阳极石墨毡酸处理对微生物燃料电池型BOD传感器性能的影响

Effect of nitric acid treatment of anode material on performances of microbial fuel cell-based BOD sensor

通过石墨毡表面润湿性的变化,确定了硝酸酸化处理石墨毡的操作条件。采用硝酸处理后的石墨毡作为电极材料,构建双室无介体微生物燃料电池（microbial fuel cell,MFC）型BOD传感器,并对BOD传感器的性能进行评价。结果表明,硝酸酸化处理明显提高石墨毡表面的润湿性,经过4 h酸化处理,石墨毡的表面接触角由142.5°下降到86.5°。采用硝酸处理的石墨毡作为电极材料,MFC的电流输出明显提高且稳定,在响应时间小于10 h条件下,废水BOD检测上限为100 mg/L。废水BOD浓度在2-50 mg/L范围内,可以利用BOD浓度与电流最大值之间的线性关系进行废水BOD浓度检测,废水BOD浓度在2-100 mg/L范围内,可以利用BOD浓度与电荷量之间的线性关系对废水BOD浓度进行检测,检测相对误差均在12%以下。MFC型BOD传感器运行稳定,相对标准偏差均在10%以下。

The operating conditions for nitric acid treatment of graphite felt were determined by comparing wettability. A mediator-less double-chamber microbial fuel cell（ MFC） was constructed as BOD sensor with acidtreated graphite felt as the electrode material,and the performance of the BOD sensor was evaluated. The results showed that nitric acid treatment significantly improved the wettability of the graphite felt,and that the watercontact angle of the graphite felt decreased from 142. 5° to 86. 5° after nitric acid treatment for 4 h. The output current of MFC obviously increased and remained stable with the acid-treated graphite felt. With response time 〈10 h,the upper limit of detection of the BOD sensor was 100 mg / L. The BOD concentration could be detected based on the linear correlation between BOD concentration and maximum current within the range from 2 to 50 mg / L. When the BOD concentration ranged from 2 to 100 mg / L,the BOD concentration could be detected based on the linear correlation between BOD concentration and charge generation. The relative error was 〈12%. The MFC-based BOD sensor operated stably with a long life,and the relative standard deviation was 〈10%.