| 铈锰改性生物炭对土壤As的固定效应 |
| 摘要点击 2064 全文点击 617 投稿时间：2019-03-29 修订日期：2019-05-25 |
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| 中文关键词 改性生物炭 砷(As) pH值 溶解有机质(DOM) 酶活性 |
| 英文关键词 modified biochar arsenic(As) pH value dissolved organic matter (DOM) enzyme activity |
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| 中文摘要 |
| 利用高温热解法在600℃下制备铈锰改性生物炭（modified biochar，MBC），以3种基本性质差异较大的砷（As）污染红壤、黄壤和紫色土为研究对象，探讨了MBC的施用对土壤活性As的影响及固定效应.结果表明：改性生物炭（MBC）的施用导致3种土壤中水溶态As含量显著降低，随着施用量的增加，MBC对As的固定效率不断升高，当添加量为1%~10%时，MBC对3种土壤中活性As的固定效率为：红壤70.59%~94.72%，黄壤75.24%~98.35%，紫色土为76.53%~99.61%，在MBC添加量为10%时，其对3种土壤中有效As的固定效率均达到了95%以上，而未改性生物炭的施用则导致土壤As的活化效应明显.比较而言，MBC对3种土壤中有效As的固定效率大小排序为：紫色土 > 黄壤 > 红壤，MBC的施用导致了土壤中活性态As向稳定态转化，发生了由非专性吸附（F1）、专性吸附态（F2）向结晶水合铁铝氧化物结合态（F4）和残渣态（F5） As的转化过程，使得土壤中As的迁移性能降低，根据扫描电镜（SEM）及X射线衍射分析（XRD）的结果，MBC对As的固定作用与生物炭上铈锰氧化物的成功负载有关.因此，MBC对As污染土壤表现出良好的应用修复潜力. |
| 英文摘要 |
| Loaded cerium and manganese modified biochar (MBC) was prepared by high temperature pyrolysis at 600℃, and three kinds of arsenic (As) contaminated soils were selected for remediation, including red soil, yellow soil, and purple soil with different basic properties. During the soil incubation experiment, the goal of this research was to investigate the influence of MBC as a stabilizer of the mobility of arsenic in these three soils after treated by biochar (BC) and MBC. The results revealed that the application of MBC resulted in a significant decrease of water soluble arsenic content in the three different kinds of soils. With the additional amount increasing, the stabilization efficiency of soil arsenic increased continuously. When the applied amount of MBC ranged from 1% to 10%, the stabilization efficiency of arsenic was in the range of 70%-99%. The corresponding stabilizing efficiencies of the red, yellow, and purple soils were 70.59%-94.72%, 75.24%-98.35%, and 76.53%-99.61%, respectively, after being treated by MBC at 1%-10%. At a higher addition of 10% MBC, the efficiency of stabilization reached 95%. On the contrary, the addition of unmodified biochar caused the activation and dissipation of As in soils. Comparatively speaking, according to the stabilization efficiency, the three soils ranked in this decreasing order:purple soil > yellow soil > red soil. It also illustrated that the addition of MBC into soils led to the conversion of active arsenic to stable ones in soil, indicating the conversion from non-specifically sorbed (F1) and specifically sorbed (F2) to well-crystallized hydrous oxides of Fe and Al (F4) and residual phases (F5), which reduced the mobility of arsenic in these soils. According to the analysis of scanning electron microscopy (SEM) and X-ray diffraction analysis, the immobilization of arsenic by MBC was strongly related to the successful loading of cerium-manganese oxide onto biochar. Therefore, MBC can be used to make suitable amendments to immobilize As in soils for remediation of arsenic-contaminated farmland soils. |
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