New urban wastewater treatment with autotrophic membrane bioreactor at low chemical oxygen demand/N substrate ratio

作者：Yang Y; Lesage G; Barret M; Bernet N; Grasmick A; Hamelin J; Heran M^*

来源：Water Science and Technology, 2014, 69(5): 960-965.

DOI：10.2166/wst.2013.814

• activated sludge population dynamics
• autotrophic membrane bioreactor
• COD/N ratio
• energy demand
• nitrogen removal

The potential for total nitrogen removal from municipal wastewater has been evaluated in an autotrophic membrane bioreactor running with a low chemical oxygen demand (COD)/N ratio to simulate its combination with an upstream physicochemical process that retains a large proportion of organic matter. The tests were conducted in a laboratory scale submerged membrane bioreactor loaded with a synthetic influent. Nitrogen loading rate was 0.16 kg(N-NH4+).m(-3).d(-1) and sodium acetate was added as a carbon source. Results have shown that nitrogen elimination can reach 85% for a COD/N ratio of 5, with COD removal exceeding 97%. However, a COD/N ratio of 3.5 was found to be the limiting factor for successfully reaching the overall target value of 10 mgN.L-1 in the effluent. Nevertheless, low COD/N ratios make it possible to work with low total suspended solid concentrations in the bioreactor, which greatly facilitates membrane fouling control by a simple aeration and backwashing strategy.

• 出版日期2014