Post-treatment of anaerobic reactor effluent for reuse using a triple filtration system

Abstract

This study evaluated the triple filtration technology efficiency as a post-treatment of anaerobic reactor effluent. This study was carried out employing different concentrations of ferric chloride as coagulant and peracetic acid or calcium hypochlorite as oxidant. The filtration rates used were 150 m³/m² d and 120 m³/m² d. The efficiency of the system was evaluated through physicochemical and microbiological parameters. The best conditions found were those using 20 mg/L ferric chloride, 120 m³/m² d filtration rate and 0.8 and 1.6 mg/L free chlorine. These conditions resulted in turbidity <1.0 NTU, Total Organic Carbon <1.5 mg/L, Chemical Oxygen Demand <1.0 mg/L, Biochemical Oxygen Demand <1.0 mg/L, in addition 100% removal of Total Phosphorus and Linear Alkylate Sulfonate. The post-oxidation process promoted inactivation of 100% Total Coliforms and E. coli. The post-treatment was able to produce effluent with characteristics that enable its urban, damming, creation and maintenance of wetlands, industrial and agricultural reuse proposed by USEPA.

Keywords: Coagulation; Oxidation; Post-treatment; Reuse; Triple filtration.