The performance and membrane fouling rate of a pilot-scale anaerobic membrane bioreactor for treating antibiotic solvent wastewater under different cross flow velocity

Abstract

The performance of a pilot-scale anaerobic membrane bioreactor (AnMBR) for treating antibiotic solvent wastewater under different cross flow velocities (CFV) was investigated. Effects of mixed liquid suspended solids (MLSS), colloid total organic carbon (TOC) and CFV on membrane fouling rate (RMF) were also explored in this paper. Throughout 341 days of experiment, the average total removal rate of N, N-Dimethylformamide (DMF) was 98.5% which hardly affected by the variation of CFV, and the compliance rate of DMF was 92% according to the Chinese standard (<25 mg/L). However, the relevant high total removal rate of M-cresol (MC) was achieved as 97.5%, the content of effluent failed to meet the national level emission standard (<0.1 mg/L). The biogas yield and the methane content of the biogas increased gradually with the increase of CFV, and the average methane content were over 70%. There were four kinds of methanogens in AnMBR, Methanosaeta spp was the largest methanogenic community, with an area of 45–70% of the archae. There was a linear relationship between colloid TOC and RMF at different MLSS concentrations. Then a universal mathematical model for the changes of RMF with influence factors was established. The result showed that model well fitted the laboratory data. It is suggested that the model proposed could reflect and manage the membrane fouling of AnMBR treating antibiotic solvent wastewater.