Appropriate technology water treatment processes for MaeLa Temporary Shelter, Thailand

Abstract

This thesis recommends the use of horizontal-flow roughing filters to treat spring water of variable annual quality in MaeLa Temporary Shelter, Thailand. The public drinking water system for 45,000 refugees is overseen by Aide Medicale Intemacionale, with which this project was conducted. Half the drinking water for the camp is provided by thirteen springs. The volume and turbidity of these springs varies annually, correlating with the rainy and dry seasons. Treating the varying turbidity and volume at these sources so that the water can be effectively disinfected is the treatment goal. Available materials and operation and maintenance capabilities are also design parameters. Horizontal-flow roughing filtration was determined to fit these parameters and a design with two equivalent filters operating in parallel is recommended. One important feature of the filters is baffles that dictate the flow path of water through the filter. A second feature is an outflow at the top of the filter that will maintain a constant water volume in the filter. The feasibility of the design is based on flow tests and turbidity measurements taken on site as well as weekly flow rates and turbidities for 2007 provided by AMI. The requirements for mechanical regeneration of the filter are also determined.