Abstract:
This research investigated the performance of fl oating media fi lter in removing particles and dissolved organic matter from surface water. Pilot-scale study consists of fl oating plastic media pre-fi lter connected with either granular activated carbon (GAC) or sponge biological fi lter (BF) bed. In the fl oating plastic media fi lter, coagulation and fl occulation processes using poly-aluminum chloride (PACl) as coagulant at an optimum dose of 8 mg/L helped removing particles from raw water. The fl oating media fi lter was operated a fi ltration rate of 11 m3/m2.h whereas those in GAC and BF units were maintained at 2 m3/m2.h. Continuous operation for over 120 days gave 98% and 99% average removal effi ciencies of turbidity and UV254 in fl oating media fi lter in combination with GAC unit whereas and 78% and 52% removal effi ciencies of turbidity and UV254 removal were obtained in fl oating media fi lter in combination with BF. The removal of dissolved organic carbon in GAC and BF units reduced chlorine demand for disinfection by 29% and 14%. It could also reduce the sum of trihalomethane (THMs) ratio from 1.1 to 0.1 and 0.5 respectively.
