【摘要】 多氯联苯(polychlorinated biphenyls,简称PCBs)是一类对环境有不利影响的有毒有机物,它在环境中广泛而大量分布。许多科学家都在致力于有效处理PCBs污染介质(包括水、油、沉积物和土壤)的修复技术的研究。本文综述了国内外在零价金属还原脱氯降解PCBs领域的研究状况。在高温等特殊条件下或有钯、铂、镍和铜等催化剂存在的条件下,零价金属能有效促进PCBs还原脱氯。讨论了零价铁还原脱氯的3个可能的途径:金属直接反应,将零价铁表面的电子转移到有机氯化物使之脱氯;铁腐蚀的直接产物Fe2+具有还原能力,它可使得一部分氯代烃脱氯;铁反应产生的氢气可使有机氯化物还原。评述了零价金属还原脱氯PCBs具有有效、廉价和易得的特点。展望了零价金属还原脱氯降解PCBs研究领域的发展前景。更多还原

【Abstract】 Polychlorinated biphenyls (PCBs) are the toxic organic compounds widely and massively distributed in the environment, and have great environmental impacts. Many scientists endeavored to devise remediation techniques to effectively treat the PCBs-contaminated matrices including water, oil, sediment, and soil. This paper summarized the research progress and development trend of reductive dechlorination of PCBs by zero-valent metal. Zero-valent metal can effectively promote the reductive dechlorination of PCBs under high temperature or the existence of Pd, Pt, Ni and Cu as catalyzers. There are three possible pathways of PCBs dehalogenation by zero-valent metal. The first pathway involves the metal directly, and the reduction occurs by electron transfer from Fe0 surface to the PCBs. The second pathway involves Fe2+, which is an immediate product of corrosion in aqueous systems. Dissolved Fe2+ is a reductant capable of causing PCBs dehalogenation. The third pathway for reductive dehalogenation by iron involves the hydrogen produced as a product of corrosion with water. In this paper, the effective, low-cost, and facile characteristics of PCBs reductive dechlorination by zero-valent metal were commented, and the further research areas were prospected.更多还原