Performance of simultaneous organic and nutrient removal in a pilot scale anaerobic–anoxic–oxic membrane bioreactor system treating municipal wastewater with a high nutrient mass ratio

Submerged membrane bioreactors (MBRs) have been gaining in popularity in various types of wastewater treatment. One drawback of submerged MBRs is difficulty in removing nitrogen as they are accompanied with intensive aeration inside the reactor and therefore principally operated under aerobic conditions. In order to address this problem, a simple modification for submerged MBRs, insertion of baffles to create alternative aerobic/anoxic conditions, was proposed. In this study, the performance of the proposed baffled membrane bioreactor (BMBR) was investigated based on a pilot-scale experiment using a real municipal wastewater. With appropriate operating conditions, the BMBR could remove more than 70% of total nitrogen contained in the feed water without any external carbon source. The BMBR demonstrated a good treatment performance in terms of TOC and phosphorus removal as well. Increase of trans-membrane pressure difference was subtle, which might be attributed to the alternative creation of aerobic/anoxic conditions.

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Efficient Biological Nutrient Removal in a Membrane Bioreactor Using Denitrifying Phosphorus Removal and Simultaneous Nitrification and Denitrification

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.507.693 ◽

2014 ◽

Vol 507 ◽

pp. 693-701

Author(s):

Jiu Yi Li ◽

Nian Peng Wu ◽

Jin Li ◽

Ai Min Wang ◽

Yong Chen ◽

...

Keyword(s):

Nutrient Removal ◽

Phosphorus Removal ◽

Membrane Bioreactor ◽

Phosphorus Release ◽

Biological Nutrient Removal ◽

Return Flow ◽

Denitrifying Phosphorus Removal ◽

Bioreactor System ◽

Removal Processes ◽

The Impact

Biological nutrient removal (BNR) is generally integrated in municipal wastewater treatment plants to alleviate the impact of treated effluent on receiving watersheds. This paper studies the performance of BNR in a membrane bioreactor system consisting of anaerobic, anoxic, micro-aerobic and aerobic compartments treating a synthetic wastewater containing low organic matters. The membrane bioreactor system designed an anti-stream, stepwise return flow scheme to produce ideal conditions for the occurrence of simultaneous nitrification and denitification and denitrifying phosphorus removal processes. The proposed membrane reactor system has established higher biomass concentrations and ideal environments for biological nutrient removal processes, which results in high nutrient removal efficiencies treating low organic wastewaters. Four compartment configurations in the reactor system minimized the impact of oxidized nitrogen species in return flow on phosphorus release in the anaerobic tank and the anti-stream, stepwise return flow scheme encouraged the utilization of nitrate as the electronic acceptor in phosphorus uptake in the micro-aerobic tank. Denitrifying phosphorus removal and simultaneous nitrification and denitrification processes are the main mechanisms responsible for efficient nutrient removal. High phosphorus release activities and high phosphate concentration in the anaerobic tank make it is potentially feasible to recover phosphorus resource from wastewater.

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