Experimental evaluation of intermittent aeration of a hollow fibre membrane bioreactor

摘要

Intermittent membrane aeration provides a substantially improved energy efficiency in hollownfibre-based immersed membrane bioreactors (HF iMBRs). The benefits of intermittent aerationnhave been assessed with respect to sustaining a target flux and/or limiting the fouling rate to ansustainable level based on a small plant using full-scale HF modules. Results show that for thensame specific aeration demand per unit of permeate produced (SADp), fouling rates werensignificantly lower for 10 s filtration, 30 s relaxation (‘‘10:30’’ intermittent aeration) compared ton10:10 and continuous aeration. At a net flux (Jnet) of 23.3 litres mu00022 hu00021 (LMH), a SADp of 4.6 wasnfound sufficient to sustain operation, this value being up to 75% and 50% lower compared toncontinuous and 10:10 aeration respectively. This empirical data was compared with heuristic datanfrom 5 large scale HF iMBR plants, which revealed that 10:30 aeration can sustain a relatively highnflux (up to 25.3 LMH) under dry weather conditions in warm climates, with the recorded SADpnranging from 5.3–10.9.