Removal of tetrabromobisphenol A by conventional activated sludge, submerged membrane and membrane aerated biofilm reactors

Abstract

The goal of this study was to compare removal efficiencies of tetrabromobisphenol A (TBBPA) using typical wastewater treatment technologies, and to identify the most significant mechanisms of removal. Two types of municipal wastewater reactors were studied: a full-scale conventional activated sludge (CAS) reactor with tertiary treatment; and three pilot-scale membrane bioreactors (MBRs) having different sludge retention times (SRTs). All four reactors were fed the same influent. A third reactor type, a membrane aerated biofilm reactor (MABR) was fed tap water, ammonia, and TBBPA. TBBPA in municipal influent ranged from 1 to 41ngL−1 (n=10). The CAS effluent had an average TBBPA concentration of 0.7±1.3ngL−1 (n=3). Effluent concentrations from the MBRs were an average of 6±6ngL−1 TBBPA (n=26). Significant TBBPA removal was observed in the MABR throughout the 5week of study (p⩾0.05). Removal of TBBPA from wastewater treatment was found to be due to a combination of adsorption and biological degradation. Based on experimental results, nitrification is likely a key process therein. No significant relationship between removal of TBBPA and SRT was identified (p⩾0.05).