Removals of endocrine disrupting compounds during landfill leachate treatment in two-stage aerobic sequential batch reactor: Effect of Alcaligenes faecalis no.4 bio-augmentation

Abstract

The effect of Alcaligenes faecalis no.4 (A. faecalis no.4) in two-stage sequencing batch reactor (SBR) treatment of endocrine disrupting compounds (EDCs), i.e., bisphenol A (BPA), di-n-butyl phthalate (DBP) and bis-2-ethyl hexyl phthalate (DEHP) containing in landfill leachate was investigated. Two aerobic SBRs were operated without (C-SBR) and with A. faecalis no.4 bio-augmentation (B-SBR) at a hydraulic retention time (HRT) and solid retention time (SRT) of 3 and 30 days over 280 days. The removals of BPA, DBP, and DEHP were significantly improved to 91.1%, 84.5%, and 80.9% from their average influent concentrations of 185, 244, and 532 μg/l under the presence of A. faecalis no.4 through their enhanced biodegradation. The A. faecalis no.4 bio-augmentation helped promote a strong consortium of bacterial genera reported as BPA, DBP, and DEHP degraders in microbial sludge. This study demonstrated the technical feasibility of applying SBR with A. faecalis no.4 in landfill leachate treatment with effective EDC removals.