用于水环境重金属监测的微生物电化学传感器构建与运行效果分析

Construction and performance analysis of a microbial electrochemical sensor for monitoring heavy metals in water environment

本研究旨在开发基于微生物燃料电池(microbial fuel cell,MFC)的微生物电化学传感器对水环境重金属污染进行实时在线监测。构建微生物电化学传感器,采用错流式布水方式、优化外阻值及外循环速率等参数,在最优参数下分析重金属模拟废水浓度对电压的抑制情况。结果表明,当外阻值为130Ω、外循环速率为1.0 mL/min时,MFC电化学传感器的性能最优。在此条件下对1–10 mg/L的Cu^(2+)、0.25–1.25 mg/L的Cd^(2+)、0.25–1.25 mg/L的Cr^(6+)和0.25–1.00 mg/L的Hg^(2+)均有响应,60 min内输出电压最大抑制率分别可达92.95%、73.11%、82.76%和75.80%,线性相关系数均大于0.95,且有较好的生物学重复性。该MFC电化学传感器具有良好的重金属检测性能,可为实现水环境重金属污染实时在线监测技术的实际应用提供理论依据。

A microbial fuel cell(MFC)-based microbial electrochemical sensor was developed for real-time on-line monitoring of heavy metals in water environment.The microbial electrochemical sensor was constructed with staggered flow distribution method to optimize the parameters such as external resistance value and external circulation rate.The inhibition of concentration of simulated heavy metal wastewater on voltage under optimal parameters was analyzed.The results showed that the best performance of MFC electrochemical sensor was achieved when the external resistance value was 130Ω and the external circulation rate was 1.0 mL/min.In this case,the microbial electrochemical sensors were responsive to 1–10 mg/L Cu^(2+),0.25–1.25 mg/L Cd^(2+),0.25–1.25 mg/L Cr^(6+)and 0.25–1.00 mg/L Hg^(2+)within 60 minutes.The maximum rejection rates of the output voltage were 92.95%,73.11%,82.76%and 75.80%,respectively,and the linear correlation coefficients were all greater than 0.95.In addition,the microbial electrochemical sensor showed a good biological reproducibility.The good performance for detecting heavy metals by the newly developed microbial electrochemical sensor may facilitate the real-time on-line monitoring of heavy metals in water environment.