Abstract:

The pollution of heavy metals in soil is a serious problem in China. In this work, a way of collaborative harmless treatment disposal and resource utilization of heavy metal polluted hazardous soil was proposed. It was found that the addition of attapulgite and auxiliary materials can transform the hazardous solid waste to general solid waste, and pretreated soil could be further utilized as the feed for ceramsite production. Under optimized conditions, more than 50%, 66%, 59% and 52% content of lead, chromium, copper and zinc in the contaminated soil could be stabilized when 4% (mass fraction) attapulgite was added in 48h. After that, the pretreated solid waste was calcined in a continuous rotary kiln to ceramsite, and the content of Pb and Cd emitted during ceramsite production is lower than the control requirements of emission limit.

Key words: soil, restoration, resource, ceramsite

摘要：

在中国，土壤中的重金属污染问题形势严峻，本文探索了一条采用先将重金属污染土壤中铅、镉、铜、锌固定再利用回转窑协同处置并资源化利用的技术途径。实验发现：添加适量的凹土及稳定化试剂并经稳定化处理以后，可以实现污染土壤由危险废物向一般固废的转变；进一步将稳定化处理后的土壤采用回转窑深度加工、能生产得到安全指标和产品性能合格的陶粒。经过优化实验方案后的结果显示，在铅、镉、铜、锌等重金属初始含量（上限）为2280mg/kg、592mg/kg、2000mg/kg、93400mg/kg的污染土壤添加4%的凹土（质量分数）及其他辅助材料后稳定化48h，上述重金属的可溶态检出量分别降低了50%、66%、59%、52%，经治理后的土壤可以转变为一般固废。用这种固定化处理后的土壤可以生产出合格的陶粒，而且在陶粒生产过程中逸散排放的铅、镉含量均低于大气污染物排放限制要求。

关键词: 土壤, 修复, 资源化, 陶粒