Bioelectrochemical Sensor Using Living Biofilm To in Situ Evaluate Flocculant Toxicity
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- 作者：Tian Li ; Xin Wang ; Lean Zhou ; Jingkun An ; Junhui Li ; Nan Li ; Hongwen Sun ; Qixing Zhou
- 刊名：ACS Sensor
- 出版年：2016
- 出版时间：November 23, 2016
- 年：2016
- 卷：1
- 期：11
- 页码：1374-1379
- 全文大小：587K
- ISSN：2379-3694
文摘
Flocculants have been used to clarify water for thousands of years. However, the in situ evaluation of flocculant toxicity is difficult because flocculants usually exist as growing complex flocs which is hard to monitor. With alum (KAl(SO4)2·12H2O) as the typical flocculant, a bioelectrochemical sensor is designed to in situ detect its bacterial toxicity. The attenuation ratio of current densities linearly increased with alum concentration (R2 > 0.98) with a slope of 0.0054 A m–2 drop per mg L–1 of alum, indicating a typical toxic response of alum. Turnover and nonturnover cyclic voltammetries (CVs) revealed that the alum inhibited the electrochemical activity of bacteria rather than changing the electron transfer pathways. Alum also hindered the diffusion by flocculation at a concentration larger than 100 mg L–1, which was further confirmed by the linear decrease in viability when biofilm thickness increased. It was revealed that both inactivation of biofilm and influences on diffusion by alum can be detected by bioelectrochemical sensors, which provided a new platform to in situ investigate the biological toxicity of new flocculants.