Construction and testing of a drinking water disinfection and filtration system for developing nations

Point of Use (POU) drinking water treatment shows potential to save the lives of thousands who die every day from preventable waterborne illnesses. Most POU treatment focuses on either household scale filtration or community-level disinfection, but there remains a need for a low-cost batch treatment system incorporating both filtration and disinfection. Consequently, a drinking water treatment system including sand filtration and locally-generated chemical disinfection was constructed from inexpensive and accessible materials. The prototype consisted of two barrels and a circulation pump, with water cycling through a gravity sand filter before being injected with chlorine produced through saline electrolysis. The treatment efficacy of the prototype was determined by turbidity reduction and disinfection effectiveness. Ninety gallons of surface water displayed a 70% reduction in turbidity after ninety minutes of operation, and no coliform bacteria were detected in the system upon completion of treatment. The purchase cost of the system components was less than $900 (2017) and the total project displays an estimated net present value of ($4,100) over 10 years. The system is safe, simple, and reliable, and could be foundational to the development and implementation of chemical disinfection in batch filtration processes for POU water treatment. .