摘要:
石煤中含有较高含量的天然放射性核素，它的开发与利用会对环境造成放射性污染以及伴生的重金属污染等，近年来石煤的开发与利用对环境产生的放射性污染以及重金属污染等问题越发受到公众关注，江西作为全国石煤储量最为丰富的省份之一，石煤矿山大多为露天开采，废弃矿山长期受雨水淋溶、地表径流等对周边土壤环境造成了严重损害，为了对石煤矿区周边放射性及重金属复合污染土壤进行修复技术研究，采用振荡淋洗方法进行室内小试试验，根据江西省某石煤矿区现场采集的土壤检测结果显示，主要污染物指标为放射性核素铀以及重金属锌和镉；依据前人研究，针对其特有的放射性及重金属复合污染特征，选用盐酸、柠檬酸、草酸、EDTA、三氯化铁为淋洗剂，通过控制淋洗浓度、混合淋洗等因素来确定较优的淋洗条件。结果表明：各淋洗剂对复合污染土壤的去污效果综合最佳是草酸、盐酸以及三氯化铁；而不同浓度梯度下淋洗率最好的分别是1 mol/L的草酸和1 mol/L的盐酸溶液，组合淋洗剂对比单一淋洗剂的淋洗效果均有一定程度的提升，1 mol/L的草酸溶液与1 mol/L的盐酸溶液组合的淋洗剂对U、Cd、Zn的淋洗率均达到最高，分别是99.2%、97.8%和43.7%。该研究成果可用于现场淋洗修复复合污染土壤的小试，同时仍需考虑淋洗修复后土壤的潜在环境风险问题。
Abstract:
Stone coal contains a relatively high content of natural radionuclides. Its development and utilization will cause radioactive pollution and associated heavy metal pollution to the environment. In recent years, the development and utilization of stone coal has caused radioactive pollution and heavy metal pollution to the environment. More and more public attention has been paid to Jiangxi. As one of the provinces with the most abundant stone coal reserves in the country, most stone coal mines are open-pit mining. The long-term rainwater leaching and surface runoff of abandoned mines have caused serious damage to the surrounding soil environment. In order to study the remediation technology of the radioactive and heavy metal compound contaminated soil around the stone coal mine area, the vibration leaching method was used to conduct the indoor test. According to the soil test results collected on site in a stone coal mine area in Jiangxi Province, the main pollutant indexes were radionuclide uranium and heavy metal zinc and cadmium. According to previous studies, in view of its unique radioactive and heavy metal compound pollution characteristics,hydrochloric acid, citric acid, oxalic acid, EDTA and ferric trichloride were selected as eluents, and the better leaching conditions were determined by controlling leaching concentration and mixed leaching. The results show that in eluents the best comprehensive decontamination effects on compound polluted soil were oxalic acid, hydrochloric acid and ferric trichloride. The best leaching rates under different concentration gradients were 1 mol/L oxalic acid and 1 mol/L hydrochloric acid solution, and the elution effect of combined eluent was improved to some extent compared with a single eluent. The leaching rate of U, Cd and Zn with the mixture of 1 mol/L oxalic acid solution and 1 mol/L hydrochloric acid solution was the highest achieved 99.2%, 97.8% and 43.7%. The research results can be used for the small-scale trial of on-site leaching of remediation of compound contaminated soil, and the potential environmental risks of the soil after leaching and remediation still need to be considered.
百度学术
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