Metal availability in contaminated soils: I. Effects of flooding and organic matter on changes in Eh, pH and solubility of Cd, Ni andZn
Metal availability in contaminated soils: I. Effects of flooding and organic matter on changes in Eh, pH and solubility of Cd, Ni andZn
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DOI：
10.1023/a:1013762204510
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发表时间：
2001-01-01
影响因子：
3.1
通讯作者：
Singh, BR
中科院分区：
文献类型：
--
作者：
Kashem, MA;Singh, BR
土壤pH和Eh对降低水稻土重金属溶解度有重要作用。采用室内生长箱试验，研究了淹水和施用有机质对Cd、Ni、Zn污染土壤Eh、pH和溶解度的影响。进行了。Eh值随淹水时间的延长而降低。制革厂和明矾页岩污染土壤的Eh值变化更负，并在30天后稳定。城市污水污染土壤的Eh变化没有其它两种土壤大。土壤pH值随淹水时间的延长而增加。在65天的淹没，pH值增加约2，1和0.6单位的制革厂，城市污水和明矾页岩土壤，分别。在所有三种土壤中，有机质处理的土壤表现出较低的Eh和较高的pH值相比，未处理的土壤。土壤溶液中Cd、Ni、Zn含量随淹水时间延长而降低。城市污水处理土壤中Cd、Zn的溶出浓度和制革厂土壤中Ni的溶出浓度均高于矾页岩土壤。有机质处理的土壤中可溶性金属浓度较低。有机质处理土壤中金属溶解度降低与土壤Eh和pH值变化较大有关。相关系数计算还表明，金属溶解度降低Eh和土壤溶液中的pH值增加。
Soil pH and Eh play an important role in reducing heavy metal solubility in paddy soils. To assess the effects of flooding and organic matter application on changes in Eh, pH and solubility of Cd, Ni and Zn in contaminated soils, a growth chamber experiment with rice plants (Oryza sativa L.) was conducted. Eh values decreased with flooding time in all three soils. The changes of Eh values were more negative in the tannery and alum shale contaminated soils and stabilized after 30 days of submergence. The Eh changes were not so large in the city sewage contaminated soil as in the other two soils. Soil pH increased with flooding time. During the 65 days of submergence, pH increase was about 2, 1 and 0.6 units in the tannery, city sewage and alum shale soils, respectively. In all three soils, organic matter treated soil showed lower Eh and higher pH values compared to untreated soil. Concentration of Cd, Ni and Zn in soil solution decreased with flooding time. The solution concentration of Cd and Zn in the city sewage soil and of Ni in the tannery soil was higher than in the alum shale soil. The soluble metal concentration in all three soils was lower in organic matter treated soils. Reduced solubility of metals in the organic matter treated soils was related to larger changes of Eh and pH values in these soils. Correlation coefficient calculations also showed that metal solubility decreased with decreased Eh and increased pH in the soil solution.