Leaching of rare earth elements from contaminated soils using saponin and rhamnolipid bio-surfactant
来源期刊：Journal of Rare Earths2017年第9期
论文作者：周丹 李真真 罗仙平 苏佳
文章页码：911 - 919
摘 要：The effective leaching of rare earth elements（La, Ce, Y and Eu） from simulated contaminated soil using bio-surfactant was investigated in a lab-scale column leaching experiment, where anionic biosurfactant rhamnolipid and non-ionic biosurfactant saponin were used as washing solutions. Soil properties and the rare earth element fractions were analysed to define the effect of leaching on soil and elemental speciation. Column leaching results showed that saponin solution was more effective than rhamnolipid in the removal of the four rare earth elements tested, with the accumulative removal efficiency of La, Ce, Y and Eu following flushing with 400 mL of 25 g/L saponin, reaching 35.258%, 26.072%, 31.476% and 30.849%, respectively. The change in REE speciation showed that REE removed from soils were mainly derived from the acid-soluble and residual fractions released when rhamnolipid solution was used as a leaching agent. However, for saponin leaching, removed REE amounts were derived from acid-soluble and reducible fractions. Complexation interactions were identified between saponin and REEs, according to infrared spectroscopy and ion exchange data, with saponin complexing with La, Ce, Y, and Eu at a complex ratio of 1:1.
周丹1，李真真1，罗仙平1,2，苏佳1
1. Jiangxi Key Laboratory of Mining & Metallurgy Environmental Pollution Control, Jiangxi University of Science and Technology2. Key Laboratory of Ionic-type Rare Earth Resources Development and Application, Ministry of Education
摘 要：The effective leaching of rare earth elements（La, Ce, Y and Eu） from simulated contaminated soil using bio-surfactant was investigated in a lab-scale column leaching experiment, where anionic biosurfactant rhamnolipid and non-ionic biosurfactant saponin were used as washing solutions. Soil properties and the rare earth element fractions were analysed to define the effect of leaching on soil and elemental speciation. Column leaching results showed that saponin solution was more effective than rhamnolipid in the removal of the four rare earth elements tested, with the accumulative removal efficiency of La, Ce, Y and Eu following flushing with 400 mL of 25 g/L saponin, reaching 35.258%, 26.072%, 31.476% and 30.849%, respectively. The change in REE speciation showed that REE removed from soils were mainly derived from the acid-soluble and residual fractions released when rhamnolipid solution was used as a leaching agent. However, for saponin leaching, removed REE amounts were derived from acid-soluble and reducible fractions. Complexation interactions were identified between saponin and REEs, according to infrared spectroscopy and ion exchange data, with saponin complexing with La, Ce, Y, and Eu at a complex ratio of 1:1.
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