Evaluation of Pre-ozonation Coagulation and Flocculation Process with Poly Aluminium Chloride Coagulant Material and Cationic Polyelectrolyte Coagulant Aid in Treatment of Hospital Wastewater

Hospital wastewater consists of different compositions, including medicines, disinfectants and pathogens that are excreted mainly in the absorbing wells or enter into the municipal wastewater network that leads to a contamination of water resource crisis. The purpose of this study is to evaluate pre-ozonation coagulation and flocculation process with Poly Aluminium Chloride coagulant material and cationic polyelectrolyte coagulant aid in the reduction of hospital wastewater pollution load. In this study, the laboratory system including ozone generator with a capacity of 19.8 go3/h, ozonation reactor with the volume of one liter, air diffuser and Jar-test instrument using Poly Aluminium Chloride coagulant and cationic poly electrolyte were used, and parameters of BOD5, COD, and TSS in accordance with standard methods for testing water and wastewater were investigated. Based on the results of this study, Poly Aluminium Chloride a dose of 200 mg/L with cationic poly electrolyte with a dose of 1 mg/L caused a removal efficiency of 50.0%, 81.0%, and 84.0% for COD, BOD5, and TSS respectively. Pre-ozonation with the optimal dose of 19.8 go3/h for 15 minutes increased the removal efficiency of COD, BOD5, andTSS in the process of coagulation and flocculation to 54.0%, 87.0%, and 89.0% respectively. The preozonation slightly increased the efficiency of the coagulation and flocculation process with Poly Aluminium Chloride coagulant material and cationic Poly electrolyte coagulant aid in removing the studied parameters and also ozonation reduced the amount of Poly Aluminium Chloride coagulants used.