Decarbonizing Wastewater Treatment - WEFTEC 2023
everybody knows waste water is a challenge uh we don't treat enough of it right depending on which paper you read anywhere from 20 to 50% is what we treat in terms of global volumes so that means anywhere from 80 to 50% it remains untreated so or minimally treated right and this is our agricultural runoff this is our industrial discharge this is our sewage so we have a significant volume that we still have to address but given the percentage of waste water that we do treat eventally right with the existing infrastructure that we have requires a massive amount of energy if you're especially if we're talking about aerobic digestion uh highly skilled operators and a and a very significant infrastructure investment to treat the percentage of wastewaters that we do and the industrial sector sector right you have very highly concentrated waste and this becomes a pretty big challenge especially if you're a large producer in a small municipality and so if you if you read the latest and greatest right treating what we treat the way that we do it now generates more greenhouse gas emissions than the shipping industry this is a massive amount of emissions and there was a study that was published from Princeton University February of this year that showed uh measurements of 63 different utilities specifically their anerobic digestors across the United States and what they found comparing their data relative to measurements done by the EPA and ipcc that there is a significant underestimate uh relative to the emissions that our industry produces daily in fact about a factor of two and so we've got some sign significant strides that we need to make now most of these emissions are actually coming from leaky anerobic digestors so anerobic digestion is is often seen as a wonderful technology and it's the it's the industry standard for dealing with high strength waste Waters and you can do energy recovery right you process that high strength waste you generate some methane you can purify it for co-generation process or you can inject your natural gas it's a great solution but unless you've got a an airtight chamber you've got some significant emissions that were not previously accounted for so probably our Baseline in terms of what we are at in terms of industry is much higher than initially anticipated so we got some work to do so now how do we do it right um a majority of our waste water is captured about 63% is captured 20 to 50% is adequately treated before discharged if you look at the amount of consumption globally and per uh water usage this is this is a proxy for how much waste water we're discharging as well in terms of overall percentage so Municipal Water right we're extracting we're utilizing 10 to 12% of our Global Water demand industrial is closer to 20% and of course most of our consumption and runoff is associated with agricultural processes I'm going to focus on the industrial sector and this is where aquacycle plays a role uh it's a pretty big segment relative to uh water that we need to treat and it is some of the most challenging waste Waters out there uh very high strength High concentration so aquacycle what we do is a bioelectrochemical treatment technology it is energy recovery is possible although that's not really a part of our value proposition we can complement anerobic digestion processes but we work at a scale that's a little bit higher so our incoming concentrations are anywhere from 50,000 to 150,000 parts per million of biological oxygen demand so we so far the only technology on the market that can treat undiluted wastewaters from food and beverage processing so that means any given production process most of the waste water is generated from cleaning so let's say a bottling facility for example uh you you're going to be potentially manufacturing the syrup that goes into a can of soda 1 of that can is the syrup four fths is sparkling water if there's a bad batch of that syrup yeah you have a few thousand gallons of very concentrated waste water that goes down the drain that becomes a big challenge for municipality say you have expired product that's coming back and anything that's damaged or expired through the distribution system or in the bottling process manufacturer wants to recover the aluminum and the plastic they Crush all of that product the cans and the bottles they and they do that material recovery but all of that product now goes down the drain now these bods are extremely high and so most of municipalities count on a good amount of dilution in order to be able to deal with this stuff as it comes down the sewer however as bottlers are actually reducing their water consumpt that means less dilution factor that means a pretty big problem for the municipality and for the producer so that's why we look at these undiluted streams that's why we play in a space that's uh a little bit above where digestors are CU we can treat these very specific small volume High concentrate streams so the majority of the water that leaves the plant fairly high quality to enable reuse and to also enable a little bit more liability uh and uh uh open capacity for the municipality so when you compare our technology relative to activated Sledge conventional process for Iration anerobic digestion and this is not high rate anerobic digestion this is your conventional process and us the bio electrochemical treatment technology are bet there's a few things that we're addressing uh in the in the carbon cycle so number one if we go Apples to Apples comparison in terms of the amount of bod cood that we remove on a daily basis we produce a lot less biomass so this is a lot less wasted sludge that ultimately has to be collected trucked and otherwise managed and by managed typically that's sending to a landfill where it then breaks down into greenhous gases so minimizing the volumes uh is a big help right in that carbon cycle but majority of the Savings in terms of greenhouse gas emissions comes from saving energy so if we look at the amount of energy that is required for treatment again Apples to Apples comparison looking at an activated Sledge process requires a pretty significant energy demand estimations are anywhere from .5 1.2 kwatt hours per kilog Cod that's required from an ation technology to treat these concentrated streams now it can be as high as two right if if you don't have good good mixing Etc with anerobic digestion it's lower you cover a little bit of energy with our system we're actually two orders of magnitude lower in terms of energy consumption so you're looking at 02 to 04 Kow hours a day per kilog of cod that we treat can be in the same range of energy recovery but what we make is actually DC power there's no there's no biog gas that's generated out of our system there's no methane so as DC power if you wanted to convert that to useful energy right uh you'd have to do an a DC to AC conversion there's a lot of losses we try to avoid that but when we're on site we're either trying to power ourselves or forklift charging stations LED lighting for a Warehouse Etc so we don't have the loss associated with that conversion where we fit into the treatment cycle there a number of different places um so our bioelectric chemical treatment technology can sit and handle these really low volume High concentration streams in that case we want to remove as much bod cood as possible then we're discharging to a post treatment plant right so typically an irration technology then we can go off into a membrane uh system for reuse so it can be a part of a full Sol solution to enable the customer to reuse water outside now say a customer or a municipality already has anerobic digestion now we just talked about the fact that we're probably underestimating how well our digestors are working but you know say if we can keep them really working well keep all of the gas trapped energy recovery is a big deal right it's an important part of the in digestion process but you lose a lot of energy if you have to separate your solids and landfill them often total suspended solid loading that's allowed in anerobic digestion is quite low but we can take that up to 10,000 parts per million of total suspended solids on consistent concentration to our systems so if we're looking at higher volumes can utilize our system we break down total suspended solids heed to an anerobic digestor and actually increase biogas anywhere from 14 to 50% so we're excited about the possibility of being able to Plug and Play and complement existing Technologies but I'm going to focus on one particular application today and that's our work with Pepsi Cola in this case it's volume High concentration that bottling uh example that I talked to you about before so flow out of the facility anywhere from 100,000 to 150,000 gallons a day but only about 3% of that flow represented 60% of their suro so these are the bad batches this is the returned expired damaged product and so we've been operational on their site uh in California here for about 2 and 1/2 years over that period of time we've shown a net 30% reduction in their sewer bill cuz we're eliminating the SE charges and making sure everything is normalized without these major spikes of bad batch that might go down to the municipality and because we're treating anywhere from 1,600 lb to 3,000 lb a day C removal only 60 kwatt hours we're actually mitigating over 100 tons of greenhouse gas emissions every single month because the equivalent energy requirement at the activated Sledge plant would be closer to 2,500 KS so the mitigation story is what what uh enabled this relationship to become public um before we weren't actually able to talk to uh to the fact that we're working with even though we're saving the money and normalizing their sewer bill but because there is such a focus for environmental U social and governance goals scope one two three emissions within Enterprise clients and and consumer product goods companies this became uh an exciting topic for them to speak about as well as for us so I'll tell you how it works so we utilize the biochemical treatment technology and it is is very similar to a microbial fuel cell we got it to to work we utilize naturally existing bacteria already present Wastewater or sourced locally the environment that we're working in there's nothing that is genetically modified there's nothing that's grown in the lab we bring our containerized system to a customer site Source the material locally we mix it with the waste water that we're trying to treat and the bacteria start to form biofilms or fixed films inside each one of these reactors if you want to see what these reactors look like we're over in Booth 245 and we've got one over there so you can see what the inside with it and what the system physically looks like so the bacteria attach and they start using these surfaces as a way to breathe or way to respire and in that process of respiration the bacteria utilize that surface which is a conductive anode a way to dump electrons you capture those electrons we move them across a circuit we generate DC power faster we move away those electrons from the bacteria faster we're making them respire faster we're making them breathe when they're breathing really fast they eat really fast so the more electrical current that we draw right the faster we move electrons away from the bacteria faster the treatment rate so essentially we are electronically controlling microbial metabolism so stack these units together like Legos each one is about the size of a standard car battery we pack them into a shipping container we plug and play onto a customer site now hydraulically each each box it's not operating independently right we have 40 4 Z of these reactors that are operating in hydraulic series the number of reactors we have in series defines how much bod cood we can remove from the incoming waist stream and depending on on what it is that we're treating so with Pepsi we're removing um anywhere from 60 to 85% of whatever it is they're sending us and that accounts for 1,600 to 3,000 lb a day of total load now we're only processing a small volume right but very high concentration each 40t container can process about 10,000 gallons a day but if we have to go and address larger volumes we would take the stacks of reactors out side of the container and basically rack them up similar to how you would see a desalination plant you put it in the warehouse we've got lines of reactors that are consistently working so the other advantage of the tech is that it is pretty simple uh and because each one of these reactors is generating electricity it's a signal on performance and we have integrated sensors also so we we can know what's happening with flow with ph uh with with cood and B REM and all of that information is coming to us real time so we know the health and performance of each system in the field we can catch issues before they become real problems on site most of the time we can troubleshoot remotely without having to send an operator which means we don't need a full-time operator on site at the customer site reduces our cost and it really simplifies the process the things that break are the pumps so if any of you make really good reliable pumps I'd like to talk to you but uh we plug and play uh we like I said this this particular model has been going for 2 and 1/2 years with Pepsi very successfully uh within the bottling sector uh we we typically can show our customers a 20 to 60% saving against what they're doing 100% compliance to whatever permit they're operating under whether that's industrial discharge to sewer or npds to the environment and a 90% reduction in greenhouse gas emissions relative to anything on the market today today so we've been validating the technology across a lot of different applications over the last 7 years uh Brewing so we deal with the tuo we deal with a really high concentrate stuff and Distilling it's pot ale possibly some spent leaves as well uh in confection it's candy coating and some chocolate and in hydrocarbon remediation we can actually deal with aromatics and longchain hydrocarbons moving them down to below detection limits same process same approach and our longest running system is actually at a pig farm getting manure for the last 7 years and this is really our longevity study so over the last 7 years we have not actually had to replace a single component on the cortech replace pumps we've opened up the boxes to see how they're doing um but overall done some terrible things to these systems uh We've let them dry out over several months we've uh bleached them we've run a lot of different chemical cleaning products through them but because it's a bofilm system because it's fixed film it's extremely robust and when we bring back into a consistent operational environment we see recovery in 24 to 48 hours right back to the same levels in terms of bod and cod removal and energy recovery so we've also worked with the US Military and uh demonstrating how this technology can retrofit into Sanitation Solutions and Replacements to chemical toilets that ultimately is our mission sanitation for all is still in 2023 more people have a cell phone than a toilet and so our goal is to be able to take these same little black boxes retrofit them into different Footprints to apply to rural and urban sanitation situations so you have a you know technology that can work without an energy grid and without a sewer grid uh provided safe and reliable sanitation ultimately that is our goal so I'm more than happy to answer any questions we're based in uh Escondido California we've got offices in the Netherlands expanding into the European market and we're really excited for uh how this technology can apply and help decarbonize this water overall thanks where's the Pepsi Plant and and they give tours they do allow tours as long as they don't work for Coca-Cola um and uh it's located in Fresno California I imagine that um with you know sugar water you don't have to worry about debris too much but do you have other applications where you have to screen or actually we do have to worry about debris um so because of the crushing operation that's going on there you know they're collapsing these bottles and cans and so get labels you get caps you get all kinds of stuff that can lined up in our reactors and we have actually pulled plastic El on um but uh we do have a basket strainer as an initial straining process uh and then we have uh Y strainers with very mesh sizes in terms of moving contents between tanks and then into our system and to deal with the stuff that we don't catch we have mation pumps so we'll grind up soft matter before it feeds into our system and depending on um you know how soft it is and how much the loading is we might do uh a solid separation step either centrifugation or stff um we can handle 10,000 parts per million of TSS we've tested up to 35 we don't like it we can do it but we don't want that much so we do try to separate out and then refeed back into the system so we can translate that timately eny so question was how does the technology work okay um yeah what is in the Box is in the black box so it is an anerobic process and what the black black do what the Black Box does is it creates an environment that selects for uh organisms that have this capacity for electron transfer to Solid Surfaces so in an Anor robic process in digestion right your your Anor robic bugs are fixing CO2 to methane that's what they're really good at uh our bugs don't make methane and so what they naturally do in the environment is they were driving mineral Cycles so they live naturally in lagoons and sediments they're even in your guts Drive uh sulfur cycles and metal cycles and so what they'll do in the environment in sediments is where we're we bioprospect because they're going to live in a high diversity of different types of organisms as the minor population so when we when we're going out to find the material we're looking for really black dense mud that stinks like Rod necks that's where our bugs live and they're going to be at an interface where it's anerobic and aerobic environment so you're going to have minimal mixing a little bit of oxygen and then you're going to have an Anor robic interface we want a huge diversity of organisms coming into the box initially then we're creating a select of pressure so that only those bugs that have that electron transfer capacity stick around and they out compete the others it takes about 1 month to establish that biofilm and we're inducing different electrochemical parameters around the bugs to get them to solidify and stay in place to grow and be happy and then we then we uh change from a batch condition into continuous flow is another equilibrium that has to happen but it's a concert of organisms right doing hydrolysis fermentation ultimately fermentation byproduct into electricity anerobic but the completing reaction is on the cathode interface which is a natural gas diffusion electrode where we take the electrons across the circuit those react with the oxygen at that interface not in the bulk it's right on the surface and we generate hydrogen peroxide which helps to reduce boping at the surface and new molecular water leaves yeah so the oxygen show the this reactor scheme here again so the white wall on the reactor is a gas diffusion electrode so that means there's no forced air in the system but oxygen can permeate across that that white barrier it's uh it's open to air yeah so on either side of that box and we've got a gas diffusion electrode so that's the sidewall on each box so oxygen is going to diffuse naturally through that membrane structure and then the oxygen is going to react with the electrons coming across the circuit and the protons that are evolved from the oxidation reaction internally then that evolves new molecular water and H2O2 the H2O2 the peroxide reacts internally it doesn't stick around um but the new molecular water leaves and it's only a little bit come check out the box 8245 any other questions it's a a high pressure situation inside the box no it's low pressure 5 PSI primarily we're running gravity feed so the pumps that transfer waste water into our systems they're actually not shown here there's a lot of different feeder boxes that are um associated with each plane of reactors inside the container so the height of the feeder box relative to the plane of the reactors it's feeding is what defines the maximum flow rate for the system so that's gravity fed in we do have a transfer pump but it's like horsepower it's pretty tiny uh and then our mation pumps which help feed it into the supply tank so the Precision control on the back end of the the treatment train is a peristaltic so we can very precisely control the total flow rate but it's the height of that feeder box that is maximum flow through the container and that's gravity fed now if we don't not if we are not in a container we can flow a lot faster cuz we hit the seedling height right uh so in a warehouse situation we can flow a lot faster but it's still low pressure 5 PSI less reduction so question was bod reduction so we start on the high end right we're we're taking in 100,000 parts per million we're going to remove anywhere from 85 to 99% of that start the question was startup do we need to provide a charge uh no so what we're doing is uh how we are controlling the electrochemistry in the system is first off we just want them to form a biofoam so we're not stressing them out so it's basically open circuit but there's a minimum polarization between the anode and the cathode so a really big resistor uh and we're just we're just kind of mixing in the waste waterer and allowing them to settle on the surface then we step down the resistor and we start allowing more current to flow and that puts more stress on the biofoam and then over time right we're stressing them out to a point they can't keep so much energy growth we keep them in a fixed maintenance mode so we're not generating a lot of extra sludge that's how we minimize our our our waste activated or waste biomass and so but that that's the month process it's a very stepwise procedure build the biomass addess the biomass and then they do what we want them to do other questions all right right on time thanks [Applause] guys
2023-10-16 06:23
