梁仲哲++齐绍武++和七红

摘 要：化肥、农药大量施用以及工业废物的排放导致重金属源源不断地排放到环境中，重金属具有不易降解性，对人类健康和环境保护造成严重影响。通过施加改良剂对土壤重金属进行固定或钝化， 该方法因易操作、实用值高等特点得以广泛应用。目前，改良剂主要有有机物、碱性物质以及粘土矿物等几类。改良剂能有效降低土壤pH值，提高改良剂与重金属的吸附、络合以及沉淀作用。对重金属污染较重的土壤，单施改良剂效果不显著，利用不同性质的物化改良剂混合搭配成的复合改良剂可以提高土壤改良和重金属钝化的效果。

关键词：重金属；土壤改良；改良剂

中图分类号：X53 文献标识码：A DOI 编码：10.3969/j.issn.1006-6500.2016.07.002

Abstract： The application of pesticide， fertilizer and industrial waste emission result in heavy metals to the environment. And it`s hard to transfer by food chain and also not easy to degradation. So it caused serious influence to human and environmental. The method of fixing and passivation of heavy metals in soil by applying the modifier is widely used because of its simple operation and economical and practical characteristics. At present， the improved agent types mainly include organic matter， alkaline substances， and clay minerals. The effect of the improved agent was mainly derived from the soil pH and the adsorption， complexation and precipitation of the modified agent itself and heavy metals. In the region where the soil heavy metal pollution is serious， the effect of the application of single modified agents is not very ideal， using the modified agent mixed with different agent can increase the effect to a certain extent.

Key words： heavy metal；soil improvement；improvement agent

1 土壤重金属污染途径

随着工业化进程的逐步深入，农业发展加速，废弃物逐步增多且相关处理措施不当，这导致农田中土壤重金属含量逐步增加。农业部曾对全国土壤调查发现，重金属超标农产品占污染物超标农产品总面积80%以上[1]，土壤重金属超标率更是达到了12.1%[2]。据国外相关研究得知，土壤重金属含量已经达到影响作物生长的地步[3-4]。而龙新宪等人的研究发现：土壤重金属离子含量达到一定程度，这些重金属离子将通过被植物吸收而进入食物链，最终威胁人类身体健康[5-7]。同时，重金属污染的表层土还会通过风力和水力等作用进入大气引发大气污染、地表水污染等生态环境问题[8]。

1.1 大气运动

大气运动是土壤重金属污染来源的一个重要途径[9]。……