• 关键词：氢基质自养微生物  氢基质生物膜反应器  生物还原  对氯硝基苯

• 基金项目：国家自然科学基金(No.50978190);国家高技术研究发展计划(No.2009AA062902)

• 李海翔
• 1. 桂林理工大学环境科学与工程学院, 桂林 541004;
  2. 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092

• 徐晓茵
• 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092

• 梁郡
• 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092

• 夏四清
• 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092

• 摘要：将中空纤维膜微孔曝气和生物膜工艺结合设计出一种新型的水处理工艺——氢基质生物膜反应器(MBfR),其中,中空纤维膜为自养微生物的生长载体,还可作为扩散装置使氢气均匀扩散至生物膜中.同时,对氢基质自养微生物还原降解水中对氯硝基苯(p-CNB)的可行性、还原机理和去除效果进行了研究,并分析了共存的硝酸盐(NO₃^--N)和硫酸盐(SO₄^2-)对p-CNB还原产生的影响.结果表明,MBfR生物膜中氢自养微生物能有效利用氢气为电子供体生物转化p-CNB,其中,p-CNB经硝基还原生成对氯苯胺(p-CAN),p-CAN再通过还原脱氯生成低毒的终产物苯胺(AN).经过长期运行,MBfR对进水500μg·L^-1和2000μg·L^-1的p-CNB具有稳定高效的生物降解性能,p-CNB去除率和去除通量最高达到96.9%和0.056g·m^-2·d^-1.通过投加NO₃^--N和SO₄^2-发现,p-CNB还原速率随NO₃^--N和SO₄^2-浓度升高而降低,表明p-CNB还原受到NO₃^--N和SO₄^2-的抑制.NO₃^--N和SO₄^2-对p-CNB还原产生的抑制主要与对电子供体(氢气)的强烈竞争和还原产物对脱氯微生物的毒性有关.电子通量分析进一步表明,反硝化或SO₄^2-还原消耗更多的电子,当氢气利用率受限制时将对p-CNB还原产生强烈的电子供体竞争性抑制.

• Abstract：Hydrogen-based membrane biofilm reactor (MBfR) that combines hollow fiber aeration and biofilm process is a novel water treatment technology,in which the hollow fibers serves as a growth-support medium for autohydrogenotrophic microorganisms and as a diffusion unit to supply hydrogen gas to the biofilm without bubble formation.The feasibility,reduction mechanism and performance of para-chloronitrobenzene (p-CNB) degradation,and the effects of nitrate (NO₃^--N) and sulfate (SO₄^2-) on p-CNB degradation were systemically investigated.The results showed that p-CNB can be firstly reduced to para-chloraniline (p-CAN) and subsequently dechlorinated to aniline (AN) by the biofilm with hydrogen as an electron donor.The MBfR could achieve a maximum removal percentage of 96.9% and removal p-CNB flux of 0.056 g·m^-2·d^-1 when the influent p-CNB concentrations were 500 μg·L^-1 and 2000 μg·L^-1.Bioreduction of p-CNB declined with the increasing influent concentrations of nitrate and sulfate,and this indicated that p-CNB bioreduction was inhibited by denitrification and sulfate reduction.The inhibition on p-CNB caused by nitrate or sulfate was mainly attributed to the competition for hydrogen as the electron donor and the toxicity of denitrification or sulfate reduction byproducts for dechlorinating bacteria.Analysis of electron-equivalent fluxes further revealed the strong hydrogen competition inhibition on p-CNB bioreduction when the hydrogen availability was limited for denitrification or sulfate reduction consuming more electrons.

• Key words：autohydrogenotrophic microorganisms  hydrogen-based membrane biofilm reactor  bioreduction  para-chloronitrobenzene (p-CNB)

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