• 关键词：沉积物微生物燃料电池  重金属污染  连续监测  电压信号  产电细菌

• 基金项目：国家自然科学基金项目（No.41671250，41877425）；江苏省自然科学基金面上项目（No.BK20171476）

• 刘丽
• 1. 南京师范大学环境学院, 南京 210023;2. 江苏省物质循环与污染控制重点实验室, 南京 210023

• 吴少松
• 1. 南京师范大学环境学院, 南京 210023;2. 江苏省物质循环与污染控制重点实验室, 南京 210023

• 杨楚瑶
• 南京师范大学环境学院, 南京 210023

• 钟文辉
• 2. 江苏省物质循环与污染控制重点实验室, 南京 210023;3. 南京师范大学地理科学学院, 南京 210023

• 孟梁
• 上海市环境科学研究院, 上海 200000

• 邓欢
• 1. 南京师范大学环境学院, 南京 210023;2. 江苏省物质循环与污染控制重点实验室, 南京 210023

• 摘要：本研究考察了一种自主研发的新型沉积物微生物燃料电池传感器（命名为DH-I型SMFC传感器）产电信号对连续多次Cd²⁺污染事件的响应特征.采用淹水土壤模拟湿地环境，将该传感器的阳极（不锈钢管）插入淹水土壤中，阴极（铂网）位于上覆水下方.分别向每个传感器阴极上方的上覆水中加入50 mL Cd²⁺浓度为25、50、100、200 mg·L^-1的CdCl₂溶液，对照加入50 mL去离子水.每天早晚各加入一次Cd²⁺污染，连续加入27 d，即每个传感器各加入53次相同浓度的CdCl₂溶液.结果表明，每次加入Cd²⁺污染后，电压均迅速上升，在30 s内达到峰值后逐渐回落到稳定状态；并且电压增量（峰值电压与基线电压的差值）随着加入的Cd²⁺浓度增加而升高；而相同Cd²⁺浓度53次加入引起的电压增量具有较好的一致性.土壤产电细菌的代表类群地杆菌科（Geobacteraceae）和梭菌属（Clostridium）16S rRNA基因丰度均未随着Cd²⁺浓度的增加而降低.针对土壤中不同形态Cd²⁺浓度的检测结果表明，0~3 cm的表层土壤吸附了大量Cd²⁺，使得土壤中的产电细菌免受Cd²⁺的抑制，从而该传感器产电信号能够在湿地环境中，原位在线监测多次Cd²⁺污染.

• Abstract：A novel sediment microbial fuel cell (SMFC) based sensor (DH-I type SMFC sensor) was developed to study the response of electrical signals to repeated Cd²⁺ pollution. Soil was flooded with water to simulate wetland. The anode (stainless steel tube) of the sensors were inserted into the flooded soil, and the cathode (platinum mesh) was located beneath the overlying water. In five sensors, 50 ml CdCl₂ solution with 25, 50, 100 and 200 mg·L^-1 Cd²⁺, and deionized water as control were added to the overlying water. For each sensor, CdCl₂ solution was supplemented for twice a day in consecutive 27 days, with a total of 53 times. The results show that the voltage increased rapidly with each addition of Cd²⁺ and reached a peak within 30 s, then gradually decreased to a stable state. With the increase of Cd²⁺ concentration, the voltage increments (the difference between peak voltage and baseline voltage) increased. The voltage increments were similar among every CdCl₂ addition. The 16S rRNA gene abundance of Geobacteraceae and Clostridium, which were the representative of exoelectrogenic bacteria, did not decrease with the increase of Cd²⁺ concentration. The results of different forms of Cd²⁺ in soil show that a large amount of Cd²⁺ was adsorbed in the surface soil (0~3 cm), which protected the exoelectrogenic bacteria in soil from being inhibited by Cd²⁺. We suggest that the electrical signals of sensors could be used in situ and on line monitoring the events of heavy metal pollution in wetlands.

• Key words：sediment microbial fuel cells  heavy metal pollution  continuous monitoring  voltage signal  exoelectrogenic bacteria

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