عنوان مقاله [English]
The importance of filters in drinking water systems is increasing because it can remove considerable percentage of bacteria and diseases-causing microorganisms with minimal cost. In this context, the use of sand filters to removes water turbidity is common. The backwashing of sand filters remove deposits which are formed on the sand bed. Optimization of the backwash operation has a particular importance due to the volume of water used for backwashing sand filters (about 2-3% of the volume of filtered water). The measurement of wastewater turbidity in the operations can be an appropriate criterion for evaluating the effectiveness of Backwash operations. In this study, the Backwash operation of three sand filters are optimized by examination of the plots of turbidity versus time during the backwash of filter. In this study, backwash operation of three sand filter beds made of quartz sand particles has been studied. The results show that the optimized pattern of backwashing operation can be proposed by changing the air blowing time of backwash operation.