摘要
农业土壤重金属镉污染具有浓度低、面积大的特点,因此,原位钝化修复技术逐渐成为农业土壤镉污染治理的研究热点。针对目前农业土壤酸化及镉污染比较严重的状况,研究施加牡蛎壳粉对酸性土壤及镉形态转化的作用,以期达到对酸性镉污染土壤的修复。结果表明,添加5%、150目的牡蛎壳粉后,土壤pH值可由5.56提高至7.74;有效态镉含量由1.66 mg/kg降至0.801 mg/kg,钝化率达到51.7%。同时,交换态钙含量由0.998 g/kg升高至9.11 g/kg,可有效缓解酸性土壤钙流失的问题。对不同镉污染水平的土壤添加牡蛎壳粉后,镉的酸可溶态、可还原态和可氧化态分别降低了12.92%～20.97%、18.99%～31.10%和18.02%～47.80%,而残渣态则增加了124.2%～175.9%。因此,施加牡蛎壳粉可有效矫正土壤酸化的现象,并显著降低酸性土壤镉的生物活性,达到对镉钝化的效果。
The heavy metals contamination in agricultural soil has the characteristics of low concentration and large area. Therefore, in-situ immobilization technology becomes a hotspot for cadmium contaminated agricultural soils.Cultivation experiments were carried out to optimize the remediation of acid cadmium pollution soil by oyster shell powder. After adding 5%, 150 mesh of oyster shell powder and incubating with soil for 30 days, the soil pH increased from 5.56 to 7.74, and the content of active Cd decreased from 1.66 mg/kg to 0.801 mg/kg, by which the stabilization rate of active Cd in soil was up to 51.7%. In addition, the exchangeable calcium content rose from 0.998 g/kg to 9.11 g/kg after adding the oyster shell powder. The results also showed that the content Of Cd species, such as in the fractions of acid soluble, reducible and oxidable forms, were significantly reduced and might convert into those in the residual forms after adding soil with the oyster shell powder. It can be concluded that the addition of oyster shell powder can effectively remediate the acid Cd pollution soil.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2016年第1期178-182,共5页
Environmental Science & Technology
基金
福建省基金项目(2013J01162)
福建省科技重点项目(2012Y0052)
厦门科技计划项目(3502Z20143018)
集美大学创新团队基金资助项目(2010A007)
关键词
酸性土壤
牡蛎壳粉
镉污染
形态分布
acid soil
oyster shell powder
cadmium pollution
species distribution
