Operating cost and treatment analysis of cattle slaughterhouse wastewater by coagulation-flocculation and electrooxidation processes

Abstract

Nowadays, it is common practice to treat cattle slaughterhouse wastewater (SWW) using combined approaches such as physicochemical processes. This study aimed to analyze the treatment and techno-economic analysis of electrooxidation (EO) and combined coagulation-flocculation + electrooxidation (CF + EO) processes for the removal of chemical oxygen demand (COD), biological oxygen demand (BOD), and total organic carbon (TOC) from cattle SWW. The EO process achieved a removal efficiency of 99.9% for both COD and BOD, and 98.8% for TOC when conducted under optimum conditions (t = 300 min, anode material = BDD, J = 300 A/m2, pH = 7.5, and SEc = 3 g NaCl/L). The CF + EO process yielded similar results, requiring a treatment time of only 180 min. Specific energy consumption and total operating cost for the EO and CF + EO processes under optimum conditions were calculated as 94.5 kWh/m3 (22.3 kWh/kg COD) and 3.27 $/m3 (0.27 $/kg COD) for the EO and 54.5 kWh/m3 (26.4 kWh/kg COD) and 2.53 $/m3 (0.31 $/kg COD) for the CF + EO, respectively. The results show that the combined CF + EO process is cost-efficient in eliminating organic compounds from cattle SWW than EO alone.