Food waste treatment in an anaerobic dynamic membrane bioreactor (AnDMBR): Performance monitoring and microbial community analysis

Abstract

The applicability of a dynamic membrane (DM) was examined in the anaerobic treatment of high-strength food waste. A DM was established on woven polyester with a pore size of 50 µm, which achieved a solids retention time to hydraulic retention time ratio of 2.1:12.1. The highest average rate of methane production (1.1 L CH4/L/d) was achieved with an organic loading rate (OLR) of 5.0 g chemical oxygen demand (COD)/L/d. Propionate was the most abundant volatile fatty acid (VFA) for OLRs above 3.1 g/L/d, but concentrations were maintained below 0.9 g/L. Up to 82% of the VFAs in the mixed liquor was reduced in the effluent, implying high methanogenic activity of the DM. Microbial assays confirmed a higher archaeal and bacterial content in the DM than in the mixed liquor at shear velocities above 1.0 cm/s. Methanolinea tarda, which is known to be propionate tolerant, was the predominant archaea in the DM.