Slaughterhouse Wastewater Treatment by Integrated Chemical Coagulation and Electro-Fenton Processes
Edris Bazrafshan, Hamid Reza Zakeri, Melissa Gurgel Adeodato Vieira, Zahra Derakhshan, Leili Mohammadi, Amin Mohammadpour, Amin Mousavi Khaneghah
Abstract
The slaughterhouse industry produces large amounts of highly polluted wastewater which needs to be treated before being discharged water. Thus, this work was conducted to investigate the feasibility of treating slaughterhouse wastewater using combined chemical coagulation and electro-Fenton methods. We studied the effect of process parameters such as polyaluminum chloride (PAC) concentration (25, 50, 75, 100 mg/L) for chemical coagulation and hydrogen peroxide concentration (500, 1000, 1500, 2000, 2500, 3000, 4000 mg/L), the pH of the solution (3, 5, 7, 10), and the reaction time (5, 10, 15, 30, 45, 75, 120 min) and the voltage (10, 20, 30, 40 V) on the removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), total Kjeldahl nitrogen (TKN), and fecal coliforms (FC). The optimum removal efficiency for the electro-Fenton process was obtained at PAC = 75 mg/L, reaction time = 75 min, pH = 3, H2O2 = 2500 mg/L, and V = 20 V, which resulted in the removal efficiency of 89.55% for COD, 88.88% for BOD, 91.27% for TSS, 69.23% for TKN, and 100% for FC. The findings demonstrated that combined chemical coagulation and electro-Fenton processes effectively and efficiently treat slaughterhouse wastewater. The results of this research can be used by competent authorities to increase the efficiency of slaughterhouse wastewater treatment and to protect the environment.