水体镉铅铜复合污染对玉蕊生长及元素吸收的影响

[Objective]To explore the effects of Cd-Pb-Cu combined heavy metal pollution on the growth and element absorption of Barringtonia racemosa,and to provide 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 simulating wetland environment.[Results](1)The plant height was significantly inhibited at 20 mg·L-1Cd+200 mg·L-1Pb+400 mg·L-1Cu,decreasing by 12.44%compared with CK(no pollution),while the growth of ground diameter was not affected under all pollution treatments.(2)Comparing with CK.the total biomass of B.racemosa increased remarkably at 5 mg·L-1 Cd + 100 mg·L-1 Cu + 50 mg·L-1 Pb.(3)The content of N,P and K was not significantly different from CK under all pollution treatment,however,the accumulation of all three nutrient elements in whole plant was higher than that of CK significantly.(4)Besides,the content and accumulation of Cd,Pb,Cu in whole plant was improved under Cd-Pb-Cu compound pollution conditions.With the increase of pollution concentration,the content and accumulation of Cd,Pb,Cu all showed a trend of increasing first and then decreasing.(5)The correlation analysis showed that K and Cu had more pronounced effects on plant growth and environmental adaptability of B.racemosa than other elements.(6)The integrated transfer coefficient and cluster analysis showed that B.racemosa demonstrated stronger enrichment and transfer ability for heavy metals at 10 mg·L-1Cd+100 mg·L-1Pb+200 mg·L-1Cu.[Conclusion]B.racemosa has strong adaptability and restoration ability to Cd-Pb-Cu compound polluted water,which can be used for ecological restoration of Cd,Pb,Cu polluted wetlands.