College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China.
Research and Design Institute of Environmental Science of Guizhou Province, Guiyang, 550023, China.
Environ Sci Pollut Res Int. 2018 Aug;25(24):24135-24142. doi: 10.1007/s11356-018-2387-2. Epub 2018 Jun 12.
In this study, low-thermal technology was used to treat the mercury contaminated farmland soil from a chemical plant in Guizhou Province, China. A series of field planting experiments were also aimed at determining the content of total and methyl-Hg in crop plants after thermal treatment. The results showed that the mercury concentration in soils was reduced about 70% from 255.74 mg/kg to 80.63 mg/kg when treated at 350 °C for 30 min in engineering-scale experiments, and the treated soil retained most of its original soil. Organic-bound and residual mercury in treated soil were reduced by 64.1 and 56.4% by means of a sequential extraction procedure, respectively. The total and methyl-mercury concentrations in crops decreased significantly, and the degree of soil mercury accumulation to crop roots has been reduced significantly. The total Hg concentrations in potato and corn were lower than the mercury tolerance limits for food in China, and the Hg concentration of radish was close to the limit. The technology provides a more sustainable remediation method for treating mercury-contaminated farmland soil in future engineering applications.
本研究采用低温热脱附技术对来自中国贵州省某化工厂的汞污染农田土壤进行处理，并进行了一系列田间种植实验，旨在确定热脱附处理后作物中总汞和甲基汞的含量。结果表明，在工程规模实验中，土壤在 350°C 下处理 30 分钟后，汞浓度从 255.74mg/kg 降低到 80.63mg/kg，约降低了 70%，且处理后的土壤保留了大部分原有土壤。采用连续提取程序，有机结合态和残渣态汞在处理土壤中的含量分别降低了 64.1%和 56.4%。作物中的总汞和甲基汞浓度显著降低，土壤中汞向作物根系的积累程度显著降低。土豆和玉米中的总汞浓度低于中国食品中汞的耐受限量，萝卜中的汞浓度接近限量。该技术为未来工程应用中处理汞污染农田土壤提供了一种更可持续的修复方法。
