摘要
为探究碳酸钙对污染土壤中Pb、Zn、Cd的稳定化作用,以甘肃省白银东大沟Pb、Zn、Cd等重金属复合污染土壤为研究对象,通过添加不同质量的碳酸钙进行稳定化实验。结果表明,在轻度污染土壤中,当CaCO3的添加量由1%增加至15%时,pH值由初始7.45升高至7.91,浸出浓度降低;用水平振荡法浸出时,Pb、Zn的稳定效率可分别达48.93%、51.18%;用硫酸硝酸法浸出时,Pb、Zn的稳定效率可分别达50.48%、21.40%。在重度污染土壤中,当CaCO3的添加量由2%增加至18%时,pH值由初始6.76升高至7.16,浸出浓度降低;用水平振荡法浸出时,Pb、Zn、Cd的稳定效率可分别达48.07%、74.21%、99.19%;用硫酸硝酸法浸出时,Pb、Zn、Cd的稳定效率可分别达42.32%、65.55%、78.39%。添加碳酸钙后土壤pH值略有升高,这是由于CaCO3在土壤溶液中溶解产生OH-,土壤中的重金属形成了氢氧化物和碳酸盐沉淀,有效降低了重金属的迁移性,起到重金属稳定化作用。
In order to explore the stabilization effects of calcium carbonate on Pb, Zn and Cd in contaminated soil, the heavy metal (such as Pb, Zn, and Cd) compound contaminated soils in Baiyin Dongdagou of Gansu province were studied, and by adding different amounts of calcium carbonate, the stabilization experiments were conducted. The results showed that in the slightly polluted soil, when the addition amount of CaCO 3 increased from 1% to 15%, the pH value increased from the initial 7.45 to 7.91, and the leaching concentration decreased gradually.and the stabilization efficiency of Pb, Zn reached 48.93%,51.18% respectively with horizontal vibration method and 50.48%、21.40% respectively with sulphuric acid & nitric acid method. In heavily polluted soil, when the addition amount of calcium carbonate increased from 2% to 18%, the pH increased from the initial 6.76 to 7.16, and the leaching concentration decreased gradually. The stabilization efficiency of Pb, Zn and Cd reached 48.07%,74.21%,99.19% respectively with horizontal vibration method and 42.32%,65.55%,78.39% respectively with sulphuric acid & nitric acid method. The pH value of the soil increased slightly after adding calcium carbonate. This is because CaCO 3 dissolved in the soil solution to produce OH -. The heavy metals in the soil formed hydroxide and carbonate precipitation, which effectively reduced the migration of heavy metals and stabilized the heavy metals.
作者
张湘茗
任学昌
万建新
王建钊
郭梅
王震
蒙晓瑞
包丽婷
ZHANG Xiangming;REN Xuechang;WAN Jianxin;WANG Jianzhao;GUO Mei;WANG Zhen;MENG Xiaorui;BAO Liting(School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China)
出处
《有色金属工程》
CAS
北大核心
2019年第6期114-120,共7页
Nonferrous Metals Engineering
基金
国家自然科学基金资助项目(51268026)~~
关键词
碳酸钙
重金属
污染土壤
稳定化
calcium carbonate
heavy metal
contaminated soil
stabilization
