应用纳米气泡气浮应急修复重金属污染土壤

Emergency Remediation of Heavy Metal Contaminated Soil by Nanobubbles Flotation

为了确定纳米气泡气浮快速修复重金属污染土壤的选别工艺,采用自制纳米气泡气浮装置为试验仪器,模拟含Cu^2+、Zn^2+、Pb^2+、Cd^2+、Ni^2+和Cr^3+等重金属离子溶液泄漏导致土壤重金属污染事件,考察了磨矿细度、pH值等参数对重金属脱除效率的影响。结果表明,当硫酸铵用量为30 kg/t、硫化钠用量为36 kg/t、丁基黄药用量为2500 g/t、2#油用量为1500 g/t、溶液pH值为8.0和浮选时间为60 min时,经过“1粗3扫”后,污染土壤中Cu^2+、Cd^2+、Ni^2+、Pb^2+、Zn^2+和Cr^3+的脱除率分别为90.08%、87.92%、85.95%、84.77%、78.85%和75.58%;获得泡沫产品中Cu^2+、Cd^2+、Ni^2+、Pb^2+、Zn^2+和Cr^3+含量分别为12.01×10^4 mg/kg、11.72×10^4 mg/kg、11.46×10^4 mg/kg、11.30×10^4 mg/kg、10.51×10^4 mg/kg、10.08×10^4 mg/kg,达到了硫化矿精矿质量要求,具有综合回收价值。研究获得的工艺流程对重金属污染土壤的应急修复具有指导意义。

A self-made nanobubble air flotation device was used as an experimental instrument to simulate the soil heavy metal pollution event caused by the leakage of solution containing Cu^2+,Zn^2+,Pb^2+,Cd^2+,Ni^2+ and Cr^3+,and the effects of parameters,such as grinding fineness and pH value on the removal efficiency of heavy metal ions were investigated to determine the rapid remediation process of heavy metal contaminated soil by nanobubbles flotation.The results of research showed that when the dosage of ammonium sulfate is 30 kg/t,the dosage of Na2S is 36 kg/t,the dosage of butyl xanthate is 2500 g/t,pH value is 8.0 and flotation time is 60 min,the removal rates of Cu^2+,Cd^2+,Ni^2+,Pb^2+,Zn^2+ and Cr^3+ in the contaminated soil were 90.08%,87.92%,85.95%,84.77%,78.85%and 75.58%,respectively after"one roughing and three scavenging".The contents of Cu^2+,Cd^2+,Ni^2+,Pb^2+,Zn^2+ and Cr^3+ in the foam products were 12.01×10^4 mg/kg,11.72×10^4 mg/kg,11.46×10^4 mg/kg,11.30×10^4 mg/kg,10.51×10^4 mg/kg,10.08×10^4 mg/kg,respectively,which reached the quality requirements of sulfide concentrate and had comprehensive recovery value.The technological process obtained from the study has guiding significance for the emergency remediation of heavy metal contaminated soil.