Can PAC and PAM be directly added into domestic sewage to reduce COD? That is, only coagulation and sedimentation are used to treat sewage. If it can be handled, how much COD can it handle?
Yes, PAC broke the charge balance of the system. After flocculation and precipitation with PAM, the charged colloid in the original system was flocculated and the organic matter content was reduced, so the cod would be reduced, but not much. If the COD is high, it must be combined with biochemical treatment, and simple physicochemical treatment may not solve the problem.