Jun Jiang Ren-kou Xu Tian-yu Jiang Zhuo Li. Immobilization of Cu(II) Pb(II) and Cd(II) by the addition of rice straw derived biochar to a simulated polluted Ultisol. Journal of Hazardous Materials 2012 229– 230 :145– 150. http://dx.doi.org-10.1016-j.jhazmat.2012.05.086

 

Abstract: To develop new remediation methods for acidic soils polluted by heavy metals the chemical fractions of Cu(II) Pb(II) and Cd(II) in an Ultisol with and without rice straw biochar were compared and the effect of biochar incorporation on the mobility and bioavailability of these metals was investigated. In light of the decreasing zeta potential and increasing CEC the incorporation of biochar made the negative soil surface charge more negative. Additionally the soil pH increased markedly after the addition of biochar. These changes in soil properties were advantageous for heavy metal immobilization in the bulk soil. The acid soluble Cu(II) and Pb(II) decreased by 19.7–100.0% and 18.8–77.0% respectively as the amount of biochar added increased. The descending range of acid soluble Cd(II) was 5.6–14.1% which was much lower than that of Cu(II) and Pb(II). When 5.0 mmol-kg of these heavy metals was added the reducible Pb(II) for treatments containing 3% and 5% biochar was 2.0 and 3.0 times higher than that of samples without biochar while the reducible Cu(II) increased by 61.6% and 132.6% for the corresponding treatments respectively. When 3% and 5% biochar was added the oxidizable portion of Pb(II) increased by 1.18 and 1.94 times respectively while the oxidizable portion of Cu(II) increased by 8.13 and 7.16 times respectively primarily due to the high adsorption affinity of functional groups of biochar to Cu(II). The residual heavy metal contents were low and changed little with the incorporation of biochar.

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稻草生物质炭对模拟污染红壤中Cu(II)、Pb(II)和Cd(II)的钝化作用

姜军，徐仁扣，蒋田雨，李卓

Journal of Hazardous Materials 229– 230 (2012) 145– 150

http://dx.doi.org-10.1016-j.jhazmat.2012.05.086

    摘要：本文研究了稻草生物质炭对模拟重金属污染红壤中Cu(II)、Pb(II)和Cd(II)形态分布的影响，评价了生物质炭对红壤中重金属的钝化作用。结果表明，添加生物质炭使土壤胶体动电电位向负值方向位移，且土壤的阳离子交换量(CEC)增加，说明土壤表面负电荷增多。添加生物质炭也使土壤pH显著提高。这些变化均有利于红壤中重金属的钝化。研究表明，添加生物质炭后，土壤酸溶性Cu(II)和酸溶性Pb(II)含量的降幅分别在19.7-100%和18.8-77.0%之间。随着生物质炭添加量的增加，重金属的钝化作用增强。但添加生物质炭仅使红壤酸溶性Cd(II)下降5.6-14.1%，明显小于其对Cu(II)和Pb(II)的钝化作用。当外源重金属浓度为5.0 mmol-kg时，添加3%和5%生物质炭使红壤还原态Pb(II)浓度比对照高2.0和3.0倍，氧化态Pb(II)增加了1.18和1.94倍，而氧化态Cu(II)增加了8.13和7.16倍。氧化态Cu(II)含量的变化幅度明显高于氧化态Pb(II)，原因在于生物质炭表面有机官能团对Cu(II)的亲和能力更高。添加生物质炭对土壤残渣态重金属含量的影响不大。