进水COD浓度对基于MFC的UASB生物传感器反馈性能的影响

Influence of COD conditions on feedback characteristics of upflow anaerobic sludge bed reactor biosensor based on microbial fuel cell

考察MFC生物传感器在不同COD负荷条件下电信号的反馈情况.通过对比不同进水COD条件下的反馈时间,研究pH对MFC传感器反馈性能的影响.实验结果表明：MFC电信号与进水COD质量浓度具有良好的线性关系;在1000-3000mg/L的进水条件下,MFC稳定电压与进水COD质量浓度呈y=3.83×10^-5x＋0.25的线性增长关系,传感器的反馈时间为4h;随着进水COD质量浓度提升至4000-6000mg/L,MFC稳定电压与进水COD质量浓度呈y=-5.95×10^-5x＋0.54的线性下降关系,系统内挥发性脂肪酸大量积累导致pH降至4.6,反馈时间延缓至8.6h,系统长期处于酸化状态,产电微生物活性降低,电子传递速率受到抑制,传感器反馈时间延迟.

The performance of electrical signal feedback of microbial fuel cell （MFC） -based biosensor in different COD condition was explored. The effect of pH on the feedback of MFC-based biosensor was studied by comparing the feedback time between the different COD condition. Results showed that the linear correlation between voltage and COD concentration was established. The feedback time was 4 h and the voltage increased linearly by y = 3.83×10^-5x ＋ 0.25 with COD from 1 000 mg/L to 3 000 mg/L. The feedback time delayed to 8.6 h and pH declined to 4.6 simultaneously according to the accumulation of volatile fatty acid in the reactor with COD concentration and the voltage decreased linearly by y = -5.95×10^-5x ＋ 0.54 with COD increasing from 4 000 mg/L to 6 000 mg/ L. In consequence, the activity of electrogenesis microorganism decreased and the electron transfer rate was re - strained due to the acidic of this system. The feedback time of the MFC-based biosensor was put off as a result.