Class Projects

Class of 1980 Gift to Thayer

Arsenic Treatment Process for Water in Nepal

Thayer 2015 Image 1

Arsenic contamination in groundwater affects millions of people around the world. In Bangladesh alone, over 60 million people are exposed to contamination levels five times higher than the World Health Organization’s acceptable standard for arsenic in safe drinking water. Arsenic poisoning symptoms include abdominal pain, diarrhea, skin disease and lesions, and can result in blood diseases, gangrene, and many forms of cancer.  The students will be working on Village Tech Solution’ SafaPani, meaning “Clean Water” in Nepali, which is an inexpensive household water filtering system that cuts arsenic concentrations to around 1 ppb (part per billion), well within the WHO limit of 10ppb.

SafaPani is comprised of a 3-bucket filtration system and uses Thayer 2015 Image 2electrocoagulation process to remove arsenic from water. The first bucket contains iron electrodes, a gas dome and an indicator LED light. Raw water is poured into the first bucket, where the electrodes inject the right amount of iron into the water, to coagulate most of the arsenic, while the gas dome displaces the water to indicate the completion of the treatment.  The contents of the first bucket are then poured into a second bucket with a sand bed and a perforated bottom. The sand adsorbs the sediments, and the filtered water percolates down into the third bucket.

SafaPani has several advantages:
– Reduces arsenic levels below World Health Organization standards
– Provides a reliable indication of arsenic removal.
– 6v battery and LED enables nighttime operation.
– Uses locally available sand that is easy to reload.
– Involves minimal operating costs.
– Can be scaled for an individual household or a village.

The following links have more information about the Class of 1980 project:

Group 15 – Production Design for SafaPani – Final Design Review

Prior Class of 1980 Projects

2013: Water filtration demonstration system in Martissant Park, Port-au-Prince, Haiti

2012: Cost-effective water delivery system in Fond des Blancs, Haiti including replacing the existing system with a new efficient pump

2011: Low-cost waste management system in Haiti to integrate with a $300 house

2010: Pico Hydro facility in Rwanda


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