Novel Mass Bio System (MBS) and its potential application in advanced treatment of coal gasification wastewater

Abstract

In this study, a Novel Mass Bio System (MBS), a suspended biologically activated carbon granular carrier cubic particle with 2–5mm side length and 1.02–1.08 specific gravity was developed for advanced treatment of coal gasification wastewater. A laboratory scale anaerobic AnaEG (advanced anaerobic expanded granular sludge bed)–primary aerobic BioAX (a novel environmental biotechnological aerobic process with internal circulation)–MBS aerobic fluidized bed nitrification bioreactor–MBS expended bed denitrification bioreactor–secondary aerobic BioAX reactor system was operated over a period of 260 days. With an influent concentration of chemical oxygen demand (COD) 3000 mg L⁻¹, total phenol (TP) 300 mg L⁻¹, and ammonium nitrogen (NH₄⁺-N) 149 mg L⁻¹, the effluent COD, TP, NH₄⁺-N, could be decreased to 159 mg L⁻¹, 6 mg L⁻¹ and 0.12 mg L⁻¹, respectively. The maximum removal efficiencies of COD, TP, and NH4⁺-N were respectively 94.7%, 98%, and 99.9%. With hydraulic retention time (HRT) of 36 h, methane content was 60% and methane productivity was 0.11 L CH₄/g COD. Pyrosequencing analysis showed the enrichment of ‘rare microbes’. Contrary to expectation, nitrifying bacteria, Ohtaekwangia (Bacteroidetes) was the most abundant rare bacteria with 37.1% of the microbial community entrapped in MBS.