| 生物炭负载氧化石墨烯对离子型稀土矿区土壤中重金属的阻控效应 |
| 摘要点击 2915 全文点击 1011 投稿时间：2021-05-18 修订日期：2021-08-13 |
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| 中文关键词 生物炭 氧化石墨烯 稀土矿区土壤 重金属形态 阻控效应 |
| 英文关键词 biochar graphene oxide soil of rare earth mining area form of heavy metals effect of controlling |
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| 中文摘要 |
| 以脐橙皮渣和天然石墨为原料，采用改进Hummer-共热解法制备了生物炭负载氧化石墨烯（BGO）材料，利用土壤钝化实验考察了BGO复合材料对稀土矿区土壤重金属形态的影响，土柱淋溶实验探讨了淋滤液重金属含量变化特征以及土壤重金属垂向迁移规律，确定了淋溶条件下重金属的累积释放模型.结果表明，添加BGO复合材料提高了土壤pH值和有机质含量，原矿和尾矿土壤酸可提取态Pb含量分别降低了17%和8.6%，原矿土壤中Mn形态含量变化不显著，而尾矿土壤酸可提取态、可还原态和可氧化态Mn含量都有所降低.土壤重金属累积释放特征可以分为两个阶段：快速释放阶段与缓慢释放阶段，添加BGO复合材料的土壤重金属释放速率要低于未添加的释放速率，尾矿土壤中Pb和Mn的释放量相比对照组分别减少了2.5%和28.4%，而原矿土壤分别减少了5.7%和1.1%.矿区土壤中重金属的释放是受多种扩散机制控制的复杂反应过程，BGO复合材料通过提高土壤pH值以及表面络合和沉淀等作用来有效阻控重金属的迁移. |
| 英文摘要 |
| Using navel orange peels and natural graphite as raw materials, biochar-supported graphene oxide (BGO) material was prepared using an improved hummer and co-pyrolysis method. The effects of BGO on the forms of heavy metals in the soil of a rare earth mining area were investigated via a soil passivation experiment. The soil column leaching experiment was carried out to explore the change characteristics of heavy metal content in leaching filtrate and the vertical migration law of heavy metals in soil, and the accumulation and release model of heavy metals under leaching conditions was determined. The results showed that pH value and organic matter content of soil with BGO composite increased, and acid-extractable Pb of raw ore and tailings soil decreased by 17% and 8.6%, respectively. The content of Mn form in the raw ore soil did not change significantly, whereas the content of acid-extractable, reducible, and oxidizable state in tailings soil decreased. The accumulation and release characteristics of heavy metals in soil could be divided into two stages:rapid release stage and slow stage. The release rate of heavy metals in soil with BGO composite was lower than that without addition, and the Pb and Mn removed from the tailings soil decreased by 2.5% and 28.4%, respectively, compared with that of the control group, whereas the raw ore soil decreased by 5.7% and 1.1%, respectively. The release of heavy metals in soil is a complex reaction process controlled by a variety of diffusion mechanisms. BGO composites can effectively inhibit the migration of heavy metals by increasing soil pH, surface complexation, and precipitation. |
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