GENG Lei1,2, QU Liya1,2,3, YU Zhi1,2, ZHANG Junfang2, GUO Chengcheng2,3
(1. College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China;
2. Research and Design Institute of Environmental Science of Guizhou Province, Guiyang 550023, China;
3. College of Geographic and Environmental Sciences, Guizhou Normal University, Guiyang 550025, China)
Abstract: The low-temperature pyrolysis technique, which can remove more than 90% of mercury from highly mercury contaminated soils, is one of the effective methods to remediate mercury contaminated soils. However, few research was focused on the removal of MeHg. In this study, contaminated soils were collected from areas of chemical plants and mines, the low-temperature pyrolysis technique was employed to remediate these contaminated soils, and soil properties, total mercury (THg), morphological distribution of mercury and MeHg in soils before and after remediation were investigated. The results showed that the residual form and the organic were the dominated mercury occurrences in heavily contaminated soils, and that, after remediation of the low-temperature pyrolysis, contents of MeHg and THg were reduced by 99.65% and 94.35% respectively in soils from the chemical plant area and reduced by 90.96% and 95.40% respectively in soils from the mining area, similarly, contents of organic bound and residual bound mercury were reduced by 96.62% and 93.08% respectively in soils from the chemical plant area and by 92.05% and 96.79% respectively in soils from the mining area. In addition, this study found that the paddy soil with high content of organic matter showed the strong ability of mercury methylation and the mean content of MeHg in paddy soils from the chemical plant area was 56.47±2.65 μg/kg, which is much higher than that (3.98±0.42 μg/kg) in paddy soils from the mining area.
Key words: low-temperature pyrolysis; soil; total mercury; morphological distribution; methylmercury
EARTH AND ENVIRONMENT Vol.47, No.5, Tot No.331, 2019, Page 689-695
