Cadmium, lead, and zinc immobilization in soil using rice husk biochar in the presence of citric acid
Cadmium, lead, and zinc immobilization in soil using rice husk biochar in the presence of citric acid
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DOI：
10.1007/s13762-021-03185-6
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发表时间：
2021-02
影响因子：
3.1
通讯作者：
M. Islam;R. Gao;J. Y. Gao;Z. Song;U. Ali;H. Hu
中科院分区：
文献类型：
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作者：
M. Islam;R. Gao;J. Y. Gao;Z. Song;U. Ali;H. Hu
在低分子量有机酸存在的情况下，生物炭与重金属之间的相互作用在很大程度上是未知的，但了解生物炭对重金属在根际固定化的影响是很重要的。在一项培养实验中，研究了不同量的生物炭（5%）和柠檬酸以及生物炭和柠檬酸的组合对镉、铅和锌在不同地球化学形态中的再分配的影响，包括它们在金属污染土壤中的生物利用度。与对照相比，添加生物炭、低浓度柠檬酸（2 mmol kg−1土壤）和低浓度柠檬酸的生物炭显著降低了酸溶性和有效（cacl2可萃取）镉、铅和锌的含量，其中生物炭加低浓度柠檬酸是最有效的处理方法。在高浓度柠檬酸（bbb5 - 20 mmol kg - 1土壤）和生物炭加高水平柠檬酸联合处理的情况下，这些趋势被逆转。随着培养时间的推移，生物炭与低浓度的柠檬酸结合，将最大量的酸溶性和可还原的镉、铅和锌转化为可氧化和残留的组分。结果表明，低浓度的柠檬酸增强了金属的固定化作用，而高浓度的柠檬酸则增强了金属的固定化作用。该研究的结论是，生物炭与如此低水平的柠檬酸实际上确实是最好的处理方法，并且可以作为金属在污染土壤中的固定/再分配的修正。图形抽象
The interaction between biochar and heavy metals in the presence of low molecular weight organic acids is largely unknown, but it is important to understand biochar’s influence on heavy metals immobilizing in the rhizosphere. The impacts of different amounts of biochar (5%) and citric acid, coupled with combinations of biochar and citric acid on the redistribution of cadmium, lead, and zinc among their different geochemical forms, including their bioavailability in metal contaminated soil, were investigated in an incubation experiment. Adding biochar, low concentration of citric acid (2 mmol kg−1soil), and biochar with a low level of citric acid markedly reduced the acid-soluble and available (CaCl2-extractable) cadmium, lead, and zinc compared to control in which biochar plus low concentration of citric acid proved to be the most effective treatment. These trends were reversed in the case of high concentrations of citric acid (> 5–20 mmol kg−1soil) and the combined biochar plus high levels of citric acid treatments. With incubation time, biochar in combination with a low concentration of citric acid transformed the largest amounts of acid-soluble and reducible cadmium, lead, and zinc into oxidizable and residual fractions. These results suggested that a low level of citric acid enhanced metals’ immobilization, while higher concentration of citric acid increased their mobilization. The study concluded that biochar with this low level of citric acid did in fact emerge as the best treatment, and can serve as an amendment for metals’ immobilization/redistribution in contaminated soils.Graphic abstract