Effectiveness of an Upflow Roughing Filter for High Turbidity Water - Tapa blanda

In Chakwal, highy turbidity rainwater runoff and streamflows are collected in Khokhar Zar Dam to be used for water supply. Slow sand filtration (SSF) is a low-cost technology for treating raw water with turbidity below 50 NTU. Objectives of the work reported here include: study of current treatment process and highlight problems related to quality management,design and construct a pilot scale upflow roughing filter plant and to determine the optimum coagulant dose for in-line roughing filtration. The pilot plant constructed could reduce raw water turbidity from 450 NTU (Avg) to 2-10 NTU making SSF a viable option. There were a number of promising outcomes: the monitoring of physical parameters (turbidity, pH and conductivity) of raw and treated water at Chakwal water treatment plant (CWTP), the performance evaluation of multistage and multilayer UFRF, 30-50 percent removal efficiency by multistage UFRF and 30 percent by multilayer UFRF, the in-line coagulation to UFRF reveals 99 percent removal efficiency at 2½ fold reduced coagulant dose (47 mg/L of alum vs 122mg/L by the facility management and 65 mg/l of Ferric Chloride against the same).

Ghalib Hasnain, MS (Env. Eng.): Stduied physics and environmental engineering. Zahiruddin Khan, PhD (env. Eng.)- Interested in water treatment and environmental management in SMEs., HoD - Environmental Engineering, IESE-SCEE-NUST