 Hi everyone and welcome to this institution of chemical engineers water special interest group and international water association masterclass, which is a panel discussion today. Just briefly that I can be as a professional membership organization for chemical biochemical and process engineers with a membership of around 40,000 members in about 100 countries, and the water special interest group is one of about 20 special interest which is run by a committee of volunteers and aims to share knowledge and share experience in water and wastewater treatment. My name is Amanda Lake and I've got the pleasure of being your moderator today. So I'm a member of the institution of chemical engineers water special interest group and also of the international water association and and their sub subgroup on greenhouse gas emissions. In addition to my day job, which is as a process engineer with Jacobs based here in Edinburgh in Scotland. I'm really passionate about supporting climate action in the water sector and and do feel that we've got an ethical obligation to do this to our profession and to our children and to future generations. And so where we're here today at our event called climate action now. And this is a fourth event in the masterclass series on process emissions which we've held over the past five months. It was really to coincide with the release of the international water associations book quantification and modeling a fugitive greenhouse gases from gas emissions from the urban from urban water systems. And really happy here to have two of the editors of that book Lou and Jose on the panel today. It's a really great open access textbook on process emissions and really the first of its kind published by Iowa. And it's contributed it's been contributed to by some of the leading researchers and practitioners in who working on process emissions. I had the pleasure of contributing just a very small amount to one of the chapters and and when I read the rest of the book I realized that, you know, such valuable knowledge that we really needed to get information out there and was fortunate that Lou and Jose were happy to come together and support this organizing this masterclass series to really talk about the theory and the practice and opportunities and challenges and that's really why we're here today. You'll find all of the we've had three previous masterclasses and general one which gives an overview of the topic in the book. We have a deep dive on nitrous oxide and one on methane and then to complement the kind of the great technical coverage in the book we've really tried to make the masterclasses full of on the ground practice in in utilities and practitioners who are actually taking action. And today we we we go back to the topic of nitrous oxide and we've got a really great panel, who I'll ask to introduce themselves shortly. But yeah, it's really great to have these groups share and initially I'll ask them to share a little bit about themselves and the work that they're doing. And perhaps where they're dialing in from today, because we really do have a global, a global panel of experts, and then we'll go back and briefly talk through some questions that we would like to discuss today. But actually, the opportunity is there for everyone on the call to raise their own questions so please, please do this in the in the questions box which you should see on the go to webinar panel. And just briefly on housekeeping, everyone will be all the attendee microphones will be muted, we will have a one and one and a half hour discussion today so we'll talk through those questions and hopefully it will be really interesting engaging discussion. Please raise your questions in the questions box, and I would also just remind everyone that the session is being recorded and it will be available to everyone online after the event. So with that, I think I'd like to go to each of the panelists and just ask them to spend a minute or two introducing themselves, where they're dialing in from and what their link is with working on nitrous oxide. So I think I will start with Lou, if that's okay. Thanks, Lou. Hello, everyone. Thanks for the very nice introduction and also you give a very good overview about the overall the masterclass and also the book. So my name is a little year. I'm currently dating from Brisbane, Australia. So it's eight o'clock in my time. I'm associate professor at the University of Queensland. So Amanda mentioned that I'm one of the editors of the book. So my research focused on the future greenhouse gas emissions from the other water system. So I start to work on the nitrous oxide emission back to 2010. So I've been working with all the major, a lot of major Australian water utilities to quantify to model and also mitigate nitrous oxide emissions from the treatment plan here. So I'm also doing fundamental studies, look at fundamentally how microorganisms produce nitrous oxide on the different conditions and how we can use molecular tools and also modeling tools to understand these emissions. So hopefully that in today's session, I can share more about what we have done in Australia and also some of my perspectives in about the future, how we can better quantify and mitigate nitrous oxide emissions. Thanks. Thanks, Lou. And I'll go to our other co-editor today. Jose, thanks. Thanks Amanda. My name is Jose Poro, founder and CEO of Cobalt Water Global. And at Cobalt Water Global, we're actually focusing on mitigating nitrous oxide from wastewater treatment facilities. And we're doing that using AI and machine learning. And AI is something that really started working with in 2013. And N2O is actually something that, as a group, the IWA task group started discussing back in 2009 and in 2010, we formally launched the task group and really ran the task group alongside the research on N2O and helping to coordinate and provide direction for the research, which over the course of a decade or a little more, we were able to gain a lot of knowledge on the pathways and the influencing factors. And ultimately, the book is what synthesizes a lot of this research. So we're pleased to be able to be launching this and be having this webinar series, which Amanda, thanks to you, taking the leadership and initiative to kick it off. We've been able to do an excellent job in giving a highlight to the book and preview to what's in there. So I think it's an excellent way to get the word out. So thanks to your efforts on that. Thanks, Jose. We can go back down under and I'll ask David, would you mind introducing yourself? Hi, everyone. My name is David Duhass. As you heard, I'm also in Brisbane. I've been here for approximately 25 years in Australia. I started in South Africa as you'll probably pick up from my accent. And my background is in biological processes and my specialization is in actually biological and nutrient removal activated search systems. And I work for a company called GHD in Brisbane. We're a worldwide consultancy, somewhat similar to Jacobs, and we do, you know, engineering across a whole range of disciplines. Now, my specialization, as I say, is in nutrient removal systems, and that's really what sparked my interest in nitrous oxide. I think my first encounter with it was working alongside Dr. James Barnard, who many of you would know as one of the fathers of biological pee removal systems. And he commented that nitrous oxide is produced as a trace as a side stream in denitrification systems, but not sufficient to cause any hilarity because we know it is, of course, laughing gas. So that kind of sparked my interest in the 90s, but really in the early 2000s, I began digging further to try and understand how much of this is produced and what the relativities are compared to energy systems and the greenhouse gas emissions from energy and electricity use. And that led me to work with the University of Queensland and hence the link with Liu Ye because she's also in Brisbane. Through others, of course, at the, what used to be the Advanced Wastewater Management Center in Brisbane, Paul Lant and Jo Keller and many others. So from that sparked a whole bunch of interest papers published largely with colleagues around life cycle assessment, urban water systems, greenhouse gas production. In those and more recently, I've had an interest in the emission factors that we assume for accounting purposes because from an engineering point of view we kind of always get to that low level of fundamental detail. We need to have some broad indication of what the emissions are from using emission factors. And so that's led to a more recent paper published internationally reviewing the IPCC emission factors and comparing them against others around the world such as the system we have in Australia. So I guess that's my interest and look forward to the webinar to sort of hear the broader perspectives internationally as well. Thanks, David. And now we end up in Denmark, which is a nice place to end with the upcoming Congress soon. Nereya Ogheri and then Mika. Thank you, Amanda. Very happy to be here today. And congratulations on the book. I think it was a very, very necessary book and you did a great job. My name is Nereya Orica-Reño. I work in Denmark. I am an industrial PhD student with DTU, the University in Copenhagen. Hopefully finishing soon, hopefully. And I'm also a research engineer with VCS. VCS Denmark is the third largest utility in Denmark. And I've been working with VCS as a research engineer since 2016 and before that as a student. I'm very lucky that VCS is a utility very much committed to sustainability and innovation. And that has allowed me to work in very interesting projects on N2O all these years. I started working on N2O during my master thesis where I worked on operating our sidestream anamox reactors and trying to figure out a better way to control them to minimize emissions. But VCS had started working on N2O way before. I think the first project with Unicense dates back to 2011 or so. And we've had several projects over the year. Right now we're working on different projects. For example, trying to quantify N2O and methane using plume system from the whole facility. We've been trying to quantify nitrous oxide from trigon filters, testing technology to treat N2O. And in me particularly I've been working on MABR for my PhD, membrane-areated biofilm reactors. We've been testing this technology in one of our facilities for three years and N2O has been a big part of the project. I'm very much looking forward to this discussion today. Thank you. Thanks Naria and Amiko, last but not least. Thank you and thank you everyone for letting me join as well. So my name is Mikael Anderson. I have a background in PhD and actually in biotech. But as a career line just went up in bioreactor to the biggest one that we have at all, which is the wastewater reactor. I work as a technical director at Unicense and Unicense environment and have actually since 2011 been developing the liquid phase nitrous oxide sensor that we are today selling around the world. I have mainly been working first with the development of the equipment, but also understanding what are the dynamics in wastewater inactivated slot systems. And worked with Naria actually for many years now testing both equipment, but also small mitigation strategies and then working on the demon plant as Naria said. VCS has been instrumental as a utility in terms of letting us have access to test sites because pilot scale is not always good enough for full scale equipment tests. But the last I would say seven years I've also worked with understanding how to do mitigation in full scale. And unlike using a digital science it's been based on actually measurements that we have done and when nitrous oxide emissions are coinciding with the terminal of ammonia and so and also in the sidestream in terms of how to avoid the intense emissions that you get from these. And last I would say that the data that we collect we then use today to publish to correct both the ways that we calculate the emissions but also to get better empirical formulas for the parts of the dynamics that we can describe by modeling so I think this is my main focus today. Thanks very much Mika. With that we we've got we've got some initial questions and I'll ask you guys those but I'm pleased for those attending. Please feel free to contribute questions into the into the Q&A. So we've got a lot of questions in the box which you should see in questions in the in the side panel in the go to webinar panel. And just to say also if if we feel like the data connection struggling with us all on camera we can also we can also drop off so we'll see if we get any feedback that the the connection quality doesn't seem great then we'll we'll drop off webcams and we can just leave the questions up there. These were just some starting questions and I guess you know we've got an amazing panel of and depth of experience in nitrous oxide in in from many different angles and you know I think there's so much we could discuss but we I thought these these are some interesting questions and particularly reflecting on the title of this discussion which is which is you know climate action now so I guess just with that. And wanted to ask a first question, you know, do do we know enough to mitigate nitrous oxide now. And what are some of the key, key gaps or what else do we need to know. And I guess, oh, if it's okay, we'll go to you first and, and then perhaps ask Jose to follow up, giving you guys as as also as co-editors of the book for the chance to kick this discussion off. Sure, sure happy to kick off to share some of my thoughts. So if this is a yes or no question. As a scientist, I would say we don't know enough. So we always don't know enough to to mitigate all the nitrous oxide that we have saying from the different treatment plant. But the know doesn't mean that we can't have any action. So we definitely can start think about mitigation. But to me, I think there are currently two or gaps or barriers I think we need to think before we take any action. First, with mitigation strategy that we have investigate so far. So far, I feel that it is like one mitigation we found suitable for one plant, but it may not suitable to another plant, even with the same configuration. So it's not one source or thing. So how do you identify the suitable mitigation strategy for your plant. That's a question. So without monitoring. It's a very difficult to comment any mitigation strategy. That's the first thing I feel. Second, how the risk or impact of the suggested mitigation strategy, if we implement to the plant, how that may affect the performance of the neutral removal, or are there any consequences in terms of other aspects. That's also something we don't know so far. So currently in Australia, we have one successful case, which we have developed a mitigation strategy for one of the full skill treatment plant basing at light. So this is a SPR plant that by two rounds of monitoring by modeling that we proposed different mitigation strategy, and we evaluate the potential risks for different consequences. Unfortunately, the plant also like to take one step further after evaluation. And then when we verify we found it works, but it doesn't mean that all the plants will actually take that moving that that one step further. So I feel that that's something with the mitigation strategy, whether without enough risk assessment with that without enough evaluation, whether we can really take that step further. That's another, I feel barrier or gaps currently we have so far. Last one maybe so if we say the two currently will be knowledge sort of gaps. They otherwise mainly the technical right. So even you take mitigation you want to know how much exactly you have reduced. So that requires very accurate quantification or reliable quantification to support your mitigation. So if how effective it will be. That's another thing. And then, again, this requires a lot of a morning monitoring quantification that's the cost have to be considered as well. So I think I will just sharing my feelings and of course open for other people's thoughts as well. Thanks. Thanks for you and I think I mean that full scale mitigation study that you've published and I think you mentioned the, the fact that the utility which is essay water I think you know we're willing to go that one step further I think that seems so important in in the ability to test out some of these. Some mitigation strategies and the willingness to, yeah, to take that next step perhaps in the absence of the the regulatory need to do so just now. Just on that, Jose I know you. Yeah, you're working really closely on this as well what. Yeah, what's what's your thinking do we know enough now and what are the key gaps. Well, I think I would agree with Leo that we don't know enough. I think we're going to be continuously learning. Even, even if we, we start to mitigate into a, I think there's always going to be things that we learn, even from just a practical standpoint how we apply the knowledge that we have around the pathways and the influencing factors to specific facilities that have might have certain constraints or certain data gaps. I think as we do this more we're going to be learning more and how to better work around constraints and data gaps. I also agree that what you learn at one facility may not necessarily be able to apply at another facility and especially in terms of mitigation strategies. So if you blindly take one mitigation strategy from one facility and go and apply it at another, you may or may not be able to reduce the end to all because essentially each facility has its own fingerprint in terms of the combination of the operation, the configuration, the loading conditions, environmental conditions. And this is what makes it really difficult to apply the same mitigation strategy at one site to another. It could be that you might have a similar strategy, similar control actions that you take to reduce it, but that would be only if the, the combination happens to match to a certain degree, the combination at another site. And I think that as long as you have a framework to be able to account for any of these combinations, then it makes it easier to identify for a specific facility. What are the control actions that can be taken and what what is the, I guess, the, the cause of the end to all emissions. And I think that I guess another thing is in terms of trying to get an idea of what the situation is and what can be done. That's something we can do prior to monitoring with our end to a risk DSS platform. That's that's one of the ideas is that you're able to actually screen sites based on what sites might have higher risk. And not only can we see what sites have higher risk, we can see why they have risk and this starts to tell us what we might be able to do. But we can't know that for sure until we actually start monitoring, which is when we can confirm everything that we see. And we can actually measure the reductions when we implement the control actions that have been identified for that specific site. I would say in terms of key gaps. I think a big one is in the accounting side. Because and to is extremely site specific because it is extremely variable. It is extremely difficult to quantify into emissions with an emission factor approach. And unfortunately, right now it's what what is widely accepted is is this emission factor approach. So I think this is something that we really need to find a better solution for. And it's something that we at Cobalt Water Global have been working on and have been seeing some promising results. But it's good to hear that people like David are really looking into this as well, because I think it's important if we want to have a somewhat accurate picture of what our N2O emissions are at a specific site. And we need to be reporting those emissions. It's important that we have a good method because it's just not realistic that we can measure everywhere at once all at one time. So we need to have something that we can rely on in the meantime until we get to that those sites to begin our monitoring and begin our mitigation. Thanks. Thanks, Jose. Would anyone else like to come in? I think the when I think about those inventory challenges, I think what you see is also a potential risk that the regulator can't move as yet. Because there's not an effective means to baseline emissions and therefore any potential mitigation can't yet be added to a mitigation call the reduction if we don't have that agreed. You know, agreed inventory baseline that we feel is is sufficiently accurate. And my worry is that sort of delays delays progress. Although I think the good news is that we do see proactive utilities who are definitely taking action because it's the right thing to do or because there is that emerging regulation that maybe it may well be coming. And I just wondered if anyone else wants to to come in on that or else we can. I'd like to say something. In fact, this is a symptom of the fact that wastewater treatment designs are not very standardized. There are lots of small differences, although they may be broadly similar in many areas, there are lots of differences which tend to bedevil these comparisons around what's underlying the cause, you know, what's the underlying cause. And I think we owe it to ourselves as professionals to actively try to work on areas that look for what are the similarities in plants that tend to have higher emissions in other words to kind of religiously chase up the data. And as more and more people come on board with measurements and I'm sure Mikkel would be able to comment on this because, you know, you've been leading in this area of measurement. But I think I think the the onus is on us as as the professionals working in this area to look for the similarities because only that way can we then inform, you know, the people like the regulators or the people who write guidelines. The reality is we will have emission factor type guidelines for a very long time because it's simply not practical to to go down to the sort sort of next level of detail for many utilities, especially on every small treatment plant. You know, in Australia we have a very large proportion more than 80% of the wastewater is treated in just a few very large wastewater treatment plants are there only about 20 of them. So the opportunity is great because you can concentrate on those but for all the others they may account for only less than, you know, there may be small treatment plants of less than say 100,000 people but there could be hundreds of them. And it gets even worse in countries like like New Zealand, our neighbor where they have an even more spread out and decentralized population. So I think that's the key thing is that the gaps are there but I think we need to keep synthesizing and putting our knowledge together to understand the similarities and then kind of hone in on the key drivers of the key factors. Thanks, David. Yeah, just a comment and a question to the other panelists. In terms of mitigation, do we know enough. And you've talked about wastewater treatment plants. First monitoring before they cancer mitigating. Do we know. Do we have some sort of way of knowing this is this is too high. This is too low. When we mitigate what is good enough. How much should we be mitigating. Do we have any kind of. So, Nicole, would you agree. I think we have broadly a feeling of the range. I would, I would think so. So if we plot all the data that we have then we have a look at the we see, we see that when you get really really high in nutrient removal and then you also see that we have a fairly high load on the capacity in the emission as they they go up on the next question we can elaborate on that. I think in terms of what you should mitigate, we will not be able to avoid nitrogen oxide completely but I think we can get it a very low with the right design and the right capacity. As such, in terms of mitigation in Denmark, we will get back to that as well. But but here we said that we want to reduce by 50%. But the baseline is not qualified yet and will be over the next two years. So in terms of whether we do know enough, we don't know enough to make the baseline solid in Denmark and and so it's ongoing research here as well but it will come. But an area high number would be sort of more than 1%, I think we could say, and at a low number would be less than say 0.0, 0.2%, perhaps something like that. You know, all the data seems to show occasionally you get these very high numbers of 2345% or even 8%, sometimes 25%, but that's very, very unusual. Most of the data that I've looked at anyway from the literature sits in a band of around about 1% you know from plus minus about 0.5% of the influent nitrogen to the plant. Yeah, yeah, that's that's also my my my feeling that normal typical activities large long term monitoring is always going to be in this range 0.2 to maybe one, but mostly in the lower range but I'm not sure if we as a, if we have, you know, established what is slow, what is high, and when when we're mitigating and we say we want to mitigate 50% it doesn't matter if we started 0.5 or 0.8 or yeah. I think that goes to Michael's point about establishing the baseline and and that can only come when there's a good body of evidence for the geographic location and the type of treatment plan. I think I agree we haven't got this benchmark yet, but based on currently common sense. And if you have a high strength high loading treatment, like the digest leakers, you normally will expect relative higher emissions than just normal domestic wastewater treatment. And also if you are saying for domestic normal like strength domestic wastewater, you already reached about 2% that's basically already reached to the higher end. So this 0.2% with David mentioned is also we have seen, you know, quite large in the plant in Australia when doing the monitoring. And we see the other end, which is semi configuration, very same very similar configuration but reached to 1.9%. So, so we can see the trading same level of ammonia but with very different level of emissions. So definitely with the higher end. Maybe they have opportunity to reduce more, but in terms of how much we can reduce. I think based on my country knowledge and they are not allowed established sort of case with full skill mitigation implemented so far. With the one that we did in Australia we managed to reduce by 30% of nitrous oxide emission. So, and that plant is initial emission is less than 1% and it's after reduce it's like 0.6 or 0.7% emission factor. So, again, there, I think to better understand this, we need to establish the baseline, the baseline background monitoring using a great, great methodology. Then with the data we collected that will also be contributing to identify the similarity that David is looking for. And then that will helps we propose a more accepted, well accepted mitigation strategy to similar situations. So without applying a well agreed monitoring approach, if everyone is doing monitoring themselves with different method or different lens with different sort of standard themselves, it's very difficult to well extract that information from the data. So I think by working together jointly, I think if we agree acceptable approach and then we can using that approach and then doing monitoring collect the baseline data from a lot of different type configuration of treatment plan with different scenarios that will definitely help eventually to get a more sort of a great approach. Similarity sort of trend from that help with mitigation. Leah, you spoke to thought as you were speaking and I suddenly realized the methodology needs to include a set of parameters that define the reactor configuration and loading rate in a consistent way. Yes, so that we can make the comparisons. You know, so we need to be able to describe and define and compare these treatment plans and if you don't have that information you won't be able to do it. So I think that's what I've seen missing in some of the literature it's very hard to compare treatment plan configurations. And the benefit of a discussion like this as we get to start sharing some of this and no you've been exactly looking at this I think in your research just now so please go ahead and then we go to me go. So the last piece of research on my PC looking at the end to oh for the maybe are that we were testing. As I was writing the article I was facing this challenge. Okay, I have this number for my MAPR system is this low is this high. It's lower than IPCC is that good enough. So what I did, what we did is we scanned the literature for full skill reporting a fan toward data, but only taking data that had been monitored for more than a month, so that we were not taking just like spot campaigns that can create noise And then what we found was a very strong correlation between the nitrogen loading grade to that reactor that they were measuring and the emission factor like beautiful linear regression you have your activities large on the first part of the of the line with a very low nitrogen loading rate and very low emission factor, and then you have your size streams. Treatments on the right side with very high nitrogen loading rates and and very high emission factors, and then we use this benchmark to say okay my MAPR is loaded halfway. It's in between an activity is large and a sidestream. Where should that be in the line. That might have been maybe two 3% we've got point eight. Okay, that's that should be a good number for this for this specific loading rate. This is the approach we we found best. That's that's really good. Yeah, that's good and I think we need to think about maybe other parameters to you know such as the aeration type the aeration intensity. Oxygen particularly recycles internal plant recycles and how and where they positioned in terms of what we've seen on step feed systems new in South Australia and elsewhere so I just think there are a few other key things that we can identify that a process engineering things that will begin to help bring some order to the data or system system and systematic. And I think this ties in well with what Jose was saying saying as well in terms of screening a process for screening like what are the what is the process. What's going on within that process is it a nitrifying plug flow ASP which is very prevalent here in the UK. Or, you know, what's happening with the lickers is their side stream treatment, what type of variation system and control and control valve, you know, operation is there and I. Yeah, I guess this ties on quite nicely to the next question in our list which I've taken the list off right now but I'll post it in the chat, and also to a question we've had from from the audience which is, which is around, you know, well, question is, what, what will be the process treatment solutions in your view to minimize, or maybe eliminate nitrous oxide and I guess we could think about sort of short medium and long term process treatment solutions or mitigation strategies I'm going to go to you first Michael, but I'll just also pick up on the question from Kimberly which is, you know, will we constantly need to change our mitigation control actions based on the variation we see in sites throughout the year so I guess that's I know that's something you've been working on in in Denmark so if you happy to pick up that would be great Michael. Let me, let me thank you for the question and let me take that one first. So what we do see is that we have a high seasonal variation so that also means that the mitigation controls will really depend on on where you are in season and it's, it means to correlate this with temperature but we have actually not been able to correlate the high emission seasons, because they can be both winter and some of they are really dependent on a multitude of factors and I think this is where data science comes in as well to actually try to solve and decipher what goes on. But what we do see in many places is sort of spring emissions that come up. And here it's even out the load or reducing the amount of nitrates in the water whereas in the wintertime for example a control will be much more around controlling how much carbon is available for full denitification because then that is really struggling and remember that most of what we do in Denmark and in Europe will be full BNR plants that we are working on. It's a global session this one so we will see a lot of nitrification plants as well. So I think one emission strategy will work maybe for half a year or a few months and then you need to change or adjust your strategy and that actually calls for sort of automation in some sense in terms of mitigation. So that was to the question and then in terms of process treatment and solutions that will mitigate the polar answer will be that we do this apiotic instead of biotic and then we solve the problem but perhaps that is the really, really long term time. In the short term what we have actually been able to do actually within a few months is to achieve better than 50% reductions working with data and looking at what are the triggers at that type of time where we measure. And I presented IWA here in Copenhagen and we've done before. We see for example that diluting out the substrate so lowering the amount of ammonium per bacteria per time is really key to mitigate nitrogen. So that also means that if you have side stream operations that have a high strength, high turnover per volume then you will likely see higher emissions. And what actually goes on as cities grow is that we see wastewater treatment plants getting less rainwater in because that is deferred into natural water systems but then the city grows and the water amount stays the same but the strength increases in the wastewater and this is also where we see much higher emissions and that is actually from the bigger wastewater treatment plants in Europe for the most where we see the highest emissions. So on the short term it's really working with what you have in terms of infrastructure. And here we've had a great success by implementing simultaneous nitrification, denitrification processes where you try to both do nitrification and denitrification in the available volume that you have. And with this you can actually achieve very, very high emission reduction so up to 80 plus percent. But what you also benefit from is that you actually increase the capacity of the wastewater treatment plant or the treatment capacity of the treatment plant significantly by doing this. I just wanted to say that's the same path where we followed in terms of optimizing nitrogen removal in the 1990s. Because it also was about going for bigger treatment plants that have lower reactor loading rates in order to get the best nitrogen removal. This is at a time in Australia and in other parts of the world like the northeast of the US when the total nitrogen targets on the effluent were dropping below five milligrams per liter to three and even two milligrams per liter. And so it was the same thing where the carousel type plants that were bigger that have a big internal recirculation rate where the ammonia concentration in the reactor is spread out and is very low. They seem to be useful. So these seem to be a similar trajectory here. And that is that if you can advance the nitrogen removal and build systems that are lower loaded, it's an advantage. But unfortunately it got very expensive. And so the opposite direction became making the asset work harder to achieve the same or close to the same level of nitrogen removal but increasing the intensity of the process. And I think that led to a whole bunch of processes coming back that had been used in the 70s like step feed, for example, which is then the opposite where you don't have a big reactor recycle rate. But you spread out the the influence and you mix it up with internal partial nitrification in steps. And that, for example, is another way to achieve nitrogen removal and economize on space and reactor, but increases the ammonia concentration at specific points that are critical and then become big flash points for nitrous oxide. So I'm only drawing attention to those because those are ones I know but there are many permutations of the sort of thing. And I'm just agreeing with you that the systems that generally optimize nitrogen removal and increase or decrease the loading rate, increase the reactor size seem to be good mitigation pathways, but they cost a lot of money. My point here is actually that we use assets that are already there, but we use them better. And remember that size was also built to handle hydraulic load, but that is also now deferred due to climate change and so water, rainwater is, you know, we try to get that out of our sewer system, but that generates that higher load on the infrastructure that we have. Just bear in mind that when we do simultaneous nitrification denitrification, we are running at DO levels that we cannot measure with ordinary approach we are really, really low in oxygen. So in this case here we can always catch, you know, first flushed and so because we have plenty of aviation capacity available to remove ammonium afterwards. But I think there are also other technologies coming up where we can increase the capacity in the plants or maybe you should tell a bit more on the results when adding cassettes to activated flood systems. Yeah, thanks. That was the whole, you know, the whole hypothesis with the MAPR work and the N2O was we've seen before that if you dilute the load, right, if you get more, if you get your microbial community, that you don't stress them out, you will have less N2O emissions that seem to explain why we were getting so high N2O emissions in the sidestream. We also have an example from when we were running a monitoring campaign for the EPA here in Denmark, and we were not on purpose, like it did coincide that we were doing a monitoring campaign but we changed operation in our reactors from parallel, which they have been operated for for decades in parallel. We changed them to serious. So, so then one of the two reactors was getting double the load concentrations of ammonia were much higher. And the N2O just went like over the, like skyrocketed. So the whole idea with MAPR, the hypothesis is can we do intensification, can we get a lot more out of our reactors or out of our concrete and still have flow into emissions. And the results from the pilot are positive. I think on average we were getting median value of 0.5, 0.8 emission factor on average. In our case, because we were supplementing with fine bubble aeration in the MAPR pilot reactor we were getting a lot of emissions from the from the activated sludge, not so much from the MAPR. But we are so we expect in a in a full skill installation it will be much lower than what we have got. We're starting a new project now where we're going to retrofit one of our smaller wastewater treatment plants with MAPR so it's going to be a full skill retrofit. And we we plan to monitor we are already establishing a baseline and we plan to monitor monitoring N2O and see what is the effect on the whole treatment plant. And I wanted to comment on something that Mikkel said before because it's really interesting on our even on our MAPR work we saw that emissions will increase during the summer. And, but when we were doing the multivariate analysis, we couldn't find there was no correlation between temperature and N2O. So it was not the temperature, but again it was the load as a proxy for, so it was so temperature was a proxy for for the load but it was actually the load that was causing the N2O emissions. Yeah, and I think that's what might have happened in some of the studies where we've seen. Yeah, something because you get less dilution in summer. Is that the case? Yeah, less. Because it stops snowing. Yes, exactly. It never snows in Denmark anymore. Well, that's right. Yeah. So one comment on the temperature actually we have looked at it using DNA technologies just to see how the community changes and we cannot see a correlation between community temperature and emissions. But what we do believe is that some of the ammonium oxidizing bacteria have a faster turnover and ends up at nitrogen oxide at around 15 to 20 degrees. And this is why we see this in the springtime. But this is personal belief because we cannot see it with other tools and it's really, really hard to test this in the lab because it's only a few pure cultures of these that we have available. Yeah, can I share some of my thoughts with what Michael shares and David comments also Naread talks about the new technology. I think I can summarize the mitigation strategy. If you want to apply any mitigation strategy, I would suggest starting from the process based or parameters that you can easily manipulate, for example, dissolved oxygen. And also, if you can change the loading, if you use that feed, maybe change the ratio of your step feed. So that's something doesn't cost that much using your existing infrastructure. However, some of the mitigation strategy may need you to change or build additional infrastructure. For example, we have seen like one of our studies also deal with a step feed. It's, it's not some easily sorted out by change the feed ratio but you have also need to change the rest ratio. Basically, you have to provide more return activity sludge to additional steps to make sure you have enough bacteria working for you as well. So that's something we'll need the utility to build additional underground pipelines with the with the rest return. So that's basically not easy to be achieved or implemented in a short time. So with the mitigation strategy, I guess, again, definitely there are some common saying factors may attribute it to high end tool. And also, they're with the new technology, the nitri shunt, maybe are all animals. There are upcoming studies, but I think also with the new new technology or new sort of research coming in, we probably will also get more understanding about what are the key operational parameters may affect a tool. So basically, again, with the mitigation strategy, starting with something may easily to change. And then based on the monitoring. And then if you get the already set up, I think once you start monitoring, you probably can correlate some of the emissions with the operation with the specific features of your plant and see if any of these that may attribute and help you to identify something you can change for the operation. Thanks. Thanks for you. And I think, you know, it's been great to hear about the mitigation that's happening now already things like dissolved oxygen set points, you know, things that we can easily change think promoting simultaneous nitrification denitrification, you know, working to maybe ours which could help us with future augmentation and also perhaps tackle capital carbon as well as process emissions. And then, you know, future future thinking beyond that. I just wondered, Jose, if you wanted to to, yeah, to come in and maybe tying in with the another one of the questions that we've we've got which is around around data. So, you know, what are the opportunities when we look at the process data we have. And I guess and the data that we can get from monitoring that could help drive those mitigation solutions and, you know, maybe you could talk a little bit about the work you're doing and also pick up on the seasonality and maybe the need to revisit sites to to keep a model updated. Sorry, that's too long a question, but please, yeah, please talk to this a little bit because I know you're doing some really interesting work in this area. Sure. So, yeah, I guess one thing I just wanted to comment on with regard to like configurations. And I think it kind of goes back to what I was saying in terms of looking at the combination of the operation and loading environmental conditions that contribute to a specific situation in terms of the M2O emissions. And I think it's really not so dependent on configuration, but operation. So I think theoretically you can have any configuration, but if you have the right conditions, it doesn't matter what configuration you have, it's going to be more related to the operation that's going to drive whether you have high or low emissions. But in terms of like the different combinations and what are the control actions that can be taken, one of the things that we've done in going through the literature and the research was develop a M2O risk knowledge base. So we can look at the risk, quantify the risk and be able to see what is contributing to this risk and what can be done to avoid the risk and reduce the emissions. And by following this, we can do things like increase dissolved oxygen or decrease dissolved oxygen or increase carbon dosing. So if we're able to look at any situation, we should be able to identify what control actions can be taken using this framework. And we've had success in the Netherlands working with Water Board de Domel, Water Board ANMAS, where we've achieved up to 90% reduction on M2O just by adjusting the dissolved oxygen. Also recently in the UK working with Welsh Water, we had 80 to 90% reduction again just by adjusting the DO. And what we like to do is really fine tune the current operation and the current control because it was set up for a specific reason to meet a specific effluent quality. So we don't really want to change that, but if you look at the default operation, you find times where they can potentially be at high risk either due to high DO conditions or due to low DO conditions because each one is going to implicate a different M2O pathway. So what we try to do is fine tune it so that we get them away from those high risk areas, but keep the same control. And I think that this, we've had a lot of success with this approach. You could then to the future, you know, we've had a lot of success with this approach. And I think that this, we've had a lot of success with this approach. You could then to the future, I think, or even now look at really advanced control, taking a lot of different things into account and using things like AI and machine learning to help guide what you need to be doing to balance all of the different objectives because there could be energy consumption. Minimizing energy consumption as an objective, obviously maintaining the effluent quality, which should never be compromised, but there could be objectives like minimizing chemical consumption. And now obviously we have M2O in the picture that we need to take into account. So you can get into some really advanced and complex control strategy to balance all of that. But I think that in the meantime, just fine tuning the current control is important. Another comment on the seasonality, what we've seen a lot is with the default operation, and of course we're tracking the risk. You see the risk profile change over the course of the year where you might have, and typically it's you have high risk due to high deal conditions in the colder months, and then you have high risk due to low deal conditions in the warmer months. And this is not surprising if you think about it because with the higher temperatures, you have higher activity from the bacteria. And I think operators like to pick up on this because they can get the same treatment or even more treatment even by turning down their aeration. So in the summer months, they're able to save a bit on the energy consumption, but still meet their effluent quality. But inherently what this does, it puts you at risk due to the low deal condition. And if you're at risk, and you have higher activity, you tend to have higher M2O emissions. Because you're stressing the bacteria under conditions where you're going to be prompting a specific M2O pathway. And this can happen with high deal conditions as well as with low deal conditions. So this is something that we've been seeing with just the default operation. And of course what we want to do is change that so we can avoid these situations. And I think that in terms of the data question, I think that with just the current data collection, you should have enough to be able to tell you what you might be able to do because most places are monitoring at least at a minimum dissolved oxygen. And because this plays such a big role in what your M2O emissions can be, as long as you understand what the other process conditions are, you should be able to come up with a strategy to either increase your dissolved oxygen or decrease the dissolved oxygen to a point where you're not negatively impacting the process, but still reduce your M2O. Thanks Jose, Mikal. Did you want to come in a bit because obviously the S&D, you know, it's relying on a very low level of DO. The microbial community and the process type that we're talking about doesn't matter in this conversation, but we see mitigation opportunities in both areas, I would say. One comment is that actually in northern Europe, at least in Denmark and in other countries, that you don't use DO at all for controlling our wastewater treatment plants. It's ammonium-based or nitrate-based controllers and all of a sudden the dynamics are very different and not really driven by oxygen, but driven by something else. But of course, then you push the sludge into another community than standard nitratation denitrication. So as I said before, when we run a simultaneous nitratation denitrication, we actually don't want to see any oxygen on our oxygen sensors that are still there. So we don't see low DO as a risk. There you are. Did you want to? Yeah. And Jose wants to follow up on that? Yeah, sure. So when we're talking about adjusting the DO, it may not be because it's controlled with DO, but if it's ammonia-based control, yeah, it's going to be controlled based on the ammonia concentrations, but there are limits that you set with the dissolved oxygen. So based on the range, if you're measuring the dissolved oxygen, you're going to see a certain range of dissolved oxygen, and that range is where you can see periods where you're at high risk or low risk, depending on what your ammonia concentration is. And this is what we try to find too. This is what we have been able to take high emissions to very low emissions. And just to point out here in the UK, for example, we aren't yet seeing, we're seeing a lot of nitrifying plug flow activated sludge plants that we haven't had TN consent. So we do have a lot of legacy DO controlled nitrifying ASP. So I think it really, whereas a lot of the research ran into has been for nitrifying and denitrifying systems, and much of the work right now is going to have more, you know, may have more advanced, the existing facilities have different control. But I would say there's definitely opportunities around DO set points here for the asset base we have for now. But yeah, I think this is really interesting. Neriya, did you want to come in and then we might move to the topic of monitoring and accuracy? Yeah, just a short comment on the mitigation short, mid, long term that I think I didn't answer before. I think we're going to see a lot of utilities doing mitigation like the one we're talking about right now, short term. I think midterm, we're going to see hopefully, I don't know if hopefully the regulation like the one that might come in place in Denmark in a few years. I'm excited about a project we're running where we're testing catalytic treatment for off-cash. And I think that might be a long term. That's how I see wastewater treatment plants long term, fully covered and either treating the off-cash or finding a use for everything in it, including the N2O. Yeah, I think there's opportunities for new technology in that area as well, but that will take a very long time. And we don't even know if it's feasible. That's something we're trying to figure out with our project, whether that's cost and environmentally feasible. But if it is, it's going to be an interesting solution. Thanks, Naria. And is it fair to say that project? I think you're focusing on an existing covered side stream like a liquor treatment plant because it gives you the ability to have those emissions captured already. So this is a really nice place to start as well because it's very concentrated. Yeah, high amount loaded. We're testing three sides. So we're testing two mainstream treatment plants in Denmark, which are fully covered because you're brand new. And we're also going to test that Ibimule, which is not covered, we will test on our side stream, which is the one unit that's covered. And it's also more concentrated. So we'll test both mainstream and side stream. Brilliant. Thanks. This is really, really interesting. Can I comment down? Yeah. Yes, of course. Yeah. Well, I think I got two comments. One is about the, like, how long we should monitor it. I feel that so far we do not have a conclusion yet. But if you can notice some of this operational change happen to a plant, that's definitely you should monitor whenever, for example, set point of DO whatever you think you will change that. You shouldn't cover the monitoring on both this change. And also if the plant is receiving variations of the loadings in summer or winter. Also, if you, we are not sure whether it's the temperature play the major role or it's loading, then I would suggest that we should cover those change of seasons as well. And maybe I think that's a few sampling round that should last at least a few months that you see whether these different seasons all have different variations in terms of into all. So that's my personal feeling. We don't have any documented regulation in terms of the length yet. So this is the first comment in terms of how long we should recovering from monitoring in terms of the deal. So we with the with the mitigation that we have implemented in the plant. What do we suggest the ease and S and D so basically that is the one of the strategy suggested by our modeling. Our first strategy is basically get a better deal set point control basically control at 2.5 the second is basically reduce that set point to open fire and push and S and D happen. So based on what we found, we didn't say that the low deal affect the into a mission at all. In fact, we found that reduced the into a mission factor by 30%. And also in terms of the effort and quality, we did not see any compromise of a natural removal in terms of the treatment of the plant. That's what we have observed. So in terms of the filamentous bacteria filamentous bacteria, I think that's asked in a question by implementing. We didn't say this slash bulking happened. That's I think this because of filamentous bacteria is many, many reasons. The deal is one only one of the reasons. So I cannot say that this will not trigger but at least for the plant that we implemented we didn't see the problem of filamentous bacteria, but there may be other reasons which will trigger filamentous slash bulking. So that's not not something we have saying so far. And also in terms of whether reduce or change deal, I think basically is linked with what is the reason of your until generation pathway. They all play a major role if if it's really affected by a nitrifier, because we see and dissolve oxygen really affect a lot of AOB activity. So if you a lot of until is coming from your AOB based nitrification pathway, the deal change deal may affect that effectively. However, if it's coming from the notification basically you don't have enough carbon source change deal does not help you need to give enough carbon. So I think again, how which mitigation strategy you want to adopt your need to monitor and you need to link that with your plant operation with the treatment performance you have and then identify the potential reasons about until generation. So I think that's the sort of comments I would like to share based on a previous discussion. Yeah, go ahead. Yeah, I was just curious. When you went from high deal to only low deal. Was this. Did you see, but there are still N2O emissions, right? You said there's 30% we couldn't completely get rid of N2O from that. And the emission factor reduced, but we still have until it's just the something coming with the nitrification denitrification. We did see. Okay. I just say we we did say the reduction of N2O generation. Because in that plant. Yeah, that that plant is mainly attributed by the AOB based pathways. So. So that helps reduce to reduce that into all from those. However, for the other plant where we see obviously was mainly attributed to denitrification. A lot of times the playing with deal set point doesn't really help with that. Yeah, so I guess one thing that we have we have seen which is consistent with what you observed in that case is that you could have situations where you have to both AOB pathways occurring. Because that, as we mentioned, like for ammonia based control, for example, you, you're switching back and forth from higher do to lower do. So if you were essentially to change that so that you only have low do and you're trying to prompt SND. What I mean, this is my hypothesis, but the effect of that is that. What I mean, this is my hypothesis, but effectively what you're doing is you're eliminating one of the pathways. So whether you go to only high do or whether you'll go to only low do you're you've taken out one of the pathways. So you should see some reduction. But not elimination because you still have one of the pathways occurring. And then in terms of the denitrification, you're totally correct if you're changing do and then a part of the process where you have nitrification happening. You shouldn't see that help you much with the denitrification. However, and depending on the configuration, so this is where configuration can can play a role that that the higher dissolved oxygen from the nitrification will get recycled in the internal recycle to the denitrification. And what we've seen in those specific situations is that lowering the do if it was high in the nitrification part actually helped reduce the end to in the denitrification because now you didn't have dissolved oxygen contributing to incomplete heterotrophic denitrification. So I guess it's really configuration dependent, but again, regardless of configuration, there are things you can do. And with that, I think it would be good to move on to the key challenges in monitoring and the accuracy of monitoring. We've talked a lot about the plant specifics and the need to go to sites, you know, long term or intermittently over the long term to try and understand those seasonal variations. But I guess I'm going to ask Mikkel first, you know, what are the key obviously you've been involved in the development of the world's only liquid phase nitrous oxide sensor to date. We can measure in the off gas as well. And one of the questions from the panel I think is if you know if, if, if measurement technology wasn't a problem, you know, what would we ideally be monitoring to optimize for for mitigation. But yeah, Mikkel, if you could just talk a little bit about the challenges, you know, what is the accuracy we have in monitoring and what else, you know, what other work is being done and needs to be done to really help us mitigate at the speed that we might say is required to address the climate crisis as we see these horrific floods in, yeah, around the world. Well, I represent the equipment that sort of takes the bottom up approach in terms of looking at the what is actually produced in the liquid phase and then we calculate the emissions. And we are, I would say we have an accuracy where we are within 20% from from the real situation that is based on on inaccuracy in sensing, of course, but also in terms of airflow measurement. And then we have the off gas equipment that is that is also run and since it's calibrated against certified gases, the gas measurement there can be quite, quite good or we set that as the standard from which we then measure our 20% off as a maximum. But airflow measurement in the hood says actually also been joined to have the real, real challenge to know what is the airflow in in the hood. So that's something to be aware of. But if you look at the, to the question that we do have the monitoring, where would be the monitor, I would really go for the rate of change of nitrogen oxide because that is actually where I believe that we need to go in order to make automation in terms of of controlling geo ammonium turnover, return cycle of nitrates and so forth is really to see how the concentration of nitrogen oxide changes as a function of any controller in the system. We do know in terms of measuring that it is where the ammonium is turned over that we need to look first in terms of nitrogen oxide emissions. But following up on the discussion from before, be aware that if you are turning over ammonium in a high background of nitrates, then the emissions will go sky high. And that's because now you start all the pathways that you talked about before. So it doesn't matter whether you have low or high as long as you turn over ammonium and a lot of this will end up as a nitrogen oxide one, one way or the other. So it might look textbook clean in terms of modeling and so, but actually in reality, it is a mixture and quite a bit of genius as you go through a blood flow tank, or as you turn up and down, but measurement in a completely covered plan will most likely give you the most accurate climate emission, but solving the emission problem is then the next genus that you'll have in a system like this. So measure where ammonium is turned over and then look at the emission either calculated or measure with our gas instruments would be my answer. And the risk of just to comment on the uncertainties key factors, just transporting them from one plan to another that will always generate a higher uncertainty than whatever method that we use on site to measure with. So I think that that is one thought to keep in mind that the key factors are really chopped down and they are very good at making policies and regulations and so, but it becomes to sort of the third bottom line for utility then measurements might be in any form, much better solution than a key number. Thanks for that, Mikal. Would anyone else like to to come in on that I know, for example, a lot of the work to date in academia has been on off gas, using off gas monitoring. And I think now there's we're seeing some sites that have both liquid phase and off gas and I think there's challenges as Mikal says, you know, there's challenges with both but I guess some. Yeah, what would your thoughts be. Well, just sharing my experience we have got so based on what we have found we found we talked a lot about seasonal variations, but indeed within the plant. There is a big spatial variations as well. That really put the question, where you measure how many locations, you should measure as well, because if you put the hood, all the sense at different location, and then you will get different dimension factor. So, I think that's the first practical question a lot of utilities asking how many places I should measure. And how many senses how many food I should put. Second, where to put them. Right, so, so I think Mikal shared some about very good thoughts. In terms of like ammonia turning over, like when you see this, the ammonia variation concentration happens within your in your plant you may see there will be variations but into a generation. Another common feature we have seen with the variation. A lot of times it's really depend on how many zones that you control your dissolved oxygen set point. If you have a long plug flow reactor, you actually already divided into three different aeration zones with different set point. Then I would suggest naturally you would like to monitor each of the zones, because you have a previous key control parameter that in differences. Not only the way the flow variation concentration variation, but also with a different control parameter variation there. And also, in terms of the challenge with the hood, of course, it is the equipment to solve the whole setup, because you when you capture it you have to capture simultaneously right so that means multiple locations, you're measuring simultaneously. So it's an automated control gas phase control channel, you have design you have a PLC you take the gas concentration from different location you have to monitor all the flow. And also you want to know the temperature different locations and many parameters that you have to capture. So it is difficult also very costly. And also another practical sort of thing we we have seen is when we get a lot of this data coming in utilities don't know how to analyze the data as well. So that's all like challenges we are facing in terms of the monitoring. And also, currently we try to also address another very practical questions with the plan that we are doing monitoring and Melbourne water. Very obviously that we believe with the flow rate, you can use either the plant flow rate if a boot aeration monitored accurate, or you use the hood capture flow rate in theory. If you it's all accurately measured, and then you should have the same flow rate and that's key, based on assumption that your measurement you have a really representative flux from the covered area. However, we found these actually affect some variations in terms of the flow, so the method itself need to be verified. And also with with the liquid phase I think with the unisense sensors. Also, we found some in overall it aligns with off gas very well. But one thing is, sometimes the sensor we did see the signals sometimes it lines well but occasionally didn't align well. Secondly, indeed, we have a less lifetime of the of the sensor compared with currently the gas phase analyzer they have. I think that's all practical situations we are facing. So with all these challenges we have, that's probably next thing we have to work together again to work out what's the best, what's the best monitoring protocols we should provide. A hands on protocol that industry can use by themselves and guide them to get the right equipment and pull the right location and capture the data and analyze what they have. So only if that is available, then that will allow the what we have discussed, like to link this with a plan operation and the think about mitigation then only if the first step become available we can enable the next mitigation steps. Thank you. And just as we come to a close, I mean, I think, you know, we've gotten bogged down in a good way in lots of the detail and lots, lots more challenges. But I think at the at the beginning we've established that, you know, there are there is action happening already. And we know enough to do mitigation if we go site by site we can learn we can take action just I guess probably a possibly a final question or we might have one final round. But and David, I'm going to go to you. You know, what do you think I think regulation was mentioned, you know, there was a really interesting LCA paper out that Michael recently shared which in the abstract suggests that we need a carbon tax for nitrous oxide to drive to drive momentum. But David, what what do you think will drive more rapid action on nitrous oxide. Thank you, Amanda. I think largely the driver is going to come from the governance of water utilities. Because if you think about it, at a societal level, or at the sort of central government level, nitrous oxide emissions or waste water treatment emissions in general are a very small fraction of societal greenhouse gas emissions. I mean, even if we're out by a factor of two or three, it doesn't matter. It's still probably less than 1% of society's emissions, much less than 1% in the case of nitrous oxide. So I think if we're going to wait for central governments to come along and legislate in this area, it's going to take a long time because they got much bigger fish to fry. But what waste water treatment systems do is they aggregate the emissions. So whilst the emissions per person might be small, a water utility has an opportunity to deal with the emissions of potentially millions of people at one point, which is the waste water treatment plan. And so if the water utilities themselves have have governance, in other words, they have targets or objectives that might be either local government or state government perhaps driven or even just by their own boards accountability in terms of the environmental track record. These will be the things that will drive it. They'll be wanting to be making their contribution that the water sector would be making its contribution. One of the problems I think is going to be the cost of the mitigation. Yes, we've been talking about some of the low hanging fruit and we've said, you know, we can bring the emission factor or the degree of emissions down substantially, but the complete elimination could be tricky. And I think in that area, it's more likely to be cost effective for the utilities to generate carbon offsets, just because of the cost. You know, if you look at the cost of some of the major capital work that goes into these waste water treatment plans, once you've got beyond just the operational changes, which could could actually save you money as you know, Jose has been highlighting and you and others. But when you start getting to big capital infrastructure changes such as having to cover reactors and treat treat the off gas, I think it's a great idea. It'll do a lot, but that's only going to happen on the really big treatment plans where you get economies of scale. But for the rest, I think we could be looking at costs per tonne of CO2 mitigated that could be in the order of hundreds, thousands of dollars per tonne, whereas the cost of carbon in the market that we could generate by things like changing practices in agriculture or you know, getting carbon back into the soil, there could be many other strategies globally that would be more cost effective and I think what utilities can tap into that. But largely it'll be driven by I think policy from within the water utilities themselves rather than central government or legislation. Thanks, thanks David and I'll just briefly I think to finish up, go around to everyone. Well, just just first I think the interesting thing around the nitrogen cycle is that these nitrous oxide emissions emitted in waste water treatment because of the protein and the nitrogens we ingest and we excrete. And we also put a lot of nitric, you know, nitrogen based fertilizers on the agriculture that supports the food system that we that we rapidly need to change for, you know, in response to the climate crisis as well. So when we think about recovering trying to close that nitrogen loop, I think there's some really interesting implications that go much broader than the national inventory, you know, the waste sector, which is obviously where our emissions fall. And we do see utilities who are progressive trying to try to work around that but just in a in a few, a few seconds each I guess what excites you most about nitrous oxide what keeps you going each day. I'm going to start with you. Okay, David, you can start what what excites you what what what excites you. Why are you still here. Why are you here late. Well, 20, 20 years ago I stood up at a conference and I spoke about nitrous oxide and I got no questions. And there was little interest at all exciting that excites me is that there's a growing tremendous swell of interest and that's how the world's climate crisis is going to be solved albeit a tiny level here. It's the enthusiasm enthusiasm and people coming to the party. Thanks David Maria. Absolutely agree. I think the level of awareness in my very short career. I've seen that change enormously. And I think utilities now. I think I agree but I also think there's place for bottom up approach for this and I think our customers demand of us that we're responsible. And I think we've seen that and now we see utilities pushing technology providers and regulators as well. I think. Yeah, I think there's, there's, there's, there's, there's so many utilities interested in this and it's a very, very odd now that you are attending a conference and there's a new technology and and who's not who's not showing data on and to all, and there's not a question. What about the end to all. So I'm very, very excited that end to all is going to become just just a natural part of the nitrogen cycle and the wastewater treatment plans, just like ammonia nitrate and nitride are. We have it present every time we make a decision. It's not going to be cost and effluent and so on. And so it's going to be part of the decision. It should never be the primary goal. I think our primary goal is to is a clean affluent and some utilities might better spend their money, saving energy or producing energy. But I think and to all should always be part of the equation. Very quickly, we're going to say. Okay, well, likewise, I'm excited that that the interest is finally growing. But I'm also excited that we can actually do something about it now. I think in terms of monitoring, we have excellent instruments knowledge for doing monitoring. In terms of identifying control strategies using the data, we have good, good technology to do that. And I think we have a lot of process knowledge. So there's really no reason we can't leverage each of these things to start taking action today. And I think what's interesting if you look at the, at the iPhone, the first iPhone that came out is is terrible compared to the current one. So obviously we're not perfect right now, but we can certainly make a difference. We can certainly take action. And we shouldn't wait until we have everything perfect to get started. Thanks Jose, Mikal. And then final word to Lou and we've overrun, which is my apologies, Mikal. Me, I think actually that monitoring spawns a lot of kickback in terms of process understanding in terms of actually using the the assets that we have in the water cycle already and then actually being able to improve them but now in a more sustainable way. I think in a bigger scale than monitoring actually leads to a lot of other, both commercial but also societal benefits that I enjoy seeing spawn now with, you know, Indian companies around the world also being interested in natural oxide now. That is new five years ago that was not the case. Thanks, Mikal. Yeah. So I think climate change that's a responsibility should be shared by every industry by every sector, although we are not the biggest CO2 or carbon contributor but indeed wastewater contribute a lot of until and until is not a greenhouse gas that can be backed absorbed back in the carbon cycle once they emitted in the atmospheric the other year, and also wastewater. We are very, we are highly engineered industry. So human designed this process. And then this is the place that we should have opportunity to reduce it. So it's much easier compared with other sectors, I think. So I think that's a responsibility for us. And then also as a scientist I have the passion to also dig into more fundamentals to understand how exactly bacteria produce this. Thanks. And with that apologies we've run over run five minutes I hope you'll agree it was a really interesting discussion a huge thank you to the panel for dialing in from all around the world. We will answer questions that we didn't get to. And please, yeah, please reach out and get in touch and I'll enjoy the rest of your day and I'll close the webinar now thank you again for joining and thank you very much to all you on the panel. Thank you. Thank you, Amanda. Thank you, Amanda as well. Thanks everybody. Okay. Thank you. Bye. Bye.