Engineering Clean Water for Communities
Jonathan Bessette, a graduate research assistant in engineering at MIT and MIT Morningside Academy for Design Fellow, prototyped a deployable water desalination system powered by solar energy. His design offers a solution for use in humanitarian emergencies, providing drinkable water to underserved, remote communities.
By Adelaide Zollinger
Mar 21, 2023
Jonathan Bessette, a PhD candidate working with Associate Professor Amos Winter in the MIT GEAR Lab (Global Engineering and Research Lab), is a 2022 MIT Morningside Academy for Design Fellow. Focusing on machine design and mechanical engineering, Jonathan has been designing a deployable desalination system for use in humanitarian emergencies, and more broadly, in rural areas with high resource constraints. His vision is a pallet-sized system that can easily be transported on an aircraft. “I wanted it to be solar powered, requiring minimal maintenance, and providing good water to communities,” he says.
Jonathan retraces the initial inspiration for the project to a student field trip around central and southern India. Exploring local traditional architecture, he recounts being struck by ancient water collection and extraction methods—some practiced by communities for generations. To name only one, stepwells (known as “vav,” or “bawdi”) collect rainwater during the monsoon, and offer a series of steps leading down to the water level.
Turning non-potable water drinkable usually involves two main steps: filtering physical particles, and killing germs or biological contaminants, often by chlorination. In the context of emergency scenarios, these steps often take place in isolated or off-grid areas offering limited resources. Removing chemicals such as heavy metals, or salt in water is not often feasible in such regions.
Jonathan’s design approach finds its roots in deterministic design, often described as “creativity based on facts,” through a process of risk assessment and the systematic collection, creation and analysis of design information. In the first years of his PhD, he spent a lot of time studying the barriers to desalination and water treatment in the context of humanitarian crises—talking to community members and practitioners such as NGOs working in the field to assess which tools were used, and their common problems. “The complexity and high cost of standard desalination systems and chemical treatments, which require a lot of maintenance, mean they usually can’t be used in emergencies. So my main question was ‘How can we do better, what can we leverage here at MIT?’”
One of Jonathan’s main challenges has been addressing the battery. Large-size battery banks cannot be shipped on aircraft, are very costly, and add operational complexity. They are also difficult to maintain. Which is why, in terms of design, Jonathan tried to eliminate any element that might lead the system to fail. Shifting to renewable energy using solar panels minimizes the amount of failure points on his prototype, allowing for an independent and robust system with excellent longevity—it should be able to work for several years after being deployed (up to 20 years), which is ideal for capacity building after emergencies.
Jonathan’s prototype, which can filter water to cover consumption for up to 3,000 people per day, offers an off-grid system that has comparable costs to on-grid ones, making it highly suitable for use in remote areas or emergencies. In February 2022, it was deployed in New Mexico at the Brackish Groundwater National Desalination Research Facility, near the White Sands National Park. It’s an area offering a consistent source of brackish water, i.e., groundwater with dissolved solids content which must be desalinated in order to be drinkable. “When people hear desalination, they often think of ocean water. But presently, our main focus is actually salty groundwater. Because of climate change, increased sea level rise and aquifer intrusion, groundwater is becoming more and more unusable for people. Unfortunately, in many scenarios, it’s their main resource. This isn’t only the case in the US, but also in places like Kenya, India, Jordan, and Bangladesh, to name a few.” This phenomenon, known as “salinity intrusion,” causes significant economic and social disruption, including population displacement, highlighting the importance of deployable and affordable water treatment solutions.
At the heart of Jonathan’s course of action, balancing research and practical objectives to develop the project in the field, and see it really benefit people, has been a crucial motivation. “It’s very fulfilling work. Being able to connect with stakeholders and users keeps my passion going,” he shares. Beyond general oversight of the project, Jonathan worked on the design for control, electronics, hydraulics and piping. He describes receiving a lot of support on the pilot system from staff members, students, and UROPs. “In the broader desalination team, we all work towards similar goals. We each pitch in and help out on other projects when there are little bits to be done. Getting the prototype across the country from Boston to New Mexico, driving and trailing, was really quite a task!”
For next steps, Jonathan has identified a few possible paths. “I’m looking at either simplifying the system’s architecture even further and building redundancies for reliability. Now that we’ve removed the batteries, I would like to reduce the amount of piping and valves to minimize possible points of failure. I also want to look at the chlorination, and simplify filtration,” he adds.
Most systems use cartridge filters to remove physical particles in the beginning of the process. These are typically commercial commodities which are purchased and thrown out over and over again. Jonathan is therefore looking at filter alternatives such as sand, disc, and hydrocyclone filters that don’t have to be constantly shipped and replaced.
Chlorination is a traditional step in practice, but shipping chlorine in disaster scenarios often implies complex logistics because of the lack of infrastructure, incurring long lead time and increased costs. Jonathan is looking into enriching his system with electrochlorination (by which electrolysis of saltwater produces a chlorinated solution). “It’s basically using a little bit of the bad stuff you took out of the water to do disinfection on site instead of having to ship chemicals like chlorine,” he explains. In the long term, he believes this work will be carried forward into practice via a company co-founded with fellow staff members. Jonathan concludes:
Jonathan gives special thanks for their support to Staff Engineer Shane Pratt, other staff members from his lab such as Jeffrey Costello, Elizabeth Brownell, and Ben Judge, students such as Jacob Easley, Jimmy Tran, and Melissa Brei, and UROPs, such as Muriel McWhinnie.