Li Tinggang, Liu Junxin, Bai Renbi, Wong F S
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China.
Environ Sci Technol. 2008 Mar 15;42(6):2099-104. doi: 10.1021/es702150f.
A membrane-aerated biofilm reactor (MABR) was studied for the treatment of wastewater containing acetonitrile, a typical organonitrile compound. The MABR used hydrophobic hollow fiber membranes as the diffusers for bubbleless aeration as well as the carriers for biofilm growth. The objectives were to prevent the stripping-loss of acetonitrile during aeration and to achieve acetonitrile biodegradation plus nitrogen removal simultaneously in a single biolfilm on the membranes. In the MABR, oxygen and substrates were supplied to the biofilm from opposite sides, in contrast to those from the same side in conventional biofilm bioreactors. Operational factors, including surface loading rate and upflow fluid velocity in the bioreactor, on the effect of acetonitrile biodegradation performance were examined. The profiles of dissolved oxygen concentration and microbial activities and populations in the biofilm were investigated. Experimental results showed that, with the adapted microorganisms, removal of acetonitrile at approximately 98.6 and 83.3%, in terms of total organic carbon and total nitrogen, were achieved at a surface loading rate (in terms of membrane surface) of up to 11.29 g acetonitrile/ m2 x d with an upflow fluid velocity of 12 cm/s and a hydraulic retention time of 30 h. The biofilm on the membranes developed an average thickness of about 1.6 mm in the steady state and consisted of oxic/anoxic/anaerobic zones that provided different functions for acetonitrile degradation, nitrification, and denitrification. The acetonitrile-degrading bacteria in the MABR appeared to secrete more extracellular polymeric substances that enhanced the attachment and development of the biofilm on the membranes. The study demonstrated the potential of using the MABR for the treatment of organonitrile wastewater.
研究了一种膜曝气生物膜反应器（MABR）用于处理含乙腈的废水，乙腈是一种典型的有机腈化合物。该MABR使用疏水性中空纤维膜作为无泡曝气的扩散器以及生物膜生长的载体。目标是防止曝气过程中乙腈的吹脱损失，并在膜上的单一生物膜中同时实现乙腈生物降解和脱氮。在MABR中，氧气和底物从相反的两侧供应到生物膜，这与传统生物膜生物反应器中从同一侧供应不同。研究了包括生物反应器中的表面负荷率和上流流体速度等操作因素对乙腈生物降解性能的影响。研究了生物膜中溶解氧浓度、微生物活性和种群的分布情况。实验结果表明，对于经过驯化的微生物，在表面负荷率（基于膜表面）高达11.29 g乙腈/m²·d、上流流体速度为12 cm/s和水力停留时间为30 h的条件下，以总有机碳和总氮计，乙腈的去除率分别约为98.6%和83.3%。膜上的生物膜在稳态下平均厚度约为1.6 mm，由好氧/缺氧/厌氧区组成，这些区域为乙腈降解、硝化和反硝化提供了不同的功能。MABR中降解乙腈的细菌似乎分泌了更多的胞外聚合物，增强了生物膜在膜上的附着和生长。该研究证明了使用MABR处理有机腈废水的潜力。
