Water treatment for rural areas by slow sand filtration

This paper deals with slow sand filtration as a water treatment technology to solve the needs of water for human consumption in rural areas. The study was conducted in a lake located in the southern island of Santa Catarina, Brazil. The filter was operated with a filtration rate of 4 m3/m2d to produce approximately 2500 liters per day. The filter was cleaned when the loss of load in the filter reaches 0.80 m indicating the end of the filtration run. The sand bed depth was 400 mm, with a uniformity coefficient <1.4 and 0.55 mm effective size. The filters were operated for 6 filtration runs lasting an average of 16 days each during the first half of 2009. We monitored the water quality parameters by measuring color and turbidity. Removal efficiency of color and turbidity was observed to be approximately 78 % and 81 % respectively. The results obtained indicate that the slow filters have a great potential application for rural families to meet their water needs by treating the water themselves.