Cho Kanghee, Kang Jinkyu, Kim Songbae, Purev Oyunbileg, Myung Eunji, Kim Hyunsoo, Choi Nagchoul
Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea.
Department of Energy and Resource Engineering, Chosun University, Gwangju, 61452, Korea.
Environ Sci Pollut Res Int. 2021 Sep;28(35):48184-48193. doi: 10.1007/s11356-021-14024-z. Epub 2021 Apr 26.
Thermal treatment of mercury (Hg)-contaminated soil was studied to investigate the desorption behavior of Hg at different temperatures. The soil samples were collected from two locations with different land uses around the mine and industrial site. The effect of soil properties such as inorganic carbonate minerals and organic matter content on Hg desorption was investigated to understand the thermal desorption process. The effect of soil composition on Hg desorption showed that behavior at 100 °C was similar, but a different behavior could be found at 300 °C. The thermal desorption efficiency at 300 °C is affected by the thermal properties of soils and the Hg desorption capacity of the soils. The Hg from both soil types was removed above 300 °C, and Hg was effectively removed from mine soil due to the partial decomposition of carbonate in the soil composition, while industrial soil showed that desorption would be restrained by Hg organic matter complexes due to organic matter content. Despite a relatively higher concentration of Hg in the mine soil, Hg removal efficiency was greater than that in the industrial soil. Sequential extraction results showed that only the Hg fractions (residual fractions, step 6) in mine soil changed, while the industrial soil was affected by changes in Hg fractions (step 3 to step 6) at 300 °C. Changes in soil pH during thermal desorption are also influenced by heating time and temperature. Therefore, the mechanisms of Hg desorption during thermal treatment were observed by soil properties. The volatilization of Hg in the soil is induced by organic carbon, while soil Hg release is controlled by organic matter complexes.
研究了汞（Hg）污染土壤的热处理过程，以探究不同温度下汞的解吸行为。土壤样品采集自矿区和工业场地周边两块不同土地利用类型的区域。研究了无机碳酸盐矿物和有机质含量等土壤性质对汞解吸的影响，以了解热解吸过程。土壤组成对汞解吸的影响表明，100℃时的行为相似，但在300℃时会发现不同的行为。300℃时的热解吸效率受土壤热性质和土壤汞解吸能力的影响。两种土壤类型中的汞在300℃以上均被去除，由于土壤组成中碳酸盐的部分分解，矿区土壤中的汞被有效去除，而工业土壤由于有机质含量，汞解吸会受到汞-有机质络合物的抑制。尽管矿区土壤中汞的浓度相对较高，但其去除效率高于工业土壤。连续提取结果表明，仅矿区土壤中的汞组分（残留组分，步骤6）发生了变化，而工业土壤在300℃时受汞组分（步骤3至步骤6）变化的影响。热解吸过程中土壤pH值的变化也受加热时间和温度的影响。因此，通过土壤性质观察了热处理过程中汞解吸的机制。土壤中汞的挥发由有机碳诱导，而土壤汞的释放受有机质络合物控制。
