摘要
采用电池企业的场地土壤进行实验,研究了铅污染土壤中混合施加过磷酸钙(C)、膨润土(B)和腐殖酸(H)后对土壤中铅形态及浸出毒性的影响,同时研究了在相同固定剂组合中改变单一固定剂投加量对土壤修复效果的影响。结果表明,(1)经不同配比的C+B、B+H、和H+C组合方式处理后,土壤中铅的有效态质量分数明显降低,而有机结合态和残渣态质量分数增加。固定时间为40 d时,其修复效果优于25 d。修复后土壤的有效态铅大部分转化为有机结合态,其中经过20%B+20%H和10%H+6%C处理后,有效态铅质量分数降低幅度较大,分别从331.3 mg·kg-1降至91.8 mg·kg-1和96.57 mg·kg-1;相应地,有机结合态铅质量分数增加幅度也较大,分别从57.19 mg·kg-1升至264.28 mg·kg-1和267.99 mg·kg-1;(2)C+B组合投加处理中,土壤修复效果随膨润土投加量增加而降低,B+H组合投加处理中,土壤修复效果随着腐殖酸投加量的增加而增加,H+C组合投加处理中,随过磷酸钙投加量增加,土壤修复效果也呈增加趋势。(3)经不同处理固定修复后,土壤浸出液中铅的质量浓度大幅降低,对周周水环境的风险降低。
The Pb-contaminated soil samples were taken from a battery factory located in northern China. The additives including calcium superphosphate （C）, bentonite （B） and/or humic acid （H） were mixed with the contaminated soils to immobilize the Pb in the contaminated soil. To investigate the effects of these additives, the Pb speciation and the TCLP leaching contents from the contaminated soils before and after remediation were examined. Experimental results showed that： （1） After treatment with the combination agents （C＋B, B＋H or H＋C）, the concentration of the available Pb fractions in the soil was significantly reduced;while those of organic fraction bound Pb （OFB-Pb） and residual fraction of Pb （RF-Pb） were increased. The immobilization performance of Pb after 40 days was better than that after 25 days. After remediation, most of the available Pb fractions in the soil were transformed to the OFB-Pb. For example, after treatment with 20%B＋20%H and 10%H＋6%C, the concentration of the available Pb fractions was reduced from 331.3 mg·kg-1 to 91.8 mg·kg-1 and 96.57 mg·kg-1, while that of OFB-Pb was increased from 57.19 mg·kg-1 to 264.28 mg·kg-1 and 267.99 mg·kg-1, respectively. （2） The increased B ratio led to the worse immobilization performance of Pb for C＋B agents, the increased H ratio led to the better immobilization performance of Pb for B＋H agents, and the increased C ratio led to the better immobilization performance of Pb for H＋C agents. （3） The TCLP leaching concentration of Pb from the remediated soil was significantly reduced compared with the original contaminated soil, which would extenuate the pollution to the environment.
出处
《生态环境学报》
CSCD
北大核心
2013年第9期1608-1613,共6页
Ecology and Environmental Sciences
基金
国家自然基金资助项目(21077002
20877002)
北京市共建项目专项资助
关键词
土壤
铅污染
稳定化
修复
soil
Pb contamination
immobilization
remediation
