@article {27300, title = {Impact of AnMBR operating conditions on anaerobic digestion of waste activated sludge}, journal = {Water Environment Research }, year = {2020}, abstract = {

The impact of solids retention time (SRT) and hydraulic retention time (HRT) on anaerobic digestion of thickened waste activated sludge (TWAS) in a pilot-scale anaerobic membrane bioreactor (AnMBR) was compared with that achieved in conventional anaerobic digestions (CD). The AnMBR was able to successfully digest municipal TWAS at HRTs ranging from 7 to 15\ days and SRTs ranging from 15 to 30\ days. Increasing SRT in the AnMBR resulted in a significant improvement in COD and VS removal efficiency when compared against CD operating at the same HRT. The VS and COD destructions (35\%{\textendash}50\%) observed in the AnMBR were similar to those observed in CD operating at the same SRT but longer HRTs. Operation at elevated ratios of SRT/HRT resulted in the production of a thickened biosolid (2\%{\textendash}3\% TS). Specific methane production values for AnMBR operating at HRT-SRT ratios of 15{\textendash}30, 7{\textendash}30, and 7{\textendash}15 were 0.19, 0.19, and 0.14\ m3\ CH4/kg of COD fed, respectively, showing a 25\% increase in methane production with SRT. A model based upon describing hydrolysis of biodegradable solids using first-order kinetics was able to describe VS destruction as a function of SRT.

Practitioner points

}, author = {Wayne Parker and Martha Dagnew} }