Wang Wei, Liu Xingyu, Li Kerui, Li Tielong
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Tianjin Advanced Water Treatment Technology International Joint Research Center, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Tianjin Advanced Water Treatment Technology International Joint Research Center, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Chemosphere. 2018 Mar;194:9-19. doi: 10.1016/j.chemosphere.2017.11.096. Epub 2017 Nov 20.
Dehalococcoides spp. were extensively studied and applied to in-situ trichloroethylene (TCE) remediation since it is the only genus that can reduce TCE to harmless ethene completely. However, this technology was hindered because of the requirement of electron donor (i.e. hydrogen or fermentable organic substrate). Considering the spontaneous electric field and in-situ hydrogen production capacity of tourmaline, this mineral was used as an environmental-friendly bio-promoter for dechlorinating mixed culture containing Dehalococcoides spp. in this work. Research results showed that biodegradation of TCE and the intermediates were both significantly improved by tourmaline. The first-order TCE degradation rate coefficient increased from 0.0125 h for the tourmaline-free system to 0.0306 h for the system combined with 5 g L tourmaline, and ethene production increased by 36%. The outstanding TCE-degrading ability in the tourmaline-bacteria system without the addition of fermentative electron donor (i.e. methanol) indicated that tourmaline could also produce electron donor to support dechlorinating bacteria. Tourmaline could have direct electric biostimulatory effect and indirect enhanced effect associated with water-derived H production in the electric field of tourmaline. Meanwhile, PCR-DGGE analysis exhibited that tourmaline could accelerate the succession of a bacterial, dechlorinating community. The distinctive effects of tourmaline on bacteria were related to its stable electric properties. Therefore, tourmaline could be continuously used in the bioremediation. The present study provided a safe, convenient and persistent alternative to the commonly used enhancement approaches for anaerobic reductive dechlorination process.
脱卤球菌属已得到广泛研究，并应用于原位三氯乙烯（TCE）修复，因为它是唯一能将TCE完全还原为无害乙烯的属。然而，由于对电子供体（即氢气或可发酵有机底物）的需求，该技术受到了阻碍。考虑到电气石的自发电场和原位产氢能力，在本研究中，这种矿物被用作一种环境友好型生物促进剂，用于对含有脱卤球菌属的混合培养物进行脱氯。研究结果表明，电气石显著提高了TCE及其中间产物的生物降解。一级TCE降解速率系数从无电气石系统的0.0125 h增加到与5 g/L电气石组合系统的0.0306 h，乙烯产量增加了36%。在不添加发酵电子供体（即甲醇）的电气石-细菌系统中，TCE降解能力突出，这表明电气石也可以产生电子供体来支持脱氯细菌。电气石可能具有直接的电生物刺激作用以及与电气石电场中源自水的产氢相关的间接增强作用。同时，PCR-DGGE分析表明，电气石可以加速细菌脱氯群落的演替。电气石对细菌的独特作用与其稳定的电学性质有关。因此，电气石可在生物修复中持续使用。本研究为厌氧还原脱氯过程常用的强化方法提供了一种安全、便捷且持久的替代方法。
