Flux and performance improvement in a submerged anaerobic membrane bioreactor (SAMBR) using powdered activated carbon (PAC)

A three litre submerged anaerobic membrane bioreactor (SAMBR) was used to examine the effect of powdered activated carbon (PAC) on COD removal and flux. 98% COD removal efficiency was achieved at a high loading rate (16 gCOD l −1 d −1) and a low hydraulic retention time (HRT) of 6 h in the presence of 3.4 g l −1 of PAC. PAC addition improved start-up and performance during a hydraulic shock by buffering the volatile fatty acids (VFAs), however, a large amount of biomass was important in accommodating the higher loading rate in the SAMBR. Batch assays showed that PAC addition improved methane potential both in terms of amount and inoculation time. COD retention inside the SAMBR for three experiments was proportional to the soluble microbial products (SMPs) contribution to COD, as (VFAs) passed through the membrane at high sparging rates (5 litres per minute—LPM). Size exclusion chromatography showed that the membrane acted as an ultra-filter (