土壤镉和砷污染钝化修复材料及科学计量研究

使用Web of Science(WOS)核心合集数据库统计了5年内(2014—2018年)关于土壤镉(Cd)和砷(As)单一污染的情况,发现土壤Cd和As污染依然受到人们的广泛关注,且我国在该领域发文最多。利用CiteSpace软件分析发现施用钝化修复材料是土壤Cd和As污染治理的热点修复技术之一。基于此,本文综述了常见的钝化修复材料及其钝化机理,并分别对钝化修复材料的室内研究和修复实践进行总结,发现无机类钝化修复材料中石灰类主要通过调节土壤pH值改变重金属有效性;磷酸盐类分别通过共沉淀和点位竞争机制钝化重金属;金属及其氧化物类通过表面络合和还原作用对重金属的钝化效果更好;黏土矿物中海泡石和坡缕石廉价绿色且具有较大的比表面积,对重金属的钝化效果较好。有机类钝化剂中生物炭类为研究热点材料之一,因表面拥有丰富的官能团和较大的比表面积,其对重金属表现出良好的钝化修复效果;有机废弃物含高度腐殖化的有机质和微生物,对重金属钝化效果较好。此外,对国内外典型的Cd和As污染实践修复工程进行介绍,发现金属及其氧化物、堆肥、生物炭以及廉价易获得的石灰和黏土矿物施用较广。最后,讨论了钝化修复材料施用中亟需解决的问题。

Immobilization materials for cadmium and arsenic contaminated soil remediation and their scientific metrology research

This paper used the Web of Science (WOS)core collection database to gather statistics on soil cadmium and arsenic single contamination during 2014 to 2018. It was found that cadmium and arsenic contamination in soil were still widely concerned, and China published the most articles in this field. By using CiteSpace software, we found that application of immobilization materials was one of the most popular technologies for soil cadmium and arsenic remediation. Based on this, this paper summarized the common immobilization materials and mechanism, and the indoor research and remediation practice related to immobilization materials were summarized, respectively. For inorganic immobilization materials, lime changes the effectiveness of heavy metals mainly by regulating soil pH; phosphates immobilize heavy metal through co-precipitation and site competition mechanism; metal oxides showed a good remediation effect on heavy metal by surface complexation and reduction; sepiolite and palygorskite were cheap and green, and had large specific surface areas, and showed significant amendment effect on heavy metal. For organic immobilization materials, biochar shows significant immobilization effect on heavy metal due to its rich functional group and high surface area. Organic waste contained large quantity of humic substances, organic matter, and microorganisms, and showed significant effect on heavy metal immobilization. In addition, the typical field remediation projects of cadmium/arsenic contaminated soil in China and other areas of the world were introduced. Overall, it is found that the metal and its oxides, compost, biochar, lime and clay minerals are applied widely in the world. To provide the guidance for cadmium and arsenic contaminated soil remediation, we finally discussed the urgent problems that need to be solved in the application of immobilization materials.