周政,胡锋平,魏朝成,王艺,戴红玲,徐磊,俞文正.生物电耦合对活性炭-超滤工艺处理地表微污染水的影响机理研究[J].环境科学学报,2020,40(7):2427-2437
生物电耦合对活性炭-超滤工艺处理地表微污染水的影响机理研究
- Influence of bioelectrical integrated activated carbon-ultrafiltration system for micro-polluted surface water treatment
- 基金项目：国家自然科学基金（No.51908537，51108444）；江西省自然科学基金（No.20181BAB206037，20192BAB206038）
- 周政
- 1. 华东交通大学土木建筑学院, 南昌 330013;2. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 胡锋平
- 华东交通大学土木建筑学院, 南昌 330013
- 魏朝成
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 王艺
- 华东交通大学土木建筑学院, 南昌 330013
- 戴红玲
- 华东交通大学土木建筑学院, 南昌 330013
- 徐磊
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 俞文正
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 摘要：利用生物电化学系统处理地表水时，弱电压不但会刺激电活性菌的呼吸作用，而且会引起氧化胁迫导致胞外聚合物（Extracellular Polymeric Substance，EPS）过量分泌.为确认在地表水处理中弱电压对膜污染和净水效率的影响，本研究设置了外加1.0 V直流电压（记为"BES系统"）和无外加电压（记为"CK系统"）的两组平行对照生物活性炭-超滤系统.经过50 d的运行，BES系统（36.1 kPa）相比CK系统（19.1 kPa）跨膜压差（Trans Membrane Pressure，TMP）增加更为显著，膜污染更严重.电路电流、电极电势和循环伏安（Cyclic Voltammetry，CV）曲线显示，随着装置运行，两系统生物膜逐渐稳定，并且产生具有氧化还原活性的EPS导致阳极电容增加.相比之下，BES系统产生了更多EPS，具有更高的阳极电容.水质指标显示，BES系统中比紫外吸光度（Specific Ultraviolet Absorbance，SUVA）、NH4+-N和PO43--P的去除增强但总有机碳（Total Organic Carbon，TOC）去除减弱；三维荧光光谱（Excitation-Emission-Matrix，EEM）和尺寸排阻色谱（Size Exclusion Chromatography，SEC）分析结果表明，BES系统膜池中产生了更多的生物聚合物，但腐殖质类有机物明显减少.活性炭表面EPS含量和腺嘌呤核苷三磷酸（Adenosine Triphosphate，ATP）含量的测试结果证实，弱电压刺激了生物膜的生长，同时增加了氧化还原活性EPS的含量.对膜表面累积多糖、蛋白质含量的测试分析进一步揭示了多糖类大分子生物聚合物在膜表面的累积是导致严重膜污染的直接原因.研究可为生物电化学系统在微污染水处理的研究和应用提供新的见解.
- Abstract：A low voltage in bioelectrochemical system treating surface water not only stimulates the respiration of the electro-active microbes, but also induces oxidative stress along with the secretion of excessive amounts of extracellular polymeric substances (EPS). In this study, two parallel biological activated carbon integrated ultrafiltration systems were installed to identify the influence of low voltage on membrane fouling development and treatment efficiency while treating surface water. One of the systems was supplied with an external direct voltage of 1.0 V (termed as "BES") and the other one without voltage supply was termed as "CK". After 50 days of filtration operation, an increased Trans membrane pressure (TMP) profile (i.e. 36.1 kPa) was observed for the BES, indicating in a severe membrane fouling comparing to the CK system (19.1 kPa). Results of the circuit current, electrode potentials, and cyclic voltammetry (CV) curves revealed that the biofilms of the two systems were gradually stabilized along with the operation and the production of EPS with redox activity led to an increased anodic capacitance. In contrast with the CK system, a higher EPS production was observed for the BES, resulting in a higher anodic capacitance. Water quality parameters showed that the removal of specific ultraviolet absorbance (SUVA), NH4+-N and PO43--P increased along with the decrease of total organic carbon (TOC) in the BES. Additionally, the excitation-emission matrix (EEM) and size exclusion chromatography (SEC) analysis indicated that more biopolymers were produced within the membrane tank of the BES, while the concentration of humic organic compounds decreased significantly. EPS and adenosine triphosphate (ATP) contents on activated carbon surface confirmed the stimulated growth rate of biofilm because of the low voltage along with an increased amount of redox-active EPS. Further analysis of the accumulated polysaccharides and proteins on the membrane surface revealed that the macromolecular biopolymers (i.e. polysaccharides) cause severe membrane fouling. This study provides some insights into the applications of the bioelectrochemical system treating micro-polluted surface water.
