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【目的】水溶性的Cr(Ⅵ)对环境及人类造成的危害是社会亟待解决的问题。Cr(Ⅵ)还原菌株的分离筛选、还原特性的分析和在微生物燃料电池中的应用为六价铬污染水体的微生物修复提供科学依据和新的方法。【方法】从黄河兰州段排污口采集样本,用平板法分离筛选获得具有Cr(Ⅵ)还原能力的菌株,并将Cr(Ⅵ)还原能力最强的LZU-26菌株应用到微生物燃料电池中,检测其产电能力和Cr(Ⅵ)还原特性。【结果】共分离得到21株具有Cr(Ⅵ)还原能力的菌株,其中LZU-26菌株Cr(Ⅵ)还原能力最强,属于Cellulosimicrobium cellilans。0.4 mmol/L初始Cr(Ⅵ)在LZU-26的作用下24 h铬还原率可达到95.89%,在48 h后达99.97%。将LZU-26运用在微生物燃料电池生物阴极,所获得的最大电压和最大功率密度分别为68 mV和6.8 W/cm~2。生物阴极Cr(Ⅵ)还原率(68.9%)也远高于化学阴极(14.7%)和对照组(2.7%)。【结论】利用Cr(Ⅵ)还原菌作为微生物燃料电池生物阴极处理含铬废水,将会是一种高效、节能和环境友好的方法。
【Objective】 The harm of water-soluble Cr (Ⅵ) to the environment and human beings is an urgent problem to be solved in society. The separation and screening of Cr (VI) -reducing strains, the analysis of their reduction characteristics and their application in microbial fuel cells provide a scientific basis and a new method for the microbial remediation of water contaminated by hexavalent chromium. 【Method】 Samples were collected from sewage outfalls of Lanzhou section of the Yellow River. Strains were isolated and screened to obtain Cr (Ⅵ) -reducing strains. The strain LZU-26 with the strongest Cr (Ⅵ) reduction ability was applied to microbial fuel cells. The production capacity and Cr (Ⅵ) reduction characteristics were examined. 【Result】 Twenty-one isolates with Cr (Ⅵ) reducing ability were isolated. Among them, LZU-26 strain had the strongest reducing ability and belonged to Cellulosimicrobium cellilans. Under the action of LZU-26, initial Cr (Ⅵ) concentration of 0.4 mmol / L reached 95.89% after 24 h and 99.97% after 48 h. Applying LZU-26 to the bio-cathode of microbial fuel cells, the maximum voltage and maximum power density obtained were 68 mV and 6.8 W / cm ~ 2, respectively. The biocathode Cr (Ⅵ) reduction rate (68.9%) is also much higher than the chemical cathode (14.7%) and the control group (2.7%). 【Conclusion】 It is an efficient, energy-saving and environment-friendly method to treat chromium-containing wastewater by using Cr (Ⅵ) reducing bacteria as biocathode for microbial fuel cell.