to as diffused aeration various types of systems out there provided mechanical surface aerators you go out to airmass you must mask their treatment plant they have surface aerators gathered into their reactors basically just an air uh axial flow pump sucks water in from below and then just sprays it out into the air picks up oxygen quite readily in the winter time these things can ice up and be problematic what they look like this picture on the right is the way they have it out hammers they're tethered inside a tank and there are some that are bridge mounted actually out there on a structure churning up the waters this is increasingly disappearing from processes for a couple of reasons one thing part of the process here in addition to removing the bod is we need to remove those suspended cells a colloidal stuff that's just hanging around so the bugs will do that it'll stick to that sugary substance on their bodies and we want to form these nice large flock particles that we see under the microscope see that later because the larger the floc particle the more mass the more mass the better it sounds but if i'm going to form a nice cloth particle then i'm going to take it here and run it through my ninja rocket point out of the expression and i just turn it up the other thing is if you think of it these tanks are rectangular so this is centered somewhat in the center of the tank how well is my aeration in those corners point distance from that mechanical mixer and if i have low dose there then you know no part of your destinations and some of those other local york elements could thrive and give me troubles the other thing if you walk out here there's always vapor in the air with these things so now i'm ingesting that stuff plus you walk out onto that bridge in the middle of february but have your cleats on because it's pretty darn slippery out there not a great thing that's what those uh aerators look like they sit inside that well and they're literally feeding the air into that water and you control you control it by the speed of the mixer itself or you can raise the lower the water level for the emergence of the blade we talked about oxidation discs this is the type that they have there it's a horizontal rotor and they do actually control it by raising and lowering the water out of the ditch as to how much those little fingers pound the air into the water now we go to diffuse there just a better choice this is what you look like not a lot of turbulence nice ease and even coverage of oxygen into the corners everywhere nice and uniform no low d.o areas works very well two purposes to this keep everything in suspension that's part of the process and also to aerate it pretty good job but again now i have to pump air down to the bottom of the 25 foot tank 25 feet of water plus the diffuser back pressure so i'm running 20 25 psi back pressure on that okay system is the uh upper unit the white pipe with the uh little disc there that's a nice fine bubble diffuser and this metal one down below is a coarse bubble diffuser this argument is the widget better it's a ceramic type this is like the stone you might have in your aquarium millions of millions of blue air bubbles going out there agitated different types aluminum silica membrane types basically a rubber type of a membrane that when the air pressure is behind it opens up very tiny holes in the membrane that pass up through but it takes a lot of and they have to be cleaned on a regular basis and repaired stuff you can see the depth of that tank how do we get the air down there today most plants are using things like positive displacement flowers a roots type blower or you can use a centrifugal blower the difference being a those first two words there positive displacement that means something's going someplace don't close a valve unless you want a bad day centrifugal blower is much like a centrifugal pump you can shut that down for a while bands will just spin it won't really cause much of an issue there's a big pd blower these root types of flooring that silver unit on the far end of the pressure relief just in case by some means the valves get shut over and apart rupturing your eardrums very tight this way you can't get a piece of paper between those two lobes is that location here comes in gets pumped up and pushed out ideally because electricity is so expensive particularly in this part of the country and we're using so much of it you'll have a control loop in there you'll have a dissolved oxygen meter in the tank and you'll have a control loop set up so let's say i want to control it at two milligrams per liter and this will sense what's going on the tank and it either speeds up the blowers or slows them down so you don't put in any more energy than you need to but you always get what you do need big motors upper blackstone where i do most of my training has three 800 horsepower blowers i don't want to paint that electric the centrifugal blower yeah this one's a little more forgiving and that actually open and close the inlet veins to control the airflow for these all these states are driven before pd blows we're talking a lot of air upwards of 50 000 cfm per unit 25 to 30 psi so pressure concerns when you deal with these things these are the latest and the greatest so far this is a turbo blower this thing is operating at 28 000 rpm you walk into a room with those roots blowers and they have the earplugs that you end up like me everyone here these things are absolutely amazing the reason that they they've rented about 40 percent of the horsepower of a conventional unit because they have no bearings i was going to provide very similar setup up in franklin new hampshire and honestly three blowers in there you can't tell which one's running except by the operating lights you can hear air rushing through the pipes but quiet as can be saves a lot of money oh this here needs to be uh why is this in here you got the filter system you don't want to be fully dirty particularly if you've got diffusers you'll plug them up and just get some then or dry barrier or an electrostatic precipitator various ways of cleaning up the year before we pump it down the bottom of the tank air flow measurement what we have in here is the corpus plate measuring flow an orifice plate is a steel plate that sits inside the pipe and it's got a diameter of a hole inside it that's considerably smaller than the diameter of the pipe at which it's sitting and by measuring the pressure drop across that plate and knowing the characteristics of that particular orifice you can actually calculate the airflow the differential pressure unit up on top of it takes that out sends the information to a controller they can regulate how much ears go to any tank at any point in time another method of doing it thermal mass air flow meter a lot less pressure drop again ideally this is your system a sensor geometer that sits inside your tank you have multiples in there there's probably three of them in each of the tanks up the blackstone and they feed back into a controller and that'll tell the blower to ramp up or ramp down so at any point in time at night time when your flow's way down you don't have much demand no sense blowing a lot of air in there and wasting electricity some facilities will use high purity oxygen instead of just regular air air is 21 oxygen and i would top it about 90 percent plus in a high purity oxygen plant deoriolus is high purity oxygen a lint treatment place high purioxy polio they run high purity oxygen theoretically you can have a smaller reactor because you've got so much more oxygen there and they tend to be enclosed again we're pumping all this oxygen in we want to recycle as much as possible we've got special mixers in there that help take the air from the head space and pump it back down so we can get as much of that oxygen and then it vents based on the amount of co2 in the system and adds new stuff in there it's done again theoretically you get smaller reactors that's fine it also seems to be in locations where you're very concerned over odors that's a treatment plant your reactors really shouldn't smell badly but they have a particular odor to them dear islands right out there on the harbor you've got to drive through winthrop which is not exactly the dumpy part of town and they want to make sure everybody's happy over there so that's all it's close lens is just up the road from them too we can truck in our liquid liquid oxygen actually holyoke used to generate their own now they truck theirs in gear island uses cryogenic system they generate their own high purity oxygen lint is used in pressure swing absorption to generate theirs [Music] we've got small reactor re-exercise but there's downsides to capital investment very complicated system to operate you've got safety concerns with high oxygen content areas okay first one so i don't know if you recall the picture we had coming out about primary firefighters relatively clean looking water this is what comes out of your reactor difference being that population of organisms it comes in looking like you know slightly dirty water to look more like chocolate milk you're talking 2500 to 3 000 milligrams per liter of solids so now we have to take that and make it nice clean looking water ideally it should look like drinking water it generally does so once again we're going to go through clarifiers or settlers or sedimentation tanks whatever you want to call them show somebody taking a sludge reading at the edge of the tank well again what we want to promote through all of this process and when you look at mixed liquor in your tank you should be able to identify this this is our flight nice strong flock particle very clear supernatant around it that's what we want to see that's why mechanical aeration is not exactly ideal chop that up it doesn't take much to break this apart minimize that turbulence make it nice so this is what we want not the sheared flock that's been broken apart it's not going to settle well we're going to have some turbidity issues i'm going to have some problems with our suspended solids okay we're coming out of our reactor down into a clarifier charlie just gravity flow secondary clarifier generally is a circular tank there are some places that run rectangulars not my favorite again 10 to 16 foot straight wall depth uh and on the the flows of the plant anywhere from 40 feet up to 120 160. same principle we're gonna feed into the center of this we're gonna have a big baffle this big circular wall this interior portion is called the feed well some units will have little agitators in there they'll call flocculators just keep the flock moving around bump into each other so you can form larger particles no high speed mixing solids are going to drop to the floor shouldn't be much affordable material but you'll have some foam and stuff it has to be dealt with there's a lot of variations in design developed over the years on this one you can see an interior launder here right in the forefront of the picture i'll explain the reason for that in a little bit so the difference between this and what we had up front in our primaries the fact that uh the primary we're going for settleable solids this is material that'll drop to the bottom of the tank and acquiescent conditions now we're talking about clumps of bacteria even when they form a nice spark particle still not that dense of material so we will have a larger clarifier in the back than what is the primary if you've got an 80-footer up at the primary you probably got 120 for your secondary we need more time for this material to settle it's uh solid as it was up front the other thing that we're going to do here is we're going to maintain a sludge blanket a layer of solids at the bottom of the tank two reasons for that is material comes down and keeps settling it compresses that and concentrates it so i've got mixed liquor of 2800 i'm probably running 5500 to 6000 on my sludge at the bottom of the tank so my pump to send return material back to the reactor is smaller because it's concentrated and my pumping out to my waist is smaller also but whatever comes out of this material out of here has to go to solids in and if i'm going anywhere basically i've got to have at least 20 solids so i got to get rid of all that water so i can get rid of a good portion of it here so much the better so there's concerns that there are density currents here based on temperatures and some people think the moving of the rake mechanisms generate some currents and again we're talking lock up bacteria so it doesn't take much to keep them suspended as quiet so there's all sorts of methods out there to prevent things from happening let's go back here again you look at this you follow the arrows the thought is that the baffle will push it downwards it scoots across the blanket and comes right up along the wall so it really is not there for the standard detention time that you would calculate it never is but it's very close so shorter time it isn't here the less time for things to settle so i'm going to carry material over when this comes out so the stamford baffles actually the crosby battle dr crosby uh came up with this design but he was working at stanford so incorporated that title put this sloped addition along the wall so that material came across the bottom of the tank came up the wall it would hit this have to return back towards the center before it could head towards the effort where trying to keep it in that much longer so the solids would actually drop out there's another variation secondary baffle this one's fairly high upper black stone is installed there so it sits over the rake mechanism it's probably not even going to put off the floor so it's going to come out of the feed well in the center by the moon is going to hit this baffle have to go over or under it again just another means of holding it in the tank that much longer close to its theoretical detention time the primary clarifier is an hour and a half to two and a half hours is generally adequate on secondaries you're talking two to three that much more time for this stuff to settle up because it's so light again the internal laundry instead of having it out of the outer periphery of the tank yeah the material runs across and hits the wall and comes up well now it's got to turn around and come back about a third of the distance towards the center before it hits that effort just another way to hold stuff in love we've got a scumbag this is something that i can almost promise you you'll find no matter what plant you go to and they clarify they're going to have a hose spraying water there out of the business that's because of some of the fault stuff now we also differ somewhat in how we remove the sludge from this tank from what we would have had on our priority primaries uh generally this is plowed down into the sump as you see here and then drawn away with a pump cypher systems draft tubes recovery whatever term you want to use it's very common with secondary clarifiers and we're dealing with a relatively light material so instead of plowing this down into a sump a rate mechanism the blades instead of all being oriented in the same direction now form a v and the apex of a v is a pipe that comes down and all these pipes go up into a box that's isolated from the water of the quackfire so as this slowly plows around it's pushing material towards these pipes and if we get see the pipes on the left-hand side inside that box arrangement of the brake mechanism here we go inside that box you see there's an opening from that pipe this opening is below the operating level of the clarifier itself so now i've got a hydraulic gradient and the water wants to flow downhill so as the water flows it easily picks up the solids off the bottom carries it with it up into this box and it's a pipe that takes this off to begin with later on one thing that's kind of good about this is that you've got a nice even pull of smudge across the floor as opposed to the plowing mechanism towards south where you may not have an even distribution you're going to pile it up as we're going to see in a minute a lot of things have come into play a mixed liquid concentration these clarifiers on the front end we're not concerned about a solid floating secondary we are we're only good for so many pounds per day per square foot so if we ran our mix liquor up to a real high number we're not going to settle out properly certainly flows a big factor affects your detention time and current your return switch flow can affect things by how deep you let that sludge blanket go unless you pull it down surface area if you're clarified over whichever one is in there and how simple is your sludge that filament this one you've got some issues and there are parameters design parameters not something that an operator would calculate on the course of a day aware loading rate we'll talk about we're loading rates on our primaries of 10 to 40 000 gallons per day per foot here it's ten to twenty thousand that's the maximum half the rate sorry surface overflow rate surface loading rate it's 800 to 1200 gallons per day per square foot on a prime rate now we're down to six to eight hundred just because of the nature of terrible settlement and here we do have to be concerned with solid floating 12 to 30 tons per day per square foot recommended area well mixed wiper is running way too high for some reason not gonna settle out uh i experienced this when i took over my planting used to run ridiculous mixed love and quicker numbers we couldn't settle it for love or money way too high that's a concern on this one uh take a look at that picture that looked good to you that's why i don't recommend rectangulars on the secondary wellington connecticut this is about six years ago and i was i was just staring at that thing the operator qmo says oh yeah there's no problem with that i'm good that would mike firefighter go back home and call it six of the day terrible so yeah we'll carry a sludge blanket and we need to keep track of where this thing is so for measurements on this and a lot of them were done manually with this big plastic tube called the sludge judge sections and you crank as many as you need together so you can reach the bus clear plastic tube and you go out to a certain location out on the bridge but people do it in various places as long as everybody does it in the same spot the same way then it's no big deal that's when somebody's doing it in a different place and it confuses things you drop it down slowly reaches the bottom of the tank at the bottom of it's a little wall chip when you're going down it allows the water to come into the tube and you pull it up that ball checks it you pull it up and you actually have a core sample of your clarifiers you can see where the sludge is the transition between the thickened sludge and the clear supernatant all that gives you a good idea for what's going on important uh tooltips there are devices out there that can ultrasonic devices that can sense the level of the blanket i've never worked with one i don't know how accurate they are or what they'll tell you but i like the sledgehammer so all sorts of here's a test that is done on a regular basis to see how well your clarifier is doing it's called sludge volume index this particular uh last cylinder is called a mallory settlement and what you do is you take a sample of your mixed liquor and location right at the end of your reactor as it's going to the clarifier and then you pour one liter so well this incoming one liter and two liter units the accelerometer has graduated zero to a thousand no matter which one you've got fill this up to a thousand with your mix flicker and then you let it sit for a half an hour take a look and you see what the settled sludge is after that half hour it also gives you an indication again look at this this uh hopefully is not settled yet but that supernatant is far from desirable i see how that looks at a clear break i settled solids here and clear supernatant nothing floating on the top and you do a calculation a subtle sludge volume 30 minutes times 1000 milliliters per liter divided by your mixed liquor suspended solids concentration you get a number theoretically 80 to 150 is where you want to be if it's below 80 you're settling too fast and you're going to leave some material behind if it's above 150 theoretically you're not settling well and you're going to have a problem it's a sludge blanket this is a this is typical of the type of a profile of your slice blanket that you might see in a clarifier that plows it down to a sun not necessarily one that has drafters it's going to kind of collect that and that's not bad gotta go and everything's moving towards the self as it should be this particular situation this actually occurred to me it took me a day or so to figure out what was going on for some reason the was not plowing down to the sun now we don't want to have too high a sludge blanket the reason being that there's no more oxygen or very little oxygen left here there's still a little bit of food there's still a lot of bugs so they're going to consume whatever's left once the oxygen is depleted they're going to go after other sources of oxygen that's where the faculty and bacteria if you have nitrates in there and you're nitrifying or something else they're going to go after that and break it down or you could just go septic and generate some methane gas or hydrogen sulfide and all of these gas bubbles will accumulate and finally have enough force to pop that sludge blanket up and focus on the surface you clarify clarifier just ruined your whole morning you don't want that to happen it's what happened to me and typically as your sludge blanket rises one of your controls is you increase your return sledge flow pull it out of the tank so you find out what's really going on it's the first move you make well as i did that i increased the flow but again the flow is going to be right here by this incoming pipe pulling material away apparently the increase in flow just exacerbated the problem and that it prevents stuff from coming down i just was rattling through here material just kept staying on the outer periphery of the race and just get these big blobs of stuff come floating to the surface and drive us crazy i only kind of figured out what might be going on and i'm way back on my return sledge flow within 12 hours all the material moved back down where it should be i was able to pull it out of there oh your secondary clarifier pretty nice looking water here nice and clean it should look like drinking water ready to go to disinfection some stuff that we really see um this is all the piping and uh pumps or you're returning sludge flows maybe galleys underneath the ground you don't get to see if you're just doing a normal walk around on how to remove that stuff backwards this is a low mass actually as well connecticut yeah the rash flow typically uh it's very commonly said at about 50 uh some philosophies will say okay we're going to keep it at a certain flow rate and we'll leave it there no matter what happens and some will tie it to your incoming flow your incoming flow goes up mostly you're going to get more stuff you'll also increase your rats accordingly but figure out a scheme that works best for you and let it go a return activated sludge much thicker than what we saw coming out of the reactor and again probably five thousand six thousand milligrams per liter is pretty typical of the concentration at this point the bulk of it going back into the reactors some of it being wasted that is your control of the wasting system questions on the activated sludge um yeah so could you speak a little more on how the gum baffle works this gun baffle scum baffle is just a plastic strip that will run around i can drive here but i won't help that it sits just outside your effluent and it probably goes 12 inches 10 12 inches below the surface of the water so anything that floats is going to hit that baffle and can't pass through to the airport wear itself that makes sense it's like a physical barrier it's a wall for the floating cap so it just can't get by that you'd have to have a heck of a deep scum layer to get past and underneath that that it uh yeah i had a question that might be um off phase here but regarding just the uh sheer energy demand of some of these uh plants is there ever a case of localized energy production whether it's capitalizing on hydro or solar or something more traditional or biological we are seeing a lot of facilities have taken up whatever available free land they have and put in solar arrays i think upper blackstone's probably got four acres solar array pittsfield's got a pretty good sized one out there the other thing that's being employed is some facilities that do anaerobic digestion are taking the methane gas from that process and using that to supplement the energy requirements either for heating the digester or running some equipment that sort of stuff all those examples are supplements some kind of things they're so they're not totally producing their own demand no okay not that i know of uh and you do find uh there's a number of wealthies that do have wind turbines set up got a big one or two out there on deer island now any questions in the room can you go back to the secondary clarifier slide i think which one the this just the that one so the water comes in in the middle of the tank yep and then it's there's a retention time and the flood can see just the the baffle just protruding above the water level right here yeah that's the feed well it's going to come in hit that and go downwards and then it falls into that trough in the middle right and then does it get pumped to the next to the outer ring or how does it is that what that was there's a pipe there are drain pipes in the bottom of this truck see that it'll go to a distribution box and then off to disinfection so what's that out the outer ring this outer ring here yeah that's a baffle there's a scrub baffle on both sides of this laundry what what the outer ring of water is what water i guess is that what's sold water also okay so that the same water is over this does not go all the way to the floor okay the water passes underneath here again the idea here being okay water that shoots across the bottom comes off the outer wall okay i'll have to turn around and go backwards i got it i got it that's one of the methods that they use to try to keep it in there that much longer that internal flander rather than whether it's on the outside yeah okay so that trot the middle trough actually doesn't go down to the bottom right okay no that's all right okay all right boom i can go back in time the room systems very common in rural areas hard to find one there's probably two of them in massachusetts you go north of massachusetts they'll be all over the place very low tech it's dates back to early days a.d for that matter it's pretty much letting mother nature do its job this is actually in rangeley maine the large tank here at the bottom is storm water retention then you've got two cells here operating the uh the wastewater treatment and goes way back actually they use it to grow fish eat tilapia not anymore [Laughter] general categories of stabilization font raw treatment with no prior treatment and oxidation funds have some primary treatment but they're predominantly stabilization funds that you'll find out in the rural areas and here's a scheme of a two cell pond got a flow meter we've got a bar screen we still want to take out the big chunk and then we just went to the pond they typically have uh 30 days detention time per cell you might have two you might have three thing about it is uh it's very low tech it's your biological reactor it's also your clarifier go from here overflows into the next one some are aerated some are shallow enough you don't have to they work pretty well for a number of years the issue with these things is that together a rural community small town low flows it's probably overseen by some sewer board a majority of whom don't even know where the lagoon is get elected to something and they ignore the fact that this has been used as the clarifier for the past 15 years now a pond that used to be eight feet deep there's only four feet deep and they can't get the treatment that they're looking for so then you have to come in and get all of those solids out of those tests is that a class on lagoon treatment uh many years ago that's when i was at hampshire and they adjusted this is fears mental bloom yep went to the mcdonald's no no it's right there at the offering we went to the parking lot took a french fry through it over the fence from the venus it's right there they just cleaned that out they had divers in there for a month cleaning out one of the cells they're lined right so there's no infiltration what they could be can guarantee they are this part of the country i'll bet you they are but yeah if they got a picture of the uh one of the divers standing at the inlet port of the center of the first cell and the water no longer came up to a speed stuff just comes out and just drops right there just moves it over time and just in fact the boom the way it probably goes an operator overseeing four plants in any given area we could have an aerobic pond it's only two to three feet deep you don't need any aeration because at that depth sunlight penetrates all the way to the bottom grow algae algae suck up co2 and give off oxygen bacteria suck up oxygen give off co2 it's a wonderful relationship anaerobic ponds are deep so jesus the sunlight can't penetrate to the bottom so whatever cells to the bottom becomes anaerobic and that breaks down on the anaerobic conditions then there's facultative kind of in between as far as depth if you're over the anaerobic at the bottom facultative in between pretty decent job i don't know what's happening but they do take some maintenance here we got uh stuff called duckweed that generates uh around the edges and all that prevents uh promotes insect growth has to be dealt with the levees we've got a bunch of muskrats and that sort of stuff not careful the banks will give way and then all of your water goes down into the stream which is not very desirable and uh yeah since they are very low tech you have not much control they can be kind of smelly but since they're out of the middle of nowhere doesn't seem to be much of an issue for anybody you can do it no i can't that must be the end of it all right is what about uh just jump in here um speaking of critters um like waterfowl they ever have a problem with not only that being there but the waste they might add to the system you can go to pretty much any plant and if you look at the clarifiers or some of the other channels that might be carrying water and you'll find uh monofilament being strung in a zigzag fashion around trying to keep the ducks and the seagulls out of them but invariably they get in there they always do it's not the the only real concern is when they're swimming around your chlorine contact chamber because that's not where you want them to go pooping you gotta do a bacterial test after that and that could be a problem but yeah they they always manage to get their way through other than that you may get a snake or a turtle now and then step and turtle is a real problem with lagoons any questions in here uh any any last minute questions you guys want to shoot through chat we'll give it another couple minutes and a friendly reminder i want to make an effort to put unit 1 and unit 2 online for you all uh they're listening before unit three and just as a reminder uh not gonna be able to do it next week so the next training will be february 1st which is two weeks from today and we'll have uh i'll go ahead someone from wastewater will reach out to this uh let's serve about uh you know when those when those go up online so i don't see any questions coming in feel free to reach out to myself or jim uh with questions that you think of after the fact and we'll work to get back to you or address it in the next training so thanks for joining today and see you all in two weeks have a good one thank you thank you