DEVELOPMENT OF A SLOW SAND WATER FILTER WITH ACTIVATED CARBON USING LOCALLY SOURCED MATERIALS

Abstract

Water treatment plays a greater role in the water supply chain. It helps in the sustainable management of vital water resources alongside water conservation and efficiency. Sand has been used to purify water for over a thousand years and it still remains the dependable methods of making water fit for drinking. A biological sand filter (BSF) was developed using locally sourced
materials. The filter media comprising of gravel, fine cloth, sand and layer of activated carbon. The activated carbon layer was activated with a 25% CaCl m/m solution. This design was chosen over others for its low cost and simplicity. Parameters monitored included absorbance, COD, total coliforms, turbidity, conductivity, temperature, pH, total solids, and flow rate. The performance of
the filter was evaluated by analyzing both the raw and treated water samples in the laboratory. The flow rate was also determined by allowing a known volume of untreated water to run while monitoring the time. The water quality analysis showed an appreciable reduction in calcium, magnesium, potassium, sodium and iron in untreated water to 14.62, 17.46, 1.43, 2.39, and 0.1 in
treated water respectively. The pH and E.coli was 6.2 and 10 respectively. Taste, colour and turbidity were also tested for and the result shows an appreciable reduction. The flow rate was evaluated to be 0.01692m3 /hr (i.e. 16.92L/hr). The filter is cost effective and easy to construct, operate and maintain.