Effect of Coagulants on Operation of Activated Carbon Adsorption Tank

The surface water treatment process in Third Waterworks of Beijing Waterworks Group adopted FeCl3as coagulant. There were two problems in the operation: one was the black backwash water in activated carbon adsorption tank; the other was the high outflow turbidity of V-filter and activated carbon adsorption tank. To this end,a lot of adjustments to the process parameters were carried out,but these problems were not completely solved. The coagulants were compared by coagulating mixing examination and filtering performance examination. FeCl3was replaced by PAC based on the analysis of experimental data. After 6 months of operation,the problems were solved.