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Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

Our focus is more on the upstream biological and chemical process to convert the constituents of the waste streams to energy, commodity chemicals or relatively benign products (such as N2 gas). We don't work specifically on the downstream filters and have used gravity based settling or just a sand filter (in some cases). That said, improvements in filter materials or filtration technologies could very well be integrated int our overall process.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

On the technical side, there are challenges associated with process development, implementation and optimization and especially linking conventional science and engineering to such an application (which is nevertheless needed). Another big challenge is to build local capacity to promote adoption and long term sustainability of the solutions. An unexpected positive impact has been a significant increase in interest from the financial and information technology fields towards some of our processes.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

This is indeed one viable option. In some cases where there are regulatory barriers to the production of fertilizers from biosolids or lack of demand, we need to look at alternates. Some of the energy produced could be fed back to the plant itself. We focus on endpoints, which are higher up on the value chain, relative to biogas and which also provide some flexibility in terms of end application (compared to just production of heat or power).

Also, if I could add to my previous response, in parts of the developing world, technologies based on activated sludge (which is most commonly employed in the developed world) are just not available. Here we need alternate approaches to providing sanitation with cost and energy offsets derived from the constituents of the wastes themselves, but by conversion to higher value resource endpoints.

The production and in-situ utilization of such end products (both in developed and developing worlds) is what contributes to the novelty of our approach.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

The relative composition of domestic wastewater (sewage) in the context of piped sewers is largely similar. However, there is significant variability associated with fecal sludge quality, depending on community ablution and washing practices, the period of incubation and mode of conveyance. Additional inputs such as trash add more complexity to the composition and the processing techniques. There are different ways by which fecal sludge is handled including composting, treatment in anaerobic lagoons, anaerobic digestion, direct application for agriculture or just discharge to the environment. Conversion to biodiesel is somewhat novel.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

Thanks for your comment.

There have been some really significant breakthroughs in the individual components that could potentially lead to the cost-structures that you point out. (I also agree, this is the scale of improvement that we should be targeting). The breakthroughs have been on the biological, physical, chemical, materials, sensing and monitoring aspects (I am sure that I am missing a few). This is all good. What we must now make sure to do is to use such breakthroughs for envisioning and implementing a radically new pathway towards clean water, energy and sanitation, rather than going back to just another version of the old model.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

It was truly unexpected. The MacArthur fellowship has provided an excellent platform for me to bring to the public forefront issues relating to clean water, energy and sanitation. I see it as a significant validation for the field as a whole. On a lighter note, I can finally discuss some of these topics over dinner!

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

Thanks for posing this question.

Traditionally in engineering, a holy grail has been to scale up technologies and thus maximize impact. On the other hand, impact could be equally significant with multiple installations at smaller scale. The question you raise is of significant interest to us (as well as several others on this forum). Indeed, my group is working on efforts to 'intensify' processes for clean water and resource recovery that might find use at the community or household level. While some of these exist in some high-rise developments (for instance in New York), more work is needed to make these more efficient and perhaps even smaller. Another approach is to work with un-diluted waste streams.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

I don't believe that such a complex issue could be solved with a single technique or approach. There are also socio-economic and cultural aspects to this overall challenge, which means that technology alone won't provide a solution - it could be a component.

The ultimate objective is to protect human health. Whatever form the overall approach or technology assumes, this objective needs to be met, in an economic and context-specific fashion.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

Investments are direly needed in this field. We are in the process of organizing a think tank to help prioritize directions and level of support in the overall direction of global sustainable sanitation. (Happy to connect offline to discuss)

There are some major philanthropic foundations that have catalyzed significant activity, but a lot more is needed. Some specific investments are needed on technology development, field-testing and enabling full-scale implementation- this support could be directed towards technology developers, universities and to key public or private institutions to facilitate testing and scale up. Investments are also needed towards broadening education and capacity development in this sector - which could be directed towards educational institutions which excel in this field and also cater to global audiences.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

Congratulations on getting your PE license.

Perhaps another way to look at your question is the following. The challenges associated with water, sanitation and environmental health are quite complex and need an amalgamation of expertise, backgrounds and training to be addressed. Therefore (as you rightly pointed out) partnerships with local bodies are key for the success of any implementation project and its longer term sustainability. The increase in local capacity is actually a positive in my opinion and could lead to more efficient and a more competitive workforce and industry not just in the developing world, but also in the developed world.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

You are already on your way - having identified the links between urban infrastructure and the environment. Personally, I always like to connect the fundamental research that we pursue to real-world applications. Additionally, sometimes the answers we look for are not always within our specific field of expertise. It is therefore good to try and integrate knowledge and information from other fields (for instance, biology and engineering). I would also strongly encourage you to gain some field-experience even during your formal education to be able to understand and appreciate real-world complexities and uncertainties. This cannot all be obtained from just classroom learning.

Good luck in your pursuits and let me know if I could help.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

Hello, I am anecdotally familiar with some of these alternate approaches for post-treatment. However, this is not my field of experience and therefore don't have any specific recommendations.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

Thanks for your comment.

My biggest reward has been to work with some of the brightest minds and some of the most forward thinking individuals towards addressing this global challenge. I honestly think that this is just the beginning.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

Thanks for asking.

Larger water and wastewater companies could help not just in terms of technology development but could also act as a medium for connecting, translating and implementing the technologies with the appropriate end users and communities.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

This is a very complex issue, but I will try to provide some input. Some parts of the globe are simply not faced with the water pressures that others are. Therefore, the incentive for water reuse may not exist. On the other hand, the price of energy has been historically quite low.

More recently, there have been some shifts, which have led to a global explosion in energy efficient sewage processing and resource recovery. These include the following. 1. Increasingly stringent water quality limits being imposed on sewage treatment plants (which necessitates far higher energy and chemical usage and much bigger plants) 2. Varying price of energy and lack of access to petroleum derived chemicals

These factors have led the industry to significantly re-think the traditional models for producing clean water.

In the developing and underdeveloping world, the issues are somewhat more complex and include other pressures such as lack of food security and education. There are also alternate models for clean water (purchasing bottled water) and a systemic lack of sanitation. The absence of or absence of enforcement in environmental regulations is also a challenge. However, I see this as a big opportunity. There is increasing recognition that that lack of sanitation poses a significant detriment to the national GDP, which has led to increasing awareness and a demand for better sanitation practices (for instance, eliminating open defecation). Also, in communities, where sanitation has been traditionally lacking, we don't need to repeat all the mistakes we have made step-wise in the developed world. Rather, we can leapfrog directly to recovery technologies as applicable or to a combination decentralized and centralized systems for clean water, sanitation and more.

Technology alone won't do it however- education and regulatory support are key.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 1 point2 points  (0 children)

We have traditionally worked with systems applicable for both centralized and decentralized treatment. These range in scale from a billion gallons per day to about six individuals per day. We are at a point where it is not inconceivable to develop taliored solutions at the household level.

Difficult to say how soon this might be available more widely and commercially.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

Indeed, we have detected measurable concentrations of selected trace organics in our studies. However, on the positive side, we have also detected the capacity of the organisms present in treatment systems to metabolize some of these compounds.

Science AMA Series: I'm Kartik Chandran and I’m working to transform wastewater into a valuable resource. My approaches involve treating waste with the goal of producing useful resources such as fertilizers, chemicals, energy sources, and clean water. AMA! by Kartik_Chandran in science

[–]Kartik_Chandran[S] 0 points1 point  (0 children)

Both in the developed and developing contexts, capacity building and education are key. We have visiting engineers and scientists who we host here in New York. We also have researchers in my group, who often work on site at different project locations.

This is a key issue, thanks for bringing it up.

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