水体镉铅铜复合污染对玉蕊生长及元素吸收的影响

Effect of combined pollution of Cd,Pb and Cu on growth and element absorption of Barringtonia racemosa

【目的】探究水体Cd-Pb-Cu重金属复合污染对玉蕊Barringtonia racemosa生长和元素吸收的影响,为玉蕊在重金属复合污染湿地修复方面的应用提供理论依据。【方法】以玉蕊为材料,采取室内盆栽试验模拟湿地环境,研究Cd-Pb-Cu复合污染对玉蕊生长、养分吸收和重金属吸收分配的影响。【结果】玉蕊株高在20 mg·L^(−1)Cd+200 mg·L^(−1)Pb+400 mg·L^(−1)Cu污染水平下受到显著抑制,与CK(无污染)相比减少14.20%,各处理地径生长均未受显著影响;在5 mg·L^(−1)Cd+100 mg·L^(−1)Cu+50 mg·L^(−1)Pb污染水平下玉蕊的总生物量较CK显著增加;玉蕊在各处理下氮磷钾养分含量均与CK无显著差异,但全株各养分元素累积量均显著高于CK;Cd-Pb-Cu复合污染增加了玉蕊全株Cd、Pb、Cu含量和累积量,各部位Cd、Pb、Cu含量和累积量均随污染浓度升高呈先升后降趋势;相关性分析表明,复合污染下K和Cu对玉蕊的株高、环境适应能力的影响比其他元素更明显;综合转移系数和聚类分析表明,玉蕊在10 mg·L^(−1)Cd+100 mg·L^(−1)Pb+200 mg·L^(−1)Cu污染水平下具有更强的重金属富集能力和转移能力。【结论】玉蕊对Cd-Pb-Cu复合污染水体具有较强的适应性和修复潜能,在Cd、Pb、Cu污染湿地的生态修复中有较好应用前景。

【Objective】To explore the effects of Cd-Pb-Cu combined heavy metal pollution on the growth and element absorption of Barringtonia racemosa,and provide a theoretical basis for the application of B.racemosa in the remediation of heavy metal combined pollution wetland.【Method】The effects of Cd-Pb-Cu compound pollution on the growth,nutrient uptake,and heavy metal uptake and distribution of B.racemosa were investigated by an indoor pot experiment which simulated wetland environment.【Result】The plant height was significantly inhibited under 20 mg·L^(−1) Cd+200 mg·L^(−1) Pb+400 mg·L^(−1) Cu,decreasing by 14.20%compared with CK(no pollution),while the growth of ground diameter was not affected under all pollution treatments.Comparing with CK,the total biomass of B.racemosa increased significantly under 5 mg·L^(−1) Cd+100 mg·L^(−1) Cu+50 mg·L^(−1) Pb.The contents of N,P and K were not significantly different from CK under all pollution treatments,however,the accumulation of all three nutrient elements in whole plant were significantly higher than that of CK.The contents and accumulations of Cd,Pb,Cu in whole plant were improved under Cd-Pb-Cu compound pollution conditions.With the increase of pollution concentration,the contents and accumulations of Cd,Pb,Cu all showed a trend of increasing first and then decreasing.The correlation analysis showed that K and Cu had more pronounced effects on plant growth and environmental adaptability of B.racemosa than other elements.The integrated transfer coefficient and cluster analysis showed that B.racemosa demonstrated stronger enrichment and transfer ability for heavy metals under 10 mg·L^(−1) Cd+100 mg·L^(−1) Pb+200 mg·L^(−1) Cu.【Conclusion】B.racemosa has strong adaptability and restoration ability to Cd-Pb-Cu compound pollution water,which can be used for ecological restoration of Cd,Pb,Cu polluted wetlands.