重金属污染土壤电动力学修复技术

电动力学修复技术是把电极插入受污染的土壤并通入直流电 ,发生土壤孔隙水和带电离子的迁移。土壤中的污染物质在外加电扬作用下发生定向移动并在电极附近累积 ,抽出处理从而被除去。新兴的电动力学原位修复技术去除土壤重金属污染正越来越多地被各国研究人员接受。一系列实验规模的研究和技术已日渐成熟 ,其中Lasagna技术和Electro klean技术已在美国肯塔基州和路易斯安那州等地进行了原位修复     

Photo-induced surface frustrated Lewis pairs for promoted photocatalytic decomposition of perfluorooctanoic acid

● Terminal carboxylate group activation is PFOA degradation’s rate-limiting step. ● Bi₃O(OH)(PO₄)₂ with surface frustrated Lewis pairs (SFLPs) efficiently degrade PFOA. ● Photo-induced Lewis acidic sites and proximal surface hydroxyls constitute SFLPs. ● SFLPs act as collection centers to effectively adsorb PFOA. ● SFLPs endow accessible pathways for photogenerated holes rapid transfer to PFOA. Heterogeneous photocatalysis has gained substantial research interest in treating per- and polyfluoroalkyl substances (PFAS)-contaminated water. However, sluggish degradation kinetics and low defluorination efficiency compromise their practical applications. Here, we report a superior photocatalyst, defected Bi₃O(OH)(PO₄)₂, which could effectively degrade typical PFAS, perfluorooctanoic acid (PFOA), with high defluorination efficiency. The UV light irradiation could in situ generate oxygen vacancies on Bi₃O(OH)(PO₄)₂ through oxidation of the lattice hydroxyls, which further promotes the formation of Lewis acidic coordinately unsaturated bismuth sites. Then, the Lewis acidic sites couple with the proximal surface hydroxyls to constitute the surface frustrated Lewis pairs (SFLPs). With the in-depth spectroscopic analysis, we revealed that the photo-induced SFLPs act as collection centers to effectively adsorb PFOA and endow accessible pathways to transfer photogenerated holes to PFOA rapidly. Consequently, activation of the terminal carboxyl, a rate-limiting step for PFOA decomposition, could be easily achieved over the defected Bi₃O(OH)(PO₄)₂ photocatalyst. These results suggest that SFLPs exhibit great potential in developing highly efficient photocatalysts to degrade persistent organic pollutants.     

生物炭固定化菌复合材料在环境修复中的应用研究进展

随着工业和农业的快速发展,环境污染日益严重,对生态安全和人体健康形成严重威胁.微生物修复是一种低价、绿色和易操作的技术,但微生物对高浓度污染物耐性低,造成修复效果差和周期长.由于生物炭的孔隙率高、官能团丰富和比表面积大,被认为是一种良好的吸附剂和固定化载体.通过微生物固定化技术将菌群定殖于生物炭上而制备生物炭固定化菌复合材料,结合了二者优势又克服菌群的缺点,展现了巨大的应用前景.通过系统论述生物炭固定化菌复合材料的制备方法和特征,评价生物炭固定化菌复合材料在环境修复中的效能,讨论环境因素对生物炭固定化菌复合材料去除水中污染物和修复污染土壤的效果影响,阐明生物炭固定化菌复合材料对废水处理与土壤修复的作用机制.     

The Ecotoxicological Recovery of Ely Creek and Tributaries (Lee County, Va) After Remediation of Acid Mine Drainage

The Ely Creek watershed (Lee County, VA) was determined in 1995 to be the most negatively affected by acid mine drainage (AMD) within the Virginia coalfield. This determination led the US Army Corps of Engineers to design and build passive wetland remediation systems at two major AMD seeps affecting Ely Creek. This study was undertaken to determine if ecological recovery had occurred in Ely Creek. The results indicate that remediation had a positive effect on all monitoring sites downstream of the remediated AMD seeps. At the site most impacted by AMD, mean pH was 2.93 prior to remediation and improved to 7.14 in 2004. Benthic macroinvertebrate surveys revealed that one AMD influenced site had increased taxa richness from zero taxa in 1997 to 24 in 2004. While in situ testing of Asian clams resulted in zero survival at five of seven AMD influenced sites prior to remediation, some clams survived at all sites after. Clam survival was found to be significantly less than upstream references at only two sites, both downstream of un-mitigated AMD seeps in 2004. An ecotoxicological rating (ETR) system that combined ten biotic and abiotic parameters was developed as an indicator of the ecological status for each study site. A comparison of ETRs from before and after remediation demonstrated that all sites downstream of the remediation had experienced some level of recovery. Although the remediation has improved the ecological health of Ely Creek, un-mitigated AMD discharges are still negatively impacting the watershed.     

Availability and Assessment of Fixing Additives for The in Situ Remediation of Heavy Metal Contaminated Soils: A Review

The use of low-cost and environmental safety amendments for the in situ immobilization of heavy metals has been investigated as a promising method for contaminated soil remediation. Natural materials and waste products from certain industries with high captive capacity of heavy metals can be obtained and employed. Reduction of extractable metal concentration and phytotoxicity could be evaluated and demonstrated by the feasibility of various amendments in fixing remediation. In this review, an extensive list of references has been compiled to provide a summary of information on a wide range of potentially amendment resources, including organic, inorganic and combined organic-inorganic materials. The assessment based on the economic efficiency and environmental risks brought forth the potential application values and future development directions of this method on solving the soil contamination.     

污染场地修复工程环境监理的实践与探索

环境监理是污染场地修复过程中不可或缺的关键环节,在我国起步相对较晚,可供借鉴的实例很少。以苏州市某化工厂遗留场地污染土壤和地下水修复工程为例,阐述了不同阶段环境监理的工作内容,突出了原位和异位修复技术的环境监理工作要点,并提出建立污染土壤和地下水修复效果质量控制体系和原位修复效果长期跟踪监测机制等建议。     

两种修复模式下CAHs污染地下水的原位对照

为探究氯代脂肪烃（CAHs）污染地下水原位修复的长效性及环境的长期响应，选择华北某废弃化工厂污染区，开展了生物刺激、零价铁（ZVI）-生物刺激耦合中试对照试验，系统对比了2种修复模式下CAHs的降解效率及地下水生物化学参数的动态变化规律.结果表明，修复后长达4~5a内总CAHs含量均降至50 μg/L以下，耦合修复策略提高了CAHs的整体降解效率且未出现浓度反弹，同时可更快速地改善地下环境，为潜在降解菌的生长提供有利条件.两种修复方式对地下水细菌多样性的长期影响基本一致，均有利于向脱硫菌门Desulfobacterota和绿弯菌门Chloroflexi演化.最终生物刺激区总细菌数量高于耦合修复区约1个数量级，但后者地下水中的脱卤球菌属Dehalococcoidia数量（2.1~35）×10³copies/mL反而高于前者（8.3~9.1）×10³copies/mL，这更有利于CAHs的彻底脱氯.     

地表环境汞污染的生物修复技术及展望

汞（Hg）及其化合物是一类重要的全球污染物，环境中高浓度的汞会对生态系统和人类健康造成严重危害。《关于汞的水俣公约》正式生效后，汞生产量、使用量和排放量将得到有效控制。然而历史排放汞导致的污染问题依然会对自然环境造成长期的生态风险，因此在减排的同时也亟需开发、发展有效治理汞污染的方法。本文总结了汞污染生物修复的技术及应用原理，分析了基于生物修复原理运用合成生物学手段改造生物将其运用到汞污染修复的优势和潜力，最后探讨了汞污染合成生物学修复应重点关注的问题和前沿研究方向。