改性磷石膏对镉铅污染土壤修复改良效果研究

    Remediation of Cadmium- and Lead-contaminated Soil by Using Modified Phosphogypsum

    • 摘要: 为探索改性磷石膏对镉铅污染土壤修复改良的效果, 实现农产品安全生产, 采用田间试验, 共设CK(不施加改性磷石膏)、T1(改性磷石膏施用量为3 000 kg·hm-2)和T2(改性磷石膏施用量为6 000 kg·hm-2)3个处理, 研究改性磷石膏对镉铅污染土壤修复改良效果。结果表明, 与原始磷石膏相比, 改性磷石膏表面纹理更加粗糙, 结构也更加松散, 表面附着更多生物炭颗粒。与T1处理相比, T2处理更能显著提升土壤pH值、EC值、有机质和速效养分含量, 显著降低土壤有效态镉铅和玉米籽粒镉铅含量。另外, T2处理对提高玉米单产、百粒重、粗蛋白含量、钙含量、磷含量和叶绿素含量效果也最显著, 较CK分别显著提高33.73%、21.43%、20.21%、52.63%、19.35%和24.66%。相关性分析结果表明, 青贮玉米产量与土壤pH, EC, 有机质、碱解氮、速效磷和速效钾含量呈显著正相关, 与土壤有效态镉铅含量呈显著负相关。综上所述, 改性磷石膏施用量为6 000 kg·hm-2时更能有效修复改良镉铅复合污染土壤, 提升土壤肥力, 阻控农产品中镉铅吸收转移。研究结果可为镉铅污染土壤的农产品安全生产提供理论依据, 促进资源与环境的循环利用。

       

      Abstract: The effect of modified phosphogypsum on the remediation of cadmium (Cd)- and lead (Pb)-contaminated soil was explored to realize the safe production of agricultural crops. A field experiment was conducted with three treatments: control (without modified phosphogypsum), T1 (with modified phosphogypsum applied at 3 000 kg·hm-2) and T2 (with modified phosphogypsum applied at 6 000 kg·hm-2). Compared with the original phosphogypsum, the modified phosphogypsum had a rougher surface texture, looser structure, and more biochar particles attached to the surface. The T2 treatment greatly increased the pH, EC, organic matter content, and soil available nutrient content and greatly reduced the soil effective states of Cd/Pb, and maize kernel Cd/Pb contents compared with the T1 treatment. Additionally, T2 treatment gave the largest increases in the maize yield per, 100-kernel weight, crude protein percentage, calcium percentage, phosphorus percentage, and chlorophyll content, by 33.73%, 21.43%, 20.21%, 52.63%, 19.35%, and 24.66%, respectively, compared with the control group. Correlation analysis show that the maize silage yield was significantly positively correlated with the soil pH, EC, organic matter, alkali-hydrolyzed nitrogen, available phosphorus, and available potassium content. It was also significantly and negatively correlated with the soil effective states of Cd/Pb. In summary, the application of modified phosphogypsum at a dose of 6 000 kg·hm-2 can effectively remediate and improve Cd/Pb-contaminated soil to enhance soil fertility and reduce Cd/Pb uptake by crops. The results of this study provide a theoretical basis for the safe production of agricultural crops in Cd/Pb-contaminated soil, promote recycling of resources, and reduce environmental pollution.

       

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