电性矿物强化脱氯菌对水中TCE的降解  

Degradation of TCE in Water by Electrical Mineral Enhanced Dechlorination Bacteria

作　　者：李铁龙[1] 谭鹏 王薇[1,2] Li Tielong;Tan Peng;Wang Wei(College of Environmental Science and Engineering,Nankai University,Tianjin 300350,China;Nankai University Cangzhou Bohai New Area Institute of Green Chemical Engineering,Cangzhou 061108,China)

机构地区：[1]南开大学环境科学与工程学院,天津300350 [2]南开大学沧州渤海新区绿色化工研究院,沧州061108

出　　处：《天津大学学报（自然科学与工程技术版）》2023年第11期1177-1186,共10页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(22036004);国家重点研发计划资助项目(2018YFC1802002);天津市自然科学基金资助项目(19JCYBJC23400);南开大学沧州渤海新区绿色化工研究院基金项目.

摘　　要：针对地下水环境中脱氯菌污染修复周期长、电子供给难度大、易带来二次污染等问题,设计以天然矿物电气石的电场刺激、水解供氢和水体调节性能强化含脱卤拟球菌(Dehalococcoides spp.)的混合脱氯菌功能,通过将电气石和脱氯菌共同固定化,开发适用于地下水环境的生物强化原位修复技术.研究了共同包埋的电气石和脱氯菌对地下水典型有机污染物三氯乙烯(TCE)的降解性能.结果表明,在包埋材料海藻酸钠含量6%、凝固剂氯化钙含量6%、电气石含量1.0%、交联时间24 h条件下制得的固定化微球弹性好,机械强度高,粒径均匀分布在3~5 mm,具有多孔洞内结构和较为致密的外表面,既可提供电气石和细菌附着的场所,又能有效地防止微球内部菌体的流失.同时,包埋后的电气石仍能快速调节水体的pH和ORP,为厌氧脱氯菌提供适宜的生长代谢环境.无论是固定化还是分离体系,电气石的加入均增强了脱氯菌对TCE的还原脱氯效果,而电气石-脱氯菌共同固定化体系不仅能加快TCE的降解,在无外加电子供体的情况下仅180 h即可将16 mg/L的TCE完全去除,还显著促进了中间产物的进一步脱氯,反应800 h时终产物乙烯的转化率达到64%,比菌体系提升了1倍.电气石对共同包埋的脱氯菌更有效地起到了电场刺激和电子供体的作用,使其快速稳定的增殖.该复合固定化的应用方式促进了脱氯菌的富集及与电气石的接触,更加充分地发挥了电气石表面电场的直接和间接强化作用,可解决实际地下水修复过程中微生物和强化剂易分离失效的问题,促进地下水有机污染原位生物修复技术的发展.Focusing on the problems of long pollution recovery period,difficult electron supply,and secondary pollution in groundwater remediation by dechlorination bacteria,this study aimed to strengthen the function of dechlorination bacteria containing Dehalococcoides spp.by electric field stimulation,hydrolysis hydrogen supply,and water regulation performance of natural mineral tourmaline.By immobilizing tourmaline and dechlorination bacteria together,an enhanced in situ groundwater bioremediation technology was developed.The degradation of trichloroethylene(TCE),a typical organic pollutant in groundwater,by co-entrapped tourmaline and dechlorination bacteria was examined.The experimental results showed that the immobilized microspheres,which were prepared under the conditions of 6%sodium alginate as the embedding material,6%calcium chloride as the coagulant,1.0%tourmaline,and 24 h crosslinking time,have good elasticity,high mechanical strength,and uniform particle size of 3—5 mm.They have a porous inner structure and a relatively dense outer surface,which cannot only provide a place for tourmaline and bacteria to attach but also effectively prevent the loss of bacteria inside the microspheres.Moreover,the embedded tourmaline can still rapidly adjust the pH and oxidation-reduction potential(ORP)of water,providing a suitable growth and metabolic environment for anaerobic dechlorination bacteria.The addition of tourmaline promoted the reductive dechlorination of TCE by the dechlorination bacteria in both the immobilization and separation systems.While the tourmaline-dechlorination bacteria co-immobilized system can not only accelerate TCE degradation,completely removing 16 mg/L TCE in only 180 h without the addition of an electron donor,but also significantly promote the dechlorination of the intermediates.In this system,the conversion rate of the end product ethylene reaches 64%at 800 h,which is twice as high as that of the bacterial system.Tourmaline more effectively applies electric field stimulation and acts as an e

关 键 词：电气石 脱卤拟球菌 固定化 三氯乙烯 产乙烯 

分 类 号：X523[环境科学与工程—环境工程]