Effects of Sand Preparation Techniques on the Performance of Bio-Sand Filter

The study sought to evaluate the effects of sand preparation techniques on the performance of bio-sand filter. Four bio-sand filter prototypes were constructed and filled with sand prepared through various techniques. The preparation techniques of the sand were (a) washing with treated water, (b) drying in the sun for a day, (c) drying in oven at 105oC and (d) soaking in chlorine. River water was applied in this study. Turbidity, Total Suspended Solid (TSS) and the Coliform tests were performed on the river water before and after passing through the bio-sand filter prototypes. The tests were done to evaluate the impact of sand preparation techniques on the efficiency of bio-sand filter in reducing turbidity, total suspended solids and Coliforms content. The results showed that all the sand preparation techniques generally reduce turbidity, total suspended solids and Coliforms content appreciably. However the soaked with chlorine prototype was the most efficient, with the removal efficiencies of 97.97 % for Coliforms, 92.86 % for TSS and 89.17 % for Turbidity. Next was the sand washed with treated water prototype achieving removal efficiencies of 96.99 % for Coliforms, 96.43 % for TSS and 80.81 % for Turbidity. The study showed that the bio-filter sand prepared by soaking in chlorine achieved the highest removal efficiency.