摘要
发展新型绿色、高效、低能耗和可持续的微生物修复技术用于处理氯代烯烃污染十分必要.专性有机卤化物呼吸菌能专一高效地去除氯代有机污染物,但在实际修复过程中电子供体如氢气的不足限制了其应用,因此寻找合适的供氢方式十分重要.利用光催化水解产氢为微生物提供电子供体可能是一种理想方式,然而国内外尚未有半人工光合系统驱动微生物脱卤呼吸的相关研究.本文利用脱卤拟球菌Dehalococcoides mccartyi菌株195(Dhc195)与硼掺杂石墨相氮化碳纳米片构建了B-C3N4-NS-Dhc195生物杂化体系,探究可见光驱动其对三氯乙烯(TCE)进行厌氧还原脱氯的可行性.研究结果表明,在(25±5) W m^(-2)的低强度可见光下该生物杂化体系可持续稳定地将TCE逐步还原脱氯至乙烯(ETH),脱氯速率为(1.13±0.13)μmol L^(-1)d^(-1);该杂化体系内检测到氢气生成,对Dhc195脱氯的用氢量进行衡算,其氢气利用率达84%.这表明可见光下光催化剂分解水产氢,脱氯菌利用氢气作为电子供体还原TCE,从而实现可见光驱动微生物脱卤呼吸.本研究提出了一种间接利用光能实现微生物处理氯代有机污染物的方法,对氯代有机污染物的绿色、低碳、可持续治理和修复具有启发意义.
Chlorinated organic pollutants, especially chlorinated ethenes, are widely found in contaminated subsurface soils and groundwater, posing great threats to human health and ecosystems. Therefore, it is of great priority to develop a green,effective, energy-saving as well as sustainable technology for chlorinated ethenes degradation, and microbial-catalyzed reductive remediation is a promising orientation. Obligate organohalide-respiring bacteria, such as Dehalococcoides,utilize halogenated organic compounds as terminal electron acceptors and are considered to be crucial from both viewpoints of natural attenuation and engineered bioremediation. But the shortage of electron donors such as hydrogen in the actual remediation process limits its application, which makes it significantly important to find a new and suitable hydrogen supply method. Photocatalytic water splitting is an emerging technology that has been recently used for hydrogen production, which may be an ideal way to provide electron donors for microorganisms. In recent years, the microbephotocatalyst hybrids, serving as a semi-artificial photosynthetic system, have received extensive attention. In this study,the B-g-C_(3)N_(4)nanosheet(B-C_(3)N_(4)-NS) photocatalyst was prepared through boron doped and structure modification and was combined with the dechlorinating bacterium Dehalococcoides mccartyi 195(Dhc195). The B-C3N4-NS-Dhc195 biohybrid system was constructed to assess the feasibility of visible light-driven reductive dichlorination of the pollutant trichloroethylene(TCE). The biohybrid system was characterized by SEM, and the TCE concentration, possible dechlorination products and H2concentration were measured. The SEM images showed that Dhc195 was tightly attached to the photocatalyst. It was discovered that the TCE concentration decreased in the biohybrid system under the lowintensity visible light of(25±5) W m^(-2). The dechlorination rate was measured to be(1.13±0.13) μmol L^(-1)d^(-1). The transformation products such as cis-1,2-dichloroethylene(cis-DCE), vinyl chloride(VC), and ethene(ETH) were observed, indicating that the biohybrid system could gradually dechlorinate TCE to ETH without exogenous hydrogen. The generation of hydrogen was detected, and the utilization rate reached 84% through calculating the hydrogen consumption of microbial dechlorination process. Taken together, in this hybrid system, the dechlorination mechanism was that the photocatalyst split water under visible light to produce hydrogen, which the dechlorination bacteria used as electron donor for reductive dechlorination with chlorinated ethenes as the terminal electron acceptor and reductive dehalogenase(RDase)as the key enzyme involved. A visible light-driven microbial reductive dehalogenation system was successfully realized and established. This study creatively proposes a new method for microbial treatment of chlorinated organic pollutants by the indirect use of solar energy, which provides new insights into the development of the green, low-carbon, and sustainable treatment and remediation of chlorinated organic pollutants.
作者
唐晴
唐麒君
羊家威
陈柯蓁
王海强
沈超峰
Qing Tang;Qijun Tang;Jiawei Yang;Kezhen Chen;Haiqiang Wang;Chaofeng Shen(College of Environmental and Resource Seience,Zhejiang University,Hangzhou 310058,China;Zhejiang Provincial Key Laboratory for Water Pollution Control and Environmental Safety Technology,Hangzhou 310058,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2022年第34期4108-4115,共8页
Chinese Science Bulletin
基金
浙江省“尖兵”研发攻关计划(2022C03010)
浙江省重大科技专项(2021C03167)资助。
关键词
光催化
三氯乙烯
脱卤拟球菌
还原脱氯
生物杂化体系
photocatalysis
trichloroethene
Dehalococcoides
reductive dichlorination
biohybrid system
