Hydrolysis of polyaluminum chloride prior to coagulation: Effects on coagulation behavior and implications for improving coagulation performance

Comparison between conventional and reverse coagulation tests. Initial kaolin concentration 100 mg/L; final pH 8.0; 21 ± 1°C; premixing of PACl solution: G = 245 s− 1, 3 min; rapid mixing: G = 245 s− 1, 3 min; slow mixing: G = 15 s− 1, 10 min; settling: 10 min.223