李尤,廖晓勇,阎秀兰,龚雪刚.鼠李糖脂淋洗修复重金属污染土壤的工艺条件优化研究[J].农业环境科学学报,2015,34(7):1287-1292. |
鼠李糖脂淋洗修复重金属污染土壤的工艺条件优化研究 |
Optimization of Technological Conditions for Remediation of Heavy Metal Contaminated Soil by Rhamnolipid Washing |
投稿时间:2015-03-01 |
DOI:10.11654/jaes.2015.07.009 |
中文关键词: 土壤 重金属 鼠李糖脂 淋洗修复 形态 工艺条件 |
英文关键词: soil heavy metals rhamnolipid soil washing speciation technological conditions |
基金项目:国家高技术研究发展(863)计划(2012AA06A201);北京市科技计划课题(Z141100000914011) |
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中文摘要: |
以湖南某冶炼厂周边重金属-砷复合污染土壤为对象,应用表面活性剂鼠李糖脂为主要淋洗剂,研究了不同pH值、温度和淋洗次数等工艺条件对重金属及砷淋洗效果的影响。结果表明:Zn、Cd、As在淋洗剂pH为2时提取能力最高,分别可达397、30、21 mg·kg-1,但Cu的洗脱能力随着pH值的升高而增加;淋洗剂对Cd、Zn、Cu、As的洗脱能力在40 ℃时达到最大值,在30 ℃时淋洗液中Pb浓度最高,为54 mg·kg-1;多次淋洗有助于土壤中重金属及砷的洗脱,Pb、Cd、Zn、Cu、As的3次淋洗效率分别可达23.1%、53.8%、44.7%、63.2%和34.4%;淋洗后土壤中重金属的酸可提取态、氧化物结合态及有机物结合态浓度大幅降低,砷的残渣态和氧化物结合态浓度明显下降。试验研究确定的最优淋洗条件为污染土壤淋洗修复工程应用提供了可借鉴的工艺参数。 |
英文摘要: |
Rhamnolipid biosurfactant has showed to be effective in removing heavy metals from soils. Here a study was initiated to optimize pH, temperature and washing time for removal of heavy metals and arsenic by rhamnolipid from contaminated soil collected from a smeltery in Hunan. At solution pH 2, the extraction of Zn, Cd, and As was the greatest, which was 397, 30, and 21 mg·kg-1, respectively. However, the washing rates of Cu increased with increasing pH values. At the temperature of 40 ℃, the maximum elution for Cd, Zn, Cu, and As was obtained, which was 36, 438, 33, and 29 mg·kg-1, respectively, whereas the highest leaching concentration of Pb(54 mg·kg-1) was obtained at 30 ℃. Three successive washing cycles with the mixture solutions of rahmnolipid and HCl were shown to remove 23.10% of Pb, 53.78% of Cd, 44.74% of Zn, 63.19% of Cu, and 34.37% of As. Successive washing resulted in significant declines in acid extractable, oxides bound and organic bound heavy metals, while in residual and oxides bound arsenic. The present results could provide a technical guidance for remediation of heavy metal contaminated soils by rhamnolipid washing. |
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