Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou, 310058, China.
Chemosphere. 2023 Nov;340:139902. doi: 10.1016/j.chemosphere.2023.139902. Epub 2023 Aug 20.
The effects of different heavy metal pollution remediation methods on soil nutrient transformation and soil health remain unclear. In this study, the effects of phytoextraction (PE) and passivation remediation (PR) on Cd-polluted soil phosphorus transformation and availability were compared by pot experiment. The results showed that PE significantly reduced the concentrations of total and available Cd (both HO-Cd and DTPA-Cd) in soil, PR also decreased available Cd content but had no significant effect on total Cd content. PE slightly increased soil pH and NH-N content, while PR significantly increased soil pH, NO-N and AK content. PE promoted the conversion of stable P (including HCl-P and residual-P), and increased the content of labile P (including HO-P, NaHCO-P and NaHCO-P) and the proportion of moderately labile P (including NaOH-P and NaOH-P), while PR showed the opposite trend. PE showed a higher soil phoC gene abundance and acid phosphatase (ACP) activity, while PR showed a higher phoD gene copies and alkaline phosphatase (ALP) activity. Soil bacteria and phoD-harboring bacteria community was significantly affected by remediation methods and soil types. Compared with PR, PE reduced phoD-harboring bacterial diversity but significantly increased the abundance of genera associated with P dissolution (Streptomyces) and P conversion (Bradyrhizobium and Frankia), both of which were significantly positively correlated with labile P or moderately labile P. In general, compared with PR, PE can effectively remove soil Cd pollution, while maintaining a higher content of labile P and a higher proportion of moderately labile P, which can be considered as a green and sustainable remediation strategy conducive to soil quality.
不同重金属污染修复方法对土壤养分转化和土壤健康的影响尚不清楚。本研究通过盆栽试验比较了植物提取（PE）和钝化修复（PR）对 Cd 污染土壤磷转化和有效性的影响。结果表明，PE 显著降低了土壤中总 Cd 和有效 Cd（HO-Cd 和 DTPA-Cd）的浓度，PR 也降低了有效 Cd 的含量，但对总 Cd 含量没有显著影响。PE 略微增加了土壤 pH 和 NH4+-N 含量，而 PR 显著增加了土壤 pH、NO3--N 和 AK 含量。PE 促进了稳定 P（包括 HCl-P 和残渣-P）的转化，增加了易效 P（包括 HO-P、NaHCO3-P 和 NaHCO3-P）和中效 P（包括 NaOH-P 和 NaOH-P）的含量，而 PR 则呈现相反的趋势。PE 表现出较高的土壤 phoC 基因丰度和酸性磷酸酶（ACP）活性，而 PR 则表现出较高的 phoD 基因拷贝数和碱性磷酸酶（ALP）活性。修复方法和土壤类型对土壤细菌和 phoD 基因携带菌群落有显著影响。与 PR 相比，PE 降低了 phoD 基因携带菌的多样性，但显著增加了与 P 溶解（链霉菌）和 P 转化（慢生根瘤菌和弗兰克氏菌）相关的属的丰度，这些属与易效 P 或中效 P 呈显著正相关。总的来说，与 PR 相比，PE 能有效去除土壤 Cd 污染，同时保持较高的易效 P 含量和较高的中效 P 比例，可被视为一种有利于土壤质量的绿色可持续修复策略。
