Indexed by:期刊论文

Date of Publication:2009-06-01

Journal:ENVIRONMENTAL ENGINEERING SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:26

Issue:6

Page Number:1047-1053

ISSN No.:1092-8758

Key Words:denitrification; MBR; methanogenesis; nitrogen removal; recirculation ratio; UASB

Abstract:Simultaneous methanogenesis and nitrogen removal using a combined system consisting of an up-flow anaerobic sludge blanket (UASB) and aerobic membrane bioreactor (MBR) was investigated for treating synthetic municipal wastewater. A more reliable effluent quality of above 98.0% total organic carbon (TOC) and 98.0% NH(4)(+)-N removal was achieved consistently throughout the experiments. Total nitrogen (TN) removal of up to 82.8% could also be achieved when the recycling ratio was increased from 0 to 800%. Analysis of the biogas composition showed that the degradation of NO(X)(-)-N through denitrification did not have any obvious effect on the total methane production up to a recycling ratio of 400%. A higher recycling ratio of 800% resulted in an increase of CO(2) and a decrease of CH(4), due to more sludge being washed out from the UASB into the MBR and recycled back into the UASB, which resulted in a higher dissolved oxygen (DO) concentration in the UASB. Hence, an optimal recycling ratio of 400% was suggested to achieve higher carbon and nitrogen removal efficiencies with over 56.3% methane in the biogas using the new combined system.