镉-八氯代二苯并呋喃复合污染土壤中紫茉莉对镉的修复能力

Competence of Cd Phytoremediation in Cd-OCDF Co-contaminated Soil Using Mirabilis jalapa L.

针对土壤重金属-持久性有机物复合污染日益严重的现象,本研究以镉(Cd)和1,2,3,4,6,7,8,9-八氯代二苯并呋喃(OCDF)为典型的重金属和持久性有机污染物,选取紫茉莉为修复植物,通过温室盆栽实验研究Cd-OCDF复合污染土壤中植物的耐性以及有机物对植物提取土壤中Cd能力的影响.结果表明种植3个月期间,紫茉莉在Cd浓度≤200 mg·kg-1的复合污染土壤中具有较强的耐性,株高和生物量降低有限;与Cd单一污染相比,OCDF对紫茉莉株高、根部生物量无显著影响,Cd浓度200 mg·kg-1,OCDF浓度500μg·kg-1时,OCDF存在使紫茉莉地上生物量降低22.19%,其它处理组,OCDF对紫茉莉地上生物量无显著抑制作用,反而某些处理组增加紫茉莉地上生物量.Cd-OCDF复合污染效应与Cd单一污染相比,Cd浓度为200 mg·kg-1,OCDF浓度为100μg·kg-1时,紫茉莉根部Cd积累量降低了34.44%,Cd浓度为400 mg·kg-1,OCDF浓度为100μg·kg-1时,根部和叶部Cd积累量分别降低了7.93%和18.09%;其它处理组,OCDF不同程度地提高了紫茉莉根、茎、叶提取和积累土壤中Cd的能力.可见,用紫茉莉修复高浓度Cd-OCDF复合污染土壤中的Cd具有实践上的可行性.

Soil contamination by heavy metals and persistent organic pollutants tends to be severe. Pot experiment was conducted to investigate the phytoremediation of cadmium(Cd) in Cd-OCDF Co-contaminated Soil by Mirabilis jalapa L. , using OCDF and Cd as the model pollutants of persistent organic pollutants and heavy metals, to study the growth responses of plant and OCDF effects on phytoremediation of Cd. The results showed that during three months of planting the height and dry biomass of Mirabilis jalapa L. decreased slightly when the Cd concentration was not higher than 200 mg·kg - 1 , and the plant exhibited high tolerance to Cd and OCDF. Compared with the Cd single pollution, OCDF had no significant effect on the height and root biomass of Mirabilis jalapa L. . When the concentration of Cd was 200 mg·kg - 1 and the concentration of OCDF was 500 μg·kg - 1 , the shoot biomass was reduced by 22. 19% . In other treatments, OCDF showed no significant inhibition to the shoot biomass of Mirabilis jalapa L. , but increased the shoot biomass in some treatments. Compared with single Cd pollution, when the concentration of Cd was 200 mg·kg - 1 and the concentration of OCDF was 100 μg·kg - 1 , the Cd accumulation of root was reduced by 34. 44% . When the concentration of Cd was 400 mg·kg - 1 and the concentration of OCDF was 100 μg·kg - 1 , the Cd accumulation in root and leaf was reduced by 7. 93% and 18. 09% , respectively. In other treatments, OCDF promoted the extraction and accumulation of Cd by root, stem and leaf of Mirabilis jalapa L. from soil to some degree. So using Mirabilis jalapa L. to remediate Cd from high Cd concentration and OCDF co-contaminated soil is feasible.