Here’s how CEE senior Jessica Huang explains it:

In the 1980s and 90s, the Cambodian government and other organizations launched well-meaning campaigns to install wells in rural villages, sometimes one well for every two homes. Clean water became plentiful and convenient, and the wells turned into prized community possessions.

But, in an unfortunate accident of geography, some sources of Cambodia’s groundwater contain dangerous levels of naturally occurring arsenic, a fact not discovered until later. A tasteless, colorless, odorless chemical, arsenic remains in the body once ingested and slowly poisons it, causing disfiguring lesions, cancers and, in some cases, death. Two million Cambodians are at risk.

Now there’s an effort to right the wrong without destroying a useful infrastructure. Enter Huang. She’s part of a Berkeley student team guided by Energy and Resources Group adjunct professor Ashok Gadgil. Their answer may be “sushi.”

Sushi 4.0—as the team calls its prototype built from layers of rolled iron sheets—removes arsenic from water in a low-cost process called electrochemical arsenic remediation. Small amounts of electricity continuously dissolve the sheets of iron, forming rust. Rust absorbs the arsenic. The device, in its final form, will filter out the arsenic-laden rust or facilitate its settling.

Huang spent a month in Cambodia this summer helping her team test the prototype and study its implementation in partnership with local contacts.
“What do you tell people [who have arsenic in their water supply] when they have no alternative? Don’t use the water? That’s why we want to get something out there to them,” she says.

Her involvement began in ER 291, Design for Sustainable Communities, a class she took from Gadgil last spring. His assignment: build a working prototype based on groundbreaking technology that had already been developed at the Lawrence Berkeley National Laboratory. To meet design goals, the device had to produce less than 120 milligrams of waste per person per day.

While advanced technologies exist for eliminating arsenic from water, rural Cambodia presents several design challenges. The solution must be durable (can it survive a mountain trek and river crossing?), cost pennies per person per day, and require little maintenance. It must be designed so that users can maintain it and become vested owners.

Long story short: After hours and hours in the lab, after several prototype ideas and iterations, the team flew Sushi 4.0 to Cambodia, and the device yielded encouraging results. Huang’s group is now developing a licensing strategy so their solution can be scaled up for manufacturing. (Huang also majors in business administration.)

For her part in the team project, Huang was awarded a J.W. Saxe Prize for Public Service this spring and pooled the $2,000 award that came with it back into the research. She will graduate in December after passing the team’s knowledge on to new student researchers (Interested? E-mail jesshuang@berkeley.edu.) but is taking with her a new appreciation for water.