Performance Evaluation of Modified Rapid Gravity Filter by Using Sand and Crushed Overburnt Brick Separated by Geotextile

The effectiveness of slow sand filters in accomplishing future water demand is becoming less, along with that, improvement in filtration efficiency of rapid gravity filter is under research. This study aimed to access the effectiveness of using novel filter media composed of crushed overburnt brick and sand separated by geotextile in rapid gravity filtration. The experiment was conducted with four rapid gravity filters by maintaining the constant influent and effluent discharge of 2.5 m ³ /m ² /h. The experiment was repeated seven times with varied influent turbidites by resuming the filtration process after backwashing with the backwash velocity of 21 m ³ /m ² /h, when terminal head loss exhausted 155 cm. Turbidity removal efficiency of RGF with novel media was observed to be improved by 2.07% as compared to conventional sand filter. Further, improvement in UFRV was by 49.89%, backwash water consumption was by 58.32%, backwash time was by 3.68%. The filter run length was reached up to about 1.5 times more than that of conventional sand filter. This study suggests that, substituting sand media with innovative media, which has a filter media thickness of 75% compared to sand media, can perform effectively. Additionally, it was observed that novel media with a filter media thickness of 50% as compared to sand media can efficiently operate when influent turbidity is below 100 NTU.