A Comprehensive Evaluation of Parameters Affecting Treating High-Strength Compost Leachate in Anaerobic Baffled Reactor Followed by Electrocoagulation-Flotation Process

In this study, high-load compost leachate was successfully treated in a hybrid anaerobic baffled reactor (ABR)/electrocoagulation-flotation (ECF) system. The interaction effects of operational factors in ABR, i.e., influent chemical oxygen demand (COD), hydraulic retention time (HRT), and COD/nitrogen (N) ratio on the efficiency of COD removal and biogas production rate (BPR) were analyzed and correlated by response surface methodology (RSM). The optimum conditions of ABR were found at COD = 8250 mg/L, HRT = 46 h, COD/N ratio = 70, where COD removal and BPR reached 84 % and 76 mL/mg h, respectively. COD/N ratio and HRT were found to be the most effective parameters, respectively, on COD removal and BPR. The organic loading rate (OLR) values varied from 0.45 to 5.66 kg/m3 day. The data presented indicate that the ECF reactor successfully satisfies the discharge criteria for most of the experimental domain. The outcomes have exposed that sequential ABR/ECF reactors are a competent system in treating low- and high-strength compost leachate.