Screening biochars for heavy metal retention in soil: role of oxygen functional groups.
Screening biochars for heavy metal retention in soil: role of oxygen functional groups.
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DOI：
10.1016/j.jhazmat.2011.03.063
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发表时间：
2011-06
影响因子：
13.6
通讯作者：
Minori Uchimiya;Sechin Chang;K. T. Klasson
中科院分区：
文献类型：
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作者：
Minori Uchimiya;Sechin Chang;K. T. Klasson
土壤有机和矿物组分的含氧羧基、羟基和酚类表面官能团在结合金属离子中起着核心作用，生物炭改良剂可以提供增加土壤中这些表面配体的手段。在这项研究中，正矩阵因子分解（PMF）指纹的主要成分负责的重金属（铜，镍，镉，铅）的稳定和选定的元素（钠，钙，钾，镁，硫，铝，磷，锌）的释放和pH值的变化，生物炭修正土壤。PMF分析表明，有效的重金属稳定化发生的同时，释放的Na，Ca，S，K，和Mg来自土壤和生物炭，导致多达一个数量级或更大的平衡浓度相对于土壤的控制。在风化酸性土壤中，生物炭对重金属（特别是Pb和Cu）的稳定能力与其O/C比、pHpzc、总酸度和1H NMR分析所揭示的含氧官能团数量直接相关。平衡形态计算表明水解对总可溶性金属浓度的影响较小，进一步表明生物炭的表面配体结合的重要性，这可能是由生物炭诱导的pH值增加促进。
Oxygen-containing carboxyl, hydroxyl, and phenolic surface functional groups of soil organic and mineral components play central roles in binding metal ions, and biochar amendment can provide means of increasing these surface ligands in soil. In this study, positive matrix factorization (PMF) was first employed to fingerprint the principal components responsible for the stabilization of heavy metals (Cu, Ni, Cd, Pb) and the release of selected elements (Na, Ca, K, Mg, S, Al, P, Zn) and the pH change in biochar amended soils. The PMF analysis indicated that effective heavy metal stabilization occurred concurrently with the release of Na, Ca, S, K, and Mg originating from soil and biochar, resulting in as much as an order or magnitude greater equilibrium concentrations relative to the soil-only control. In weathered acidic soil, the heavy metal (especially Pb and Cu) stabilization ability of biochar directly correlated with the amount of oxygen functional groups revealed by the O/C ratio, pHpzc, total acidity, and by the1H NMR analysis. Equilibrium speciation calculation showed minor influence of hydrolysis on the total soluble metal concentration, further suggesting the importance of binding by surface ligands of biochar that is likely to be promoted by biochar-induced pH increase.