Nature-based Drinking Water Filters

Waterborne diseases like diarrhea, cholera, and typhoid are a serious public health issue, causing 3.4 million deaths annually. Excess rainfall, flooding, and higher temperatures caused by climate change exacerbates these issues, with outbreaks of waterborne diseases affecting hundreds of thousands of people. Over 30 million people are affected by floods every year, and 23.7 million people were displaced by disasters in 2021. According to the World Meteorological Organization (2021), flood-related disasters have increased by 134% since 2000, and such incidents are expected to get worse with climate change. These issues affect developing as well as developed countries, but limited infrastructure and resources in developing countries cause greater devastating impact.

Due to contamination of/damage to infrastructure, provision of clean drinking water is critical to mitigate the spread of waterborne diseases after disasters such as floods. Rapid response in the direct aftermath of flooding (before community-level infrastructure can be set up) often involves distribution of packaged or bottled water, but the sheer weight and volume of water involved and damage or flooding of roads makes it difficult. Boiling or water purification tablets may be used, yet the former requires fuel, and the latter is not effective against protozoa, typically does not remove turbidity or chemicals, can generate harmful byproducts, and suffers from issues of poor taste and social acceptance. Current commercial point-of-use water filters are typically expensive (e.g. $30 or more), making it difficult to reach millions of people in need. As a consequence, inexpensive, scalable, and rapidly deployable solutions to provide clean drinking water immediately after floods are needed. 

We have developed a patent-pending (PCT/US2022/076211) low-cost, sustainable and biodegradable filter with a short use life (<1 week), which builds upon extensive research, stakeholder feedback, and field validation at MIT. Our technology utilizes the xylem tissue of plants that is responsible for the flow of sap from the roots to the leaves. In 2014, one of our founders (Dr. Rohit Karnik and collaborators at MIT) showed that the xylem tissue present in the sapwood of conifers (such as pine trees) can be used to filter water. Further development, including human-centered design, led to foundational understanding and designing of water filters based on xylem tissue in wood, with third-party tests showing the ability to meet ‘Comprehensive Protection’ standard for microbial protection as per WHO. Our wood filters are the size of credit cards (e.g., 5x5x10 cm3), which we aim to package to patent-pending biodegradable foldable filters that fit in a wallet-sized pouch, weigh ~100 g, cost ~$1, and provide 10-50 L of clean drinking water in 2-3 days. 

The sapwood is the low-grade byproduct of the wood industry (i.e., branches and peripheral wood), which is commonly discarded, and is available in very large volumes at little to no cost. The global timber production exceeds 1 billion m3, but just 10,000 m3 (< 0.001%) is sufficient to make up to 500 million xylem filters. We have recently established a scalable wood waste source (sapwood of eastern white pine), and fabricated filters showing ~log(3) rejection of E. coli as tested by a third party lab. Depictions of a filter using innovative slotting (for faster flow) and without slotting can be seen below:

Beyond disaster relief, the ability to create filters from different gymnosperms, widespread availability of gymnosperm xylem, low cost, natural appeal, ease of transport and distribution, and the traditional comfort associated with wood, will help DetoXiFy’s filters lower the barriers of access, affordability, and social acceptance, and thereby facilitate access to safe drinking water especially to rural and indigenous people in the US and around the world.

Within the initial market of disaster relief, there are no other filtration technologies that can provide similar features (low cost, rapidly deployable, biodegradable, highly effective at removing all contaminants, and sustainable). The main alternatives are boiling (requires fuel), bottled/packaged water (costly, difficult to deploy quickly due to large weight and volume) and water purification tablets/chlorination (not effective against some protozoa, does not remove turbidity or chemicals, can generate harmful byproducts, issues of taste and social acceptance, requires measured dosing if using bulk chlorinating agents). Compared to other commercial filters, retail filters (e.g. Brita) that could serve as interventions, our technology would provide comprehensive protection, health benefits, at a fraction of the cost, enabling disaster relief agencies to stock and distribute 2.5x more units reaching more people for the same capital costs. Compared to plastic water bottles, our filters would be 1/100th of the weight, making it possible to transport via air where transport over land may be difficult or impossible. 

Our intended reach is for humanitarian relief where we can reliably provide potable water via a compact, lightweight, foldable and biodegradable  filter for the first several days after the immediate occurrence of disaster (focusing on, but not limited to floods), and before infrastructure for longer-term solutions can be put into place. The target demographic includes mainly low-income rural or semi-urban communities in developing countries across the world impacted by flooding, or rural, low-income communities (including first nations communities) impacted by flooding in the US and other developed countries. 

In the US for instance, 77 million people can be affected per year with access to water from sources which violate safety standards because of disasters or other infrastructural issues. We see the greatest impact in the southwest and southcentral parts of the US where high social vulnerability, particularly along race and ethnicity, exacerbates issues surrounding access to clean drinking water. We hope our affordable solutions shifts power back into the hands of the people.

During development of this technology and scaleup, the filter in different form factors were tested across thousands of people in rural India (see images below), Uganda, Madagascar, and the US and was well accepted by the community given the naturality, efficacy, and ease of use. We also have interested humanitarian organisations wanting to work with us given that we can get this funding to build devices. We envision reaching our target demographic via NGOs and other agencies working on disaster relief.

We have received verbal and in writing interest from various humanitarian and relief organisations. These include, DRIIV (India) for large scale pilot and written email chains as well, verbal interest from Water Aid (India) for large scale pilot and written email chains as well 2) Verbal interest from Piramal Sarvajal Foundation (India) for pilot and written email chains as well 3) Verbal interest from Samaritan’s Purse (faith based organization) to pilot and field test.

The team lead has lived in India his entire life and personally faced the effects of unclean drinking water. All three co-founders have. We have been a part of those communities and want to give power back to the people by providing affordable filters they can use.

DetoXyFi has partnered with Sawmills in Massachusetts and has demonstrated the ability to procure sapwood to meet the requirements of disaster relief deployment. Our manufacturing partner's portfolio includes a wide variety of public and private clients.

We have developed and tested our filters in multiple developing countries. This was done in combination with on-ground NGOs and through Prof Rohit Karnik's (co-founder) collaborators on the ground. For instance, in India the filters were tested using natural water in Uttarakhand, and user-centered studies were performed in Uttarakhand, Delhi, and Bengaluru. We now have support from DRIIV, WaterAid, Piramal Sarvajal etc to not just test but also deploy on a paid basis. 

Dhananjay Goel is a graduate of the Indian Institute of Technology (IIT) and is currently a joint degree student at HKS/Wharton. He has successfully built and commercialized a profitable fintech startup in India (Timble), is well connected within the startup ecosystem and helps with sales outreach and strategy. 

Rishon Benjamin is a graduate of MIT and HBS. He has successfully assisted medical device companies scale innovations in the dental and clinical spaces. Most recently, his extensive experience managing supply chains for a global firm will allow DetoXyFi to optimize production/sourcing. 

Prof. Rohit Karnik is the Tata Professor at MIT, and a globally recognized leader in research in micro/nanoscale fluidic systems with applications in water, healthcare, energy, and environment. He has co-authored about 100 journal papers and is co-inventor on over 25 patents or patent applications. Among other honors, he is recipient of the National Science Foundation CAREER Award and the US Department of Energy Early Career award. 

All three co-founders have personally suffered the effects of unclean drinking water and also bring their lived experience to the table. 

We have a functional prototype (pictures below) which can filter a few litres of water per hour. It can last for a few weeks and is completely collapsible. The filter expands into an hour glass shape into which you can put water at the top and the filtered water will come out from the bottom. The filtered water can be had as is or stored in any container by the household. The wood cylinder at the centre is the filter. Once completely used (current lifespan is around 50 litres of water filtered) it stops working. Through SOLVE we can work to increase the lifespan of the filter. Once used, you can pop the filter out and pop in a new filter.

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For the disaster relief market, DetoXyFi is currently in conversations with 4 different humanitarian organizations which have expressed a willingness to buy. These organizations usually stock and purchase 30K+ units every month at $25/filter. We can reduce their cost by 60% while providing them similar if not better levels of performance, particularly in removing contaminants. Our supply chain partners are ready to begin manufacturing contingent on making capital available. To breakeven, DetoXyFi would need to secure three months worth of orders from a single agency. Breaking even quickly, allows us to fund development of the next device design that can provide continued protection for communities affected by natural disasters post the first few weeks.

Through SOLVE we hope to become a part of a community whose core interest, a passion on which they thrive, is to build big bold solutions to solve the world's biggest problems. I hope through SOLVE we can build better filters— easier to use, longer lifespan, more robust at removing even more contaminants. I also hope through SOLVE we can connect with and provide humanitarian agencies and people across the world affected by disasters the filters they need NOW. 

Finally, an initial marketing and outreach campaign for a month via Google, Facebook, and Instagram has resulted in over 100 signups across 20 countries. The competition grant money, if made available, would put us in a comfortable position to start production soon and also build connections across countries and communities so that we can get these filters out to millions displaced and affected by disasters every year.

We also seek to leverage the MIT ecosystem to identify humanitarian organisations that we could partner with as well as product designers to help design a more user friendly product for our customers. 

At DetoXyFi, we develop and commercialize low-cost, compact, light-weight, effective, and rapidly deployable filters to provide clean drinking water to communities struggling with access to clean drinking water. Our filters are natural and made of engineered waste wood as a functional material, offering unique advantages of sustainability, low cost, biodegradability, and social acceptance (filters were developed with user input from disadvantaged communities). To build community resilience and address the general clean drinking water crisis, starting with disaster relief as a key application with potential for large humanitarian impact, we envision bringing a range of products such as light-weight collapsible filters and household filters with fully bio-based replaceables that remove physical, chemical, and biological contaminants. DetoXyFi is committed to improving affordability and access to clean drinking water for socioeconomically disadvantaged communities under adverse and normal conditions. There are four key capabilities that allow us to retain a competitive advantage:

Ability to selectively tackle contaminants: In addition to removing all contaminants that commercially available filters target, DetoXyFi filters can be eliminate disease causing agencys (bacteria, viruses, protozoa) and can be coupled with other natural sorbents to provide enhanced targeted protection against contaminants in specific geographies (e.g Arsenic in India or Lead in Flint, Michigan). Our filters can also tackle contaminants that other filters cannot, such as bacteria viruses and protozoa. A more detailed chart of this is attached below for your reference.

Readily available raw materials: A mere fraction (less than 0.1%) of the world’s timber waste annually can be transformed into millions of filters. This allows for the ability to produce filters for nearly everyone that needs it with very little burden to the environment.

Cost: We can provide filters at a fraction of the cost of our competitors. In the case of disaster relief, competition can also take the shape of alternative methods. A snapshot of that has been attached below for your reference.

Scalable forms and sizes: Our filtration platform can be sized, shaped, and modified to accommodate different use cases (community, single use, individual use, field use etc.) thereby lending itself as a platform for filtration.

This chart should help provide insight into the proposed costs and benefits that we can achieve (and a comparison with competition) in comparison to other commercially available filters, for when we attempt to enter the household market.

Our impact measures are:

• Increased ability of NGOs and governments to provide clean drinking water in the immediate aftermath of flood disasters; this will be validated in close collaboration with partners

• Increasing number of engagements with disaster relief organizations

• Reduction in waterborne illnesses upon distribution and use of DetoXyFi filters, via randomized control trials

• In addition to immediate intervention, we will equip communities with such filters in advance to proactively prepare them for emergency situations

The proposed product is based on 12 years of research at MIT, including elucidation of engineering principles to design filters based on wood, extensive characterization, validation of microbiological rejection performance by third-party labs, stakeholder studies, and human-centered design approaches. Detailed cost estimates place small wood filters at <10 cents. Commercially, 5 L water bags are available below $1. In addition to the Ford Fund, DetoXyFi is in conversation with with WaterAid, DRIIV, Water.org, and Piramal Sarvajal for larger scale pilots in semi-urban and rural India.

Immediate project outcomes:

1. Fabrication and lab validation of filters with synthetic challenge waters to meet desired specifications (filtration rate, volume, microbiological removal, filter size/weight).

2. Validation of product utility by field testing (user-friendliness, filtration performance) and via teams at NGOs working on disaster relief.

Longer-term:

1. Endorsement and uptake of product by NGOs, UN agencies, and governments, and its successful use in flood and other disasters (number of filters distributed and used).

2. After uptake by NGOs and agencies, measuring the impact of the product via metrics such as the number of people provided with drinking water in a given disaster by an NGO, compared to the number that would have been reached in the same situation in the absence of the product.

3. Randomized control trials (if possible) on the impact of providing the product and the incidence of waterborne disease. 

4. Leverage scale and learnings from disaster relief application to develop next gen water filters capable of reaching audiences needing longer-term use.

5. Development and uptake of wood-based filters for household water treatment.

DetoXyFi has developed a patented innovation that relies on wood as the raw material to create low cost, fully sustainable water filtration devices that provides a low cost, fully sustainable, water filter that provides protection against BOTH inorganic pollutants (salts, heavy metals etc.) AND organic pollutants (such as bacteria). DetoXyFi’s sustainable water filter uses reclaimed timberwood and transforms it into sustainable water filters. We do this through a proprietary chemical process which has been developed at MIT for over 12 years by Prof. Rohit Karnik. The technology, as an overview, utilizes the properties of xylem tissues present in plant stems (which enable transport of water in plants). We also make  use of rejected coconut husk in our manufacturing process. Through this, we have been able to create water filters that exceed WHO purification expectations and is able to filter out chemicals, metals (such as arsenic and lead), microplastics, and pathogens (virus, bacteria, protozoa) – unparalleled by any existing commercial solution. 

We are developing a chemical-free, low-cost, gravity-driven water filter based on naturally occurring xylem tissue in plants. The xylem tissue is responsible for the flow of sap from the roots to the leaves. In 2014, oneof our team members (Dr. Rohit Karnik and collaborators at MIT) showed that the xylem present in the sapwood of conifers has membranes can be used to filter water. The sapwood is the low-grade byproduct of the wood industry (i.e., branches and peripheral wood) and is available in very large volumes. The ability to create filters from different gymnosperms, widespread availability of gymnosperm xylem low cost, natural appeal, ease of transport and distribution, and the traditional comfort associated with wood, could help xylem filters lower the barriers of access, affordability, and social acceptance, and thereby facilitate access to safe drinking water.

Preliminary Data: Results of our initial testing demonstrated the microbiological performance of the filter. To assess the potential health impact of xylem filters and their effectiveness in reducing the risk of diarrheal diseases, we tested the filters’ ability to remove E. coli, MS-2 phage, and rotavirus (the single largest causal organism of diarrhea) from water. Xylem filters (4-cm diameter, 0.375-inch thickness, stored for 2 years, no pre-filtration) made from ginkgo were operated under a 1.2-m gravity head with GTW containing WHO- prescribed concentrations of E. coli (≥106 CFU/mL) and MS-2 phage (≥105 PFU/mL)37 and NSF-prescribed concentrations of rotavirus (≥104 PFU/mL).  E. coli and MS-2 phage were dosed simultaneously in the same test solution while rotavirus removal was tested separately. The bacteria and virus removal was tested at the start of filter operation and when permeance declined to 75, 50, and 25% of the initial value. After the first sampling point at the start of filter operation, dust was added to the test solution to accelerate clogging. The filters showed >4-log removal of rotavirus and >3-log removal of E. coli and MS-2 phage. With such rejection performance, xylem filters would fall under the comprehensive protection (high pathogen removal)’ category (★★) as per the WHO scheme for classifying water treatment technologies. 

Since the virus particles are smaller than the expected pore size of the filters (MS-2 phage and rotavirus are 2448 and 70 nm49 in diameter, respectively, while the pore size is 100–500 nm12), the results suggest that the mechanism of virus removal is likely to be adsorption-driven. Virions can adsorb on cellulose-based materials, with cellulose nitrate reported to remove virions that are much smaller than the filter pore size.We hypothesize that the relatively slow flow rate and the large thickness of xylem filters could facilitate adsorption and removal of viruses and provide ‘comprehensive protection’ against water-borne pathogens as per WHO’s performance criteria for household water treatment technologies. However, the contaminant removal ability of xylem filters could be improved further which will be the focus of our future research/testing efforts.

References:

Link to paper

Boutilier, M. S., Lee, J., Chambers, V., Venkatesh, V., & Karnik, R. (2014). Water filtration using plant xylem. PLoS One, 9(2), e89934.

I think a core method through which we aim to incorporate diversity, equity, and inclusion is by being as much as possible amidst the population that we aim to serve and incorporate their views and inputs as much as we can. People from across all spaces are welcome into our team and really the heart of what we are trying to do and address is to help people get clean water. Incorporating that lens through our own experiences and our team's experiences is a reminder also of the work that is left to be done.

Main revenue streams: For the beachhead market, DetoXyFi will be selling the individual use devices (life span of 2 weeks). As we move towards the retail market, DetoXyFi will operate using the razor blade model. Every replaceable filter (usable life of ~ 1 month) generates a 50% gross margin and grows to 65% with scale(>200k units). In addition to the the direct revenue stream, DetoXyFi is considering two secondary sources:

Once the filters have been spent/used, DetoXyFi can resell these filters back to paper/pulp manufacturers for further transformation

Given that our technology plays a key role in eliminating carbon emissions, DetoXyFi has been approached to consider selling carbon offsets in the market against heavy polluting industries

Business model innovation: Decentralized water filtration poses a huge logistical lift that is both operationally and capitally intensive. To mitigate this, DetoXyFi will work with agencies that centralize their buying of water filtration units. For instance, agencies like Samaritan’s Purse, stores in inventory 150-200k filters annually with purchasing spread out over quarters. DetoXyFi filters will be sold to a central agency that then will disburse the filters during aid relief.

Business model scalability: Because the key raw material for our filters is considered scrap, DetoXyFi as a firm enjoys very high operational leverage (high ratio of fixed to variable costs). This allows DetoXyFi to rapidly expand profit margins that are essential to sustain marketing, product development, and sales efforts for the eventual retail market. 

MARKETING PLAN 

Launching into the beachhead market and supporting disaster relief efforts will require connecting with representatives and developing sales contracts with agencies. As such, the marketing lift is low at this stage and helps DetoXyFi conserve cash. However, once DetoXyFi enters the retail market, we are confident in our ability to reach the retail customer. DetoXyFi has successfully run digital campaigns to understand demographics, geographic zones of interest, and general channels to reach customers. 

1. DetoXyFi ran a digital ad campaign on Google to promote it’s website and spent $150 and garnered 170k impressions with a click through rate of 2.4%(2x avg CTR on google) for CPM of $0.88. Once the campaign was stopped, DetoXyFi has organic CTRs of >3% without any paid campaigns.

2. In addition to paid Google Ads, DetoXyFi has conducted SEO for for its website and the trailing 90 day CTR is a whopping 31%.

3. Similar to Google Ads, DetoXyFi ran a 1-month Facebook and Instragram ad campaign and had a CTR of 5.1% with a CPM of $2.6.

4. In addition to impressions, our ad campaigns have resulted in 150 subscribers to date from 40 countries in Asia, Europe, Africa, North and South America.

Given this very limited and inexpensive marketing campaign, we are confident that there is a lot of interest around the globe for natural water filters that provide protection against disease causing agents.

For the beachhead market, DetoXyFi will be selling the individual use devices (life span of 1 week). As we move towards the retail market, DetoXyFi will operate using the razor blade model. Every replaceable filter (usable life of ~ 1 month) generates a 50% gross margin and grows to 65% with scale(>200k units). In addition to the the direct revenue stream, DetoXyFi is considering two secondary sources:

Once the filters have been spent/used, DetoXyFi can resell these filters back to paper/pulp manufacturers for further transformation. 

Given that our technology plays a key role in eliminating carbon emissions, DetoXyFi has been approached to consider selling carbon offsets in the market against heavy polluting industries. 

We have won many grants that have provided us the seed capital: 

1. Adrian Cheng Fellowship at the Center for Social Innovation and Change Initiative, Harvard Kennedy School. 

2. Harvard iLab Spark Grant (2022,2023)

3. Harvard Health Lab Startup Pitch Competition 2023

4. Harvard Undergraduate Capital Partners 

5. Jacobson Social Impact Prize 2022

6. Penn Wharton Innovation Fund 2022

7. UPenn Startup Challenge 2022

8. Weiss Fund 2022

9. MIT Water Food and Agriculture Prize 2023