Pretreatment of Wastewater Using a Combined Coagulation and Fenton Oxidation Process

Abstract

The effectiveness of combined coagulation and Fenton oxidation to pharmaceutical plant wastewater was investigated under different operational conditions such as pH, dosage, coagulants and ratio of Fe2+to H2O2. Among the nonionic polyacrylamide, cationic polyacrylamide, anionic polyacrylamide, polyaluminum chloride and polymeric ferric sulfate, anionic polyacrylamide showed the best efficiency of coagulation for the pharmaceutical plant wastewater. The results also showed that after the combined coagulation and Fenton oxidation treatment, the COD and color were reduced by 69.9% and 78.9%, respectively. The BOD5/ COD ratio increased from 0.09 in initial to 0.22 after treatment. The wastewater of outlet was easier for the sequent biological process.