 Hello, good morning, good afternoon, good evening, wherever you are, welcome to this IWA webinar on Accelerating Sludge Management Choice Sustainability. My name is Richard Tsang, I am a sludge treatment and management specialist with CDM Smith in the United States. I'm also the current chair of the IWA Sludge Management Specialist Group. Welcome to our webinar today. We have a good program for you. Before I get into the agenda, just a little advertisement for our group. Sludge Management Specialist Group will introduce with all kinds of issue related to sludge. And not only wastewater sludge, but other sludge as well. So if you're interested, please join us. And you can easily find us on the IWA Connect website. Just so you know, these webinar will be recorded and the slides and presentation will be made available towards on the IWA website. During the presentations, your audio will be muted. So there are two ways that you can communicate with us through the chat box. Please use this for general requests. You have comments and other things you can use that. But for questions to our presenters, please use the Q&A box. And if your question is addressed specifically to a speaker, please put their name in so we know who to direct it to. So now let me introduce today's speakers. We have Ms. Puja Doshi. Puja holds a master degree in law and economy and anthropology. She is a certified project manager consulting and developing projects, speaker and trainer with engineer without borders in Germany. Then we also have Professor Ludovico Spinoza for over 41 years. He was the senior scientist in sludge management research with the Italian National Research Council. He's currently serving as expert member on sludge standardization and coordination of Soyer and Wase at UNI, which is the Italian standardization body. Dr. Spinoza has been chair of this sludge management group for a couple of terms. Also received a research medal. He's also an IWA fellow. Here is the agenda today. We just done the welcome introduction. We're gonna have Dr. Spinoza speak first followed by Puja. And that would be some conclusion remark followed by discussion and QA session. So with that, let's move into the presentation by Professor Spinoza. Okay. Thank you, Mr. Chairman, for your kind words. My presentation, it will be dealing about the technical aspects while the presentation that we follow by Puja Doshi will deal with institutional and technical aspects. Institutional aspects. Next slide, please. I start by remembering that the target 6.3 of the sustainable development goals of the UN agenda, is 2030, which focus on reducing pollution and increasing reduction by recycling and pushing towards the achievement of sustainability. So it is necessary now to push ever more decisively towards the achievement of sustainability objectives in the governance of wastewater and sludge management systems. I like to remember also that it must also not be forgotten that an effective and real achievement of sustainability objectives cannot disregard or expect for circular economy and thermodynamic principles. The definition, I start with the short definition of the three aspects, the three principles that I mentioned before. For sustainability, there are many definitions, but where that fits me better is that sustainable situations occur when consumption of renewable resource does not exceed natural stability for their replenishment. This means that sustainability must be seen according to three points. It must be environmental variable, economically convenient and socially acceptable. And you can see in the figure that there is an interchange between these three points. What is important to say that sustainability depends on the territorial context in which it applies. So it must be seen from a relative, not absolute point of view what is sustainable, for example, in an agricultural area may not be sustainable in an industrial land. And this is very important. About the circular economy, it's necessary to... the definition is that it defends circular economy, defends an economic system designed to regenerate itself. It is mostly often represented by a circle, only a circle, and this is wrong because for any process we can leave, in all cases, some losses to be replaced by new resources. So the correct representation is what is seen. But this is valid for one process. The water treatment system, the water treatment is large management, consists of a sequence of a number of single processes and sub-processes which... the challenge is to reduce the total amount of losses for all the processes included into the system and subsequently the need of new resources which must re-establish the mass energy balance. Normally, I just like to remember that the circle is without the beginning and without an end is a figure that has always represented the harmony and the intellectual dimension. That is the spiritual world, while the square that is the polygon made of false glides represent rational thought, logic, and the physical world. So in the attempts of humanity to reach a circle starting from a square polygon, a four-sided polygon we can say that we can improve the number of sides of the polygon so with the greater the number of sides of the polygon, the greater the approximation of the system to a circle can be seen in the figures in the bottom. I just like to remember that in our region, in the southeast of Italy, near my house, there is a castle built in the 12th century which is the tentative to reach the circle which represents the circle. This consists of eight sides and each of the sides is connected to the previous wall at the following side with eight rectangular towers each consisting of eight sides. So we have in substance this is an architectural representation of a system in a circular economy concept. However, the problem of circular economy is that the social dimension of sustainability is only marginally addressed as it is mainly addressed to economy and the environment. The thermodynamics law are often forgotten but we have to remember that all human-operated transformations are not perfect or fully reversible so they are subject to the three laws of thermodynamics. The one is the energy is invariably conserved but assume different forms some of which cannot be conveniently recovering so energy matter losses are always occurring. The entropy is the second principle entropy is a measure of the disorder in an isolated system and the second principle of thermodynamics say that entropy constantly increases thus meaning that the worst state than before is always involved and more disorder. The third principle is the absolute zero value is impossible to be reached by finite processes so that perpetual motion infinite recycling is impossible. These are three principles that must be keep in mind. Just few words about the situation the water sludge is. Sludge is the unavoidable by-product of the water waste water treatment system. Just for your information in Europe the average generation rate is about 59 gram per capita per day with a big range from 20 degrees and 118 in Portugal and these differences can be explained in terms of population server type of waste water treatment and water availability. The problem is that although sludge accounts for only about 1-2% in volume of the treated waste water it contains most of the pollution and this both difficult and expensive to be handled often often required over 50% of the operating budget for the waste water treatment plant. However in the conventional during the planning in the conventional planning or designing of sludge treatment and disposal of the often the sludge is considered of secondary importance with respect to the waste water treatment system and this can be explained because it is placed at a physical location is at the end of the water of the water cycles so it is underestimated but what we see that is more important is the waste water treatment plant to the sludge production to a possible reuse of sludge but the reuse of sludge is directly connected directly influence the waste water treatment to comply with the SD the sustainable development goals of the UN agenda we need it matters that we have to look at the sludge management of the waste water treatment plant aiming at accelerating the development of more sustainable strategies oriented to maximize recovery benefits instead of simply disposing way to accelerate sludge management sustainability we can consider two points consider sludge management as the locomotive and then we explain in the following and taking into account both technical and institutional aspects the technical actions are aimed at improving sustainability by maximizing the recovery benefits while for the institutional actions the Pujadoschi will speak in the following presentation so as I measured before sludge the treatment and disposal of sludge is not generally in the conventional way plays a secondary role during the design planning phase of waste water as it is considered the terminal due to its physical location but forgetting that the most appropriate treatment for the sequence of treatment to adopt for the waste water is strongly driven by the sludge disposal options available in the specific local context it is in no sense to produce sludge for agricultural use if there is enough land in that area or in the industrial area to produce sludge for agricultural use consequently sludge management should be conceptually this is a question of concept considered as the locomotive of the water cycle train we have to start from the end finding which are the particular option for reuse available in a specific context and go back to the waste water treatment to adopt the treatment to obtain to get the results the characteristics of the sludge we are needed for a specific type of recovery in a sustainable sludge management network we have to consider that I represented this as a with an aeronautic illustration but it is not possible to fly directly from the origin to the destination we have to introduce some treatments within these terminal points, initial and terminal points so we need in this context there are two points that constitute that are really and hub as they are always can be found in all treatment sludge management systems these problems are the reduction of resources through stabilization and digestion and the reduction of volume through tickling and devotee so this means that it is also important to pass through these two apps to improve the sustainability and sustainable management it is also important to remind that any stabilization digestion methods also reduce the sludge amount by degrading volatile solids for the reduction of nuisance the new developments consist in the first limitation at the source of harmful substances entering the wastewater treatment plant this is very important develop strategies and technologies to improve sludge quality in order to reduce nuisance health risks and handling costs so the slides are shown some improvements for anaerobic digestion or for aerobic digestion and the new research areas include the presence and fate of estrogenic compounds, enzyme treatments molecular methods may meet us on microbial population as regards the reduction of volume we have two possibilities we can take place in the water treatment line there are several processes by cellular leases increased age of sludge optimization membrane technology, thermal electronics etc. or reducing the sludge volume within the sludge treatment line and the advancement of this field consists in more effective chemicals to make easier the solid-liquid separation the use of biopolymers to decrease the environmental impact and the new technologies based on the combination of mechanical and other forces electrical field, thermal supply, ultrasound etc but what it is important to say is that the goal is not pushing sludge production toward an absolute minimum but making sludge amount volume compatible with its final destination and the best overall energy material balance so it is not necessary to obtain the lower volume but we need the volume that is sufficient for the specific use or reuse that has been planned another important point is that digitalization can affect both technical and institutional aspects of wastewater large management on the side of technical aspects digitalization could be of great help as it allows greater operational capacity and control to be obtained through real-time monitoring so it is possible that this system digitalization can be described as the convergence from an operational technology of the physical set with the informational technology which is a digital twin that online can change the operating variables of the plant, the physical plant to change to improve its performance which are some examples of processes that can be coupled to a digital twin with the wastewater that we did a wastewater large treatment plant in stabilization digestion we can monitor the biogas composition to control the laser processing abilities another possibility is the continuous monitoring of orders which consequent modification of operating parameters another example is the installation of a form sensor to activate surface charge or removal options trap on gas line and protection to the pressure release and this is some example that can be buzzed on the availability of an appropriate sensor to measure, to control, to monitor these characteristics in the thickener dewatering we have many more possibilities options for example in a gravity thickener we can adapt polymer dosage to settling velocity in the centrifuge through the digitalization it is possible to adapt the polymer dosage and the mechanical operating variables of the machine like differential speed and conveyor torque to cake-centrate suspend the solid content and flow rate of the incoming sludge so we can maintain the performance at a good level for filter pressing it's possible to regulate the volume of mass rates the pressure rise and mixing energy to optimize the filtration results and minimize requirement of conditioning agent. Polyboconsumption is a we already seen in the previous three examples but polymer consumption is very important because we can monitor the polymer dosing from a z-potential streaming current measurement or the direct measurement by spectrometry or spectrophotometry or rheology using an inert race electrostatically bound to the floccular and this allows the polymer consumption to help to be optimized and consequently the costs to reduce it. Just I summarize in this slide the conclusion. We say there is a main conclusion is that we have to accelerate the sludge management towards sustainability it is necessary to approach the wastewater sludge management systems with respect for criteria of greater responsibility in social environmental and economic terms which are the sustainability without we are considering also the circular economy and the thermodynamic principle. From this point sludge management should be considered conceptually considered as the locomotive of the water cycle train because the most appropriate sequence to adopt for wastewater treatment is strongly driving by the sludge reuse disposal options are available in the specific local context. We need first to check which are the options to reuse or to dispose of the sludge and then we must go back as I told before to the treatment in the wastewater sludge in the wastewater systems. Second, we also to introduce some technical actions I meant at improving sustainability by maximizing recovery benefits instead of just disposal and this must be must be introduced this adopted these technical actions. I think this is my last slide I think I hope to have been in my times and thank you very much for your attendance Thank you. Thank you very much Professor Spinoza that's very interesting and stimulating presentation. We will have further discussions on your presentation towards the end so I see some questions already coming in please type a question in the Q&A using the Q&A box over there so now we will move into the second presentation by Miss Pooja Doshi Pooja. Yes and also welcome from my side I would like to proceed with the second part of our presentation which is about the structural aspects that help us to accelerate sludge management towards sustainability. Next slide please. To establish an innovative technology that leads wastewater and sludge management towards sustainability it is pivotal to enable the right institutional environment and remove environmental pluralism and the generous barriers are mostly related to social cultural or imminent factors that prevent for example that prevent people for example to recycle waste they mostly tie it to local economic political or cultural priorities and therefore one should address wastewater management in a highly contextualised context which should address wastewater management in a highly contextualised approach solutions regarding the system must be tailored according to the local needs and one needs to distinguish between rural peri-urban or urban areas that set aside specific circumstances such as climate soil quality level of groundwater table cultural aspects space etc Exogenous factors are mainly related to the economic access to public systems and include water poverty socially disadvantaged groups or low income households an example first I'll get to the third one legal pluralism so legal pluralism describes basically legal practices and norms that are not to be seen as monolithic entities but which are in fact multi-layered and subject to negotiation and enforcement and one can see a gap between rules and behaviour as a summary of what legal pluralism entails a possible solution or remedy for the exogenous factors could be to establish pricing mechanisms pricing mechanisms can support us in a three fold manner they can act as a fine tuning instruments for social aspects they can be a revenue raising they can be used as a revenue raising instrument covering operational and maintenance costs and with the polluter pays principle you can ensure long-time investment as a fine tuning instrument there is the example of the so-called block tariff system which was promoted by the World Bank in the 1970s it is a price structure in which a commodity, water, is priced at a very low initial rate up to a specified volume of use which is a block then at a higher or several increasing higher rates for additional blocks being used the price of water in the initial block is set very low usually at a rate to ensure that poor people are not discouraged from using the amount of water considered essential for human needs typically 25 to 50 litres per capita per day this results in higher marginal prices to the customer and thus higher average prices for higher income households but helps in discouraging extravagant extra wagon water use and promotes water conservation however the system could result in adverse effects because the assumption that every household owns a water meter does not reflect the reality in many developing countries where many households in higher densely populated area such as slums share one water meter perhaps this means that the marginal and average costs per water meter are automatically placed into a higher tariff system further many households do not have access to any sort of water meter so they're dependent on water vendors and this system results in adverse unintended effects in spite of the adverse effects nonetheless the system of the block tariff supports low level incomes low level income households to gain access to the wastewater system the third barrier is legal pluralism legal pluralism is characterised by the existence of rules from different origin and legitimisation for example as the result of history through colonialism this coexistence often leads to an overlap of customary laws, religious laws, national laws or even international principles derived from global water policy concepts the concept of legal pluralism also includes the distinction between categorical or official the euro rights and concrete or effective de facto rights the formal acceptance of law does not mean that law is really applied into practice obeying the law without complying with it can be seen as a reminiscence of colonial times the categorical right is embodied in the legal status whereas the concrete right is embodied into a social relationship between actual people and this concept helps us to understand why implementation and enforcement of existing regulation often seem to fail legal pluralism which refers basically to the lack of law enforcement and the existence of multiple layers and illegal or semi-legal systems within people within which people usually negotiate and make decisions the stickiness describes when formal institutions outlive their usefulness but are resilient to change or dissolution institutional dynamics can be addressed by choosing the right institutional path there are different paths that we can choose from and the first one would be the path dependency which again describes a certain stickiness to institutions so here historical or cultural traditions and policy legacies influence actual actions and tend not to adapt towards new circumstances an institutional means that new elements are simply mixed to traditional or local elements this possibly colliding modern ideas institutional syncretism combines the old and the new traditional and modern informal and formal elements which are interwoven in a creative process this forming a completely new type of institution the institutional syncretism is the right answer to the re-conceptualization of waste water treatment to continue old institutions under new conditions while acknowledging excuse me please endogenous which are embedded social norms and exogenous access barriers which we described as costs and poverty etc once the foundation has been laid by diminishing the barriers and a proper institutional environment has been created one can accelerate sludge management towards sustainability by introducing regulatory mechanisms these should bridge the gap of compliance with existing legislation provide capacity and resources to ensure implementation at the local or municipal level and force and follow up on existing legislation and strengthen the political will to do so update legislation and harmonize legislation change management change perception about waste and put society's interest above political interest by setting up the rules of the game accordingly furthermore regulation should be generic enough so it can be applied in different contexts alike yet be still specific enough to do the job and set up the right standards and have clear rules for penalties and sanctions regulation needs to be adapted to the local context an issue to avoid imposition of generic and not numerically quantified limits which may have general applicability and are different but are difficult to be widely applied and prosecuted and unjustified although numerically quantified limits which could become dangerous in certain situations the second step towards acceleration is to provide standardization the development of standardized characterization methods is a necessary support to the development of regulation since well-defined procedures allow legal requirements to be fulfilled in a correct and uniform manner thus building stakeholder and public confidence digitalization as a third pillar can support these objectives by providing features such as an app to communicate barrier free between citizens and the utilities thus again building stakeholder confidence but digitalization can be applied in three different fields first one is controlling energy consumption second one is reducing toxicity and the third one is to optimize sludge transportation it's very important to see that this digital concept is defined by system optimization above process optimization real-time data obtained by digital twins provide a firm information base on the quantity and characterization of sludge sludge wastewater treatment plans tend to be highly energy consumptive and are ranked as one of the most important energy consumers managed by municipalities real-time data again here can obtain can provide a firm information base on the quantity of sludge depending on the quantity that is produced on a daily or short term basis energy and chemical input for treatment can be regulated short term fluctuations for example seasonal ones in sludge production can thus be leveled out one of the foremost challenges in wastewater management is the diverse nature of contaminants of wastewater since different industries contribute different constituents to the wastewater with wastewater discharge from industries especially from chemical manufacturing it is important to ensure that the presence of toxic chemicals is below the specified concentration quality control becomes very important sensor technology is useful in both wastewater and sludge management and sensors can be used to analyze recovery worthy as well as toxic compounds quality control by integrating sensor technology with artificial intelligence allows for cost-defective safety measurement with quick results just reducing transaction costs where time consuming procedures through labs sludge management cannot be seen in a silo and involves the transportation towards its destination either as waste towards waste depot or landfill or second as a product or commodity for agricultural use or cement plants decision makers are enabled to get insights via the digital twin by knowing sludge for example by knowing the sludge destination and a conscious choice can be made in choosing the right treatment method and the right transportation mode please bear in mind again the concept of the locomotive which basically starts at the end at the sludge and this is basically what we try to say here that once we know what the final destination or what the destination of sludge should be one can accordingly treat sludge what kind of technology to use and to maximize the recovery value and for example for the minimized toxicity etc so yes so basically the three pillars I've introduced in my part are regulation standardization and digitalization and they basically accelerate sludge management towards sustainability yet in order for them to work it's very important that we create the right institutional environment by using the right path which we have defined as institutional syncretism and it's tremendously important to diminish or at least reduce the barriers which stop to create the right environment for the three pillars to stand on so yeah I think I've more or less basically said this so the most important part is basically to have to create the right institutional environment which is not just a legal job it's a political decision making it's the people who work for it and it's very very important to diminish the barriers which are like which can be endogenous by providing local solutions and very contextualized solutions basically tailor made solutions and respect the local variety way more important it is also to diminish exogenous barriers which are mostly cost related so that everybody can access to a proper wastewater system and one solution that we introduce in our concept is pricing mechanisms that basically target different aspects like supporting to find social aspects but also to ensure long term investment into the field of wastewater management second and third very important factors are the regulatory methods and standardization methods and also appropriate business models that makes large and attractive commodity including supply chain mechanisms towards the destination and also to incentivize the industry to produce fewer toxic compounds at the very basic level but also to introduce digitalization methods such as sensor technology to further allow us to get rid of the contaminants which are very complex in waste in wastewater and sludge and digitalization also allows us to obtain a greater operational capacity through real time monitoring and building also stakeholder confidence by reducing barriers between citizen and institutions for example through web applications yes thank you very much and yes Richard that's a very interesting aspect from the institution aspect as well that part of the consideration hasn't been looked at as much but yeah glad you brought those out so the remaining time we have time for questions and discussion with some of the points that have been presented so perhaps we'll start with the question that had come in I know that these couple of slides related to the conclusions are already being covered so I think we'll go to the Q&A this point, Ludovico both of you probably should turn your mic on and the video as well as we address Q&A please sorry but no it doesn't work the microphone is okay, the camera no okay it's a little slower that's it so anyway there is the first question is addressed to you Ludovico yes but as you said there is no problem the question is just two words the problem is not the only question of cost the cost is mainly related to the size of the plants the aerobic digestional stabilization is more adapted for small plant and aerobic for bigger plant which give also the possibility to recover energy but now there are many many new plants that couple anaerobic followed by aerobic mesophilic and this could be an optimization of the process so the question is talking about capex and op-ed comparison of aerobic stabilization you know so certainly totally agree Ludovico I think the size of the facility has a lot to do with that decision so but there are exceptions as well related to that and we can discuss it further later on if needed another question what can be done to in case a wastewater treatment plan is already operating and yet sludge management was not properly accounted for there are plenty of examples of that unfortunately and I will come up on that as in the case of an urban area where there is no land for possible heading the possible expansion to include sludge treatment processes so the question is not addressed to anybody specifically but Ludovico you want to start addressing that maybe to add something in the case I don't know it depends what is the size of the plant and everything and what is already available but in any case I think in the case when sludge there is not enough land for utilization in agriculture and the plant works to produce some sludge for agriculture that is the solution that allows to produce for example composting you can produce from the sludge some compost that can be commercialized elsewhere in other places so sludge is difficult to be transported but compost could be in some bags and you can transfer everything this is just one example of the possibility it should be necessary to have more more other in the case in the following questions just the same where there is no land for possible expansion I don't know I cannot respond I hope that can be I hope that will be possible in the vicinity of the plant is possible to have enough space for building a composting plant to which sludge can be can be send for example together with other organic waste solid waste or agricultural organic waste just to produce a compost of good quality for example this could be I guess I'll add to that so certainly there is no space you are all luck you can't add any treatment processes on site so offsite consideration I think compost as a little indicated could be an option but I think you know potentially look at other treatment plants that the system may have I guess your location specific location in what it is sounds like it's an urban area it's an urban area maybe you already have a collection system there so you can look into how to transport or convey the sludge to other places offsite either for a dedicated sludge management site for treatment or another treatment plan that the utility may own that has space for treatment as well you know so we centralizing solid treatment is not uncommon so that can be done if it's available so I think you're you doubt it those option under this particular scenario but certainly isn't uncommon we have seen a lot of plans that have not planned on sludge management as your question if I can add something the question of realizing centralized plant could be a possibility but in the case that the plant must be very close each other and small in practice but there is the contrary for example in the case of for the watering there are some experiences in which a machine for the watering is mounted on a truck and this machine could be too big for a single plant because they are very small plants so it goes every day to another plant to dewater the sludge of the other plant is the contrary of the centralized plant in which this works okay let's move to the next question so this one's on Pujo and the question is is there any example that can be cited concerning the needed institutional syncretism that you mentioned maybe some experience already in place yes sure so for example there is one would be it's called the Keist of Wirtschaftskazette which has been established in Germany like 10 years ago so which basically incorporate the idea of circular economy so that would be one example another example would be the law for water more or less in South Africa they basically try to use the idea of water as being integrated as being an integrated system so they don't look at water anymore through an administrative lens but see all water resources as natural basins like where you could say they included a holistic approach and there is a lot of approaches like that coming up India also around 10 years ago established a new national water policy that one has incorporated a lot of aspects concerning cultural factors and socio-economical factors but also like local technology local knowledge basically to provide a bottom approach when it comes to water management so there is definitely a switch between what is happening yet I suppose there is way more work to be done especially considering aspects when it comes to addressing the gaps between what is the law what is the legal status and what is the actual behaviour of people and also providing them with the right motive but also the right resources so they can bridge that gap thank you so there is another question from if you are asking about case studies or success stories can you be a little bit more specific in sending in the question if you are talking about case study or success stories is it related to a certain aspect of sludge management so maybe we will wait for clarification for the question here let me move down to another question do you think EU in recent future will introduce the use of waste sludge or sewage to feed insects which are then used as fish stock for fish or for cattle thus to reduce the impact of cattle but also to implement a new way of considering this sludge I have no information about this approach so I am sorry I cannot answer that question but I think it is very interesting so I have not heard that we try to use waste sludge directly to feed insects I guess the closest thing I have seen is vermicomposting I guess they have these worms to help compost and stabilize the sludge but I am not sure that they use the worm to feed livestock either but certainly interesting thought and I think this sludge can be treated or stabilized adequately so the impact of potential contaminants in there can be addressed I think that certainly a potential additional way of using the material in the future Ludo, what do you think? Do you have any thoughts on this? I am a mechanical engineer so for me it is quite difficult to speak about toxic pollutants for feeding worms I don't know but my personal opinion is that there are so many possibilities to use the sludge I think that we could leave this just as the left if nothing else is possible to do this like the recirculation for example of water, the water from wastewater plant after treatment can be also used for drinking water to obtain drinking water to provide the best some better sources and to leave the water from plants for many other uses agricultural, industrial and so on this is my general concept but if you like Richard I wish just to make to the colleague that asked about studies or success stories I just would like to remember that show clearly what was done some years ago possibly 10 years ago I visited the plant in which the use of sludge was used in agriculture and for dewatering they used some belt presses and that produced the sludge the final concentration the solid concentration of this sludge after belt pressing was of 20% about 20% but to send, to distribute on land, to spread on land this sludge they had to add water to reach 15% so they first dewatered and then rewatered again I said ok it is so easy to do it 20% another part leave as it is 10% after thickening or 6% and then put together and you spend a lot of money less this typical story of unsuccess I've got a clarification of the case study that they're asking for this process do you have anything to add? well there are in this last there are in development many other plants working on the carbonisation the gasification and so on but as far as I know these are not not convenient from a full size plant they are only a little bit more experimental so there will be some other times more times to really obtain the good result what is important to say for example one of the technologies that is developed in the last period let me check is the development of full cell to produce electricity from sludge during full cell this is a very promising but still not on full scale available so when you refer to decarbonisation I assume you're talking about reducing the carbon footprint of the processing so I think there are quite a few good examples out there that are successful in terms of doing that a number of plants have been able to extract energy from solid processing one way to do that and by extracting biogas reusing the biogas and in a way to sustain the processes I have also seen some thermal processes that were very close to circular in terms of processing again dewater the solids and first dry the solids and then pyrolysis process to decompose the sludge and then extract the thermal energy through the pyrolysis process and utilizing that energy to sustain the thermal drying process so the energy is fairly close in terms of being circular so certainly that reduces the overall carbon footprint if you're comparing to strictly dewatering the material then transport it out to some other sites for other disposal and options that are cited for that so let me move to another question I think we have a few others do you have success experience to share about digitization in FICO sludge collection system who would like is again is not addressed specifically to a presenter Ludo or Pooja do you have something to share with certain companies to use digital methods when it comes for example to chemical input and also to basically what I mentioned to sort of regulate the chemical input towards the necessity which is relevant to the quantity the question is specifically about application for FICO sludge collection system all right okay so I do not have any example on my hand I'm not only that either Ludo do you have anything to share sorry we don't have any any example that we can share in that regard but composting and shoe sludge disinfection used in a cultural for example how can we enhance the composting process to reach sludge disinfection I can try to address that but Ludo are you still with us maybe maybe he's having audio difficulty so let me let me address that so the question the answer is yes composting can effectively disinfect the sludge but the operation need to be control adequately so the way to disinfect it it's through the heat generated in composting so you can maintain first of all have operating conditions and that can reach sufficient temperature people who have done composting know depending on how hot you can maintain that pile obviously it's function of how you prepare the mix, what kind of fish stock you have and so on and so forth but if you can adequately address that and ensure the temperature is adequately the required disinfection temperature is rich during your process then I think you can be successful in doing so in any case I think that the use of word disinfection is not correct for compost I think that sanitification should be better because a real disinfection are required should be in any case just well yeah good point so you in composting well so disinfection I guess somebody has to define what that really means but we're not pasteurizing the sludge right in composting you're not killing everything that's in it but it can for example in the US we can have a compost that is adequately meeting a class A pathogen reduction requirement for example I think you can find a similar European standard for that so that is reducing substantially the pathogen level in the finished compost you know to me is adequately disinfecting it to the acceptable level for use so hopefully that answers your question adequately but you also to think you spoke about states that's true but you consider also the developing countries where these conditions are difficult to be obtained yeah yeah that's our next question actually is so a fairly general question any advice for a small island developing states with our land space what options may be available to them Ludo you want to pick that or Pooja you can try I think that the problem is that how small is the islands and which kind of space you need in some islands of the Maldives you have the small islands where there is a hotel a hotel a CSN hotel they use the incinerator in practice and they recover the energy to feed all the systems but this could be an idea but this is in case for very small plants in case you have a big space you can have a better plant not incinerator, not thermal processes but you can have a normal process but you have not space for using sludge you can make the question of composting that we said before you can produce compost and commercialize it in the surrounding countries could be an hypothesis but it's necessary to see case by case yeah it's certainly agree with that it's you know very very challenging when we don't have space and you're also in a place that high tech approach may not be appropriate because usually the low tech treatment requires space and if you don't have the space you need to be looking a high rate type of system and that typically require a more advanced type of treatment or you need to be looking for a solution that does not generate a lot of end product or residue so if you don't have land to use it and you're on an island which means transporting it offside would be difficult I see another question for me if there is any new technology that can drive sludge to 35% moisture from 65% moisture coming from centrifugal the watering process I think that in this case only some something drying by thermal by heat should be possible because you can use filter press but feeding a filter press with sludge having already 65% of moisture it means 35 solids is difficult to feed and to work so probably in this case only some dryer could be enough could be necessary to improve the solids concentration this is my opinion I don't know if it's personal but yeah I'll add a little bit to that so yeah 35% moisture is fairly low for sludge cake so without thermal drying I think there are a number of factors first of all what's in your sludge what kind of sludge are we talking about and you know the only thing that I can that I have seen through my career that came close to that and I'm not saying exactly at 65 but anything that can reach beyond 50% so dry content will require some kind of pretreatment to your sludge especially when biological sludge is part of it and you know so the processes like what what oxidation thermal hydrolysis those type of pretreatment tend to improve the waterability of the sludge quite a bit and changes to the viscosity as well so that they tend to improve dewatering whether or not it will hit 65% dryness it's questionable I think is a function of how what the makeup of your sludge is you know if it's a dredge material you will get that but if it's a typical municipal sludge I think it will be quite challenging to try to achieve that just a comment why I don't like to put two processes in line as in sequence to obtain this one it's better to eliminate the first one and produce the second one from the beginning to 35 solids through a dryer why using two processes it's a complication I think okay we've got another question here technology is only part of the solution how the system are operating and maintaining access to FSM I would be interested in hearing about regulations and standardization from Pooja that have worked to ensure the poorest are able to access safely managed sanitation services such as emptying and that also ensure proper operation of treatment facility so Pooja this is yours yes so well I am sort of a little bit where I cannot really give you good examples for it I have more negative examples than positive examples like one example I tried to state in my presentation was that of the World Bank where one has tried to incentivise people with the pricing mechanism now when it comes to regulations and standardization I do not really have a body of work that gives me that sort of information I feel that a lot has been done in the last 10 years I think last 10 to 15 years but perhaps we need to wait for the results to actually to be seen so I must really say I am sorry I don't have examples at my hand but I think that is going to be homework for me I cannot do something in this field because as I am part of the standardization activities at CEN European Committee for Standardization and ISO just to remain in mind that there are in both programs in both institutions two specific projects or technical committee devoted to large standardization and in particular it is the ISO TC-275 and ISO and CEN TC-308 and within this technical committee all the all the standards relevant technological, chemical, biological and so on are standardizes just to guarantee that uniformity and comparison a reliable comparison between results obtained in different results so you can check if in the project I mentioned you can check there are a lot of studies of reports of standards and so on also in the field of safety well perhaps what I can say is that I mean there are a lot of small projects like where one introduces sort of proper sanitation systems which also have sort of on-site management of fissiles, sludge and composting methods and all of that but it's like those are like sort of bottom approaches and rather very small scale and very localized like for example the water policy in India they sort of promote these sort of projects but I think that's it has nothing really to do with a wide regulatory process in this case so this is basically those are like sort of small scale solutions, bottom up solutions that are sort of important by the nation states and developing countries but it's not like a nationwide regulation as such yeah. Okay thank you next question is addressed to both presenters the question is about any experience situation where the sludge from a water treatment plan is classified as schedule ways due to the usage of alumus coagulant then what option do we have to reuse the sludge? Okay I can say that this depends from the national legislation regulation each regulation has some limits for metals or some other materials in the sludge for the reuse so it's difficult to say in Europe for example there are some, there is a general limits fixed by the European Union and then each state can fix stranger, more stringent limits for use in their own country and yes there are also they cannot say anything else it depends from the local regulations Pooja do you have anything to add on this? On this one particularly no Okay Thank you I think that was not the question I have there's a comment edited about solid content can reach up to 80% yes definitely can do actually thermal drying can dry to any dryness that you desire if you allow enough time for it to do that but if you're referring to the discussion we have early on regarding the 65% dryness I think that question was specifically related to a dewatering process not a thermal drying process so we will be referring to a mechanical dewatering process okay I think that's the end of the list oh actually there were a couple that came in on the chat let me see if I missed anything here I was hoping to one comment here was hoping to hear of options for sludge management for sets which do not have space as ideas what's that we're going to Pooja and where do you read this question it's from the chat they should have put it in Q&A from the chat okay okay okay yeah but I'm not sure what sets is could you perhaps repeat the question I was hoping to hear of options for sludge management for sets as ideas which do not have space oh okay so like in terms of the sludge destination like landfill or regarding space in which context yeah I'm not sure I can interpret it adequately I don't see what is the question well if it's I was hoping to hear option for sludge management for SEDS this one okay this is small islands this is the abbreviation of small islands well I mean one could transport sludge like through pipelines or through other modes I mean through shipping but that is sort of that would make sense if you would have basically a proper economic structure and then you could really say okay these people they need sort of that sludge I mean if you have the example of malletives you could say that malletives could export a sludge to a neighboring country if it makes sense it would be possible if you would treat sludge as a commodity and if you could provide the right quantity then it is possible also to bring in different modes of transportation such as pipelines or ships or trucks is perhaps difficult when it's an island but yes and their regulation can also help and if you regulate it in a manner that you're basically allowed to transport sludge over a long distance very often that is not the case or that's not possible so it really depends also on that but I feel for small islands which don't have space for land filling I think first and foremost it would be great perhaps to produce as less sludge as possible and perhaps small islands shouldn't have big industrial complexes or that much of dense population so anyway not much of sludge is produced and that bit of sludge that is produced it could be composted immediately there shouldn't be any toxic elements involved so perhaps there is not even a necessity to for land filling these would be the two options transportation over a longer distance and basically not creating any sludge that needs land filling but just composting as organic as possible yes I agree with you as I told before the same but just as better to remind that in case of transporting sludge this is the case in which the volume of the sludge must be reduced as much as possible because especially if you go to shipping or to use some pipelines or so it depends okay in this lab so I want to thank our presenters and also just take a minute to conclude a very interesting aspect on sludge management it's still very challenging we try to address the technical aspect and the institution aspect and certainly sludge management need to be the driving force in a lot of these planning efforts not trusty and as an afterthought I find it very interesting that Ludovico kind of characterized the two aspects of technical nuisance reduction and volume reduction but a very practical certainly is true that we've been working on those very closely but I think the aspect you know related to the quality of the resulting residual is also very important to be able to use the material adequately sort of that sort of address a little bit under the institution aspect as Pooja discussed the quality of the lack of toxicity of toxic compounds in the product so that's very important certainly from the institution aspect regulation has as a big influence on what can be done understand that the EU is considering revising some of those directive in the next year or so so we would be very interested in looking at what comes that way so with that again thank you Dr. Spinoza and Pooja to present at this seminar and I appreciate everybody who participated so with that let's move towards the end you know there are a couple of upcoming webinar if you're interested in the details here and also IWA is actively recruiting new members so you can use the code to get 20% off so with that thank you again and goodbye thank you very much goodbye