碳源对生物阴极降解对硝基苯酚效能及生物阴极群落结构分析

Effect of carbon source on PNP degradation and biocathode community structure in bioelectrochemical system

研究不同碳源类型对双室生物电化学反应器(biocathode bioelectrochemical system,BES)生物阴极(biocathode)降解对硝基苯酚(p⁃nitrophenol,PNP)效能的影响.以碳酸氢钠和葡萄糖作为碳源,研究不同碳源类型下BES反应器效能和生物阴极的微生物群落结构.BES反应器效能和PNP去除率受到碳源类型的影响,以葡萄糖作为碳源时PNP去除率比碳酸氢钠为碳源的去除率在12 h和24 h分别提高了约3倍和1倍.RNaHCO3和RGlucose的PNP去除速率常数随碳源转换分别从(0.022±0.002)h^-1和(0.059±0.009)h^-1减小到(0.018±0.001)h^-1和(0.042±0.002)h^-1,PNP去除率分别下降了36%和6.9%.RNaHCO3和RGlucose的PNP降解速率常数在外加电压由0.5 V转换为0 V时分别下降到(0.004±0.00061)h^-1和(0.007±0.0006)h^-1,再次转换为0.5 V时PNP降解速率常数升高到(0.022±0.002)h^-1和(0.062±0.004)h^-1.454⁃焦磷酸测序结果表明碳源类型导致阴极微生物群落结构的显著差异.以碳酸氢钠为碳源的生物阴极富集Proteobacteria,而以葡萄糖为碳源的生物阴极Firmicutes和Bacteroidetes成为优势菌门.

In order to determine the effect of carbon source on the PNP degradation efficiency and microbial community structure of biocathode,the sodium bicarbonate and glucose were used as carbon source in the double chamber bioelectrochemical system(BES).The results showed that the carbon source altered the performance of reactors and PNP degradation.The PNP degradation efficiency used glucose were 3 times and 1 times higher than used sodium bicarbonate at 12 h and 24 h,respectively.The PNP removal rate constant of RNaHCO3和RGlucose reduced from(0.022±0.002)h^-1and(0.059±0.009)h^-1 to(0.018±0.001)h^-1 and(0.042±0.002)h^-1 and PNP removal rate decreased 36%and 6.9%with carbon switchover.The PNP degradation rate constant of RNaHCO3 and RGlucose decreased to(0.004±0.00061)h^-1 and(0.007±0.0006)h^-1 respectively when the applied voltage was converted from 0.5 V to 0 V,and the PNP degradation rate constant increased to(0.022±0.002)h^-1 and(0.062±0.004)h^-1 when the applied voltage was converted to 0.5 V again.Microbial community structures of biocathode were significantly different with different carbon source.Proteobacteria was the dominant bacteria in the sodium bicarbonate reactors,Firmicutes and Bacteroidetes were the predominant bacteria in the glucose reactors.This study showed the base technology of PNP degradation in the future.