Laboratory of Wastewater Treatment, Water Research and Technologies Centre (CERTE), Technopole of Borj Cedria, BP 273, Soliman, 8020, Tunisia,
Environ Sci Pollut Res Int. 2014 Jan;21(2):1304-13. doi: 10.1007/s11356-013-1997-y. Epub 2013 Jul 31.
Pot-culture experiments were conducted to evaluate the phytoremediation potential of a wetland plant species, Phragmites australis in cadmium (Cd) and pentachlorophenol (PCP) co-contaminated soil under glasshouse conditions for 70 days. The treatments included Cd (0, 5 and 50 mg kg(-1)) without or with PCP (50 and 250 mg kg(-1)). The results showed that growth of P. australis was significantly influenced by interaction of Cd and PCP, decreasing with either Cd or PCP additions. Plant biomass was inhibited and reduced by the rate of 89 and 92% in the low and high Cd treatments and by 20 and 40% in the low and high PCP treatments compared to the control. The mixture of low Cd and low PCP lessened Cd toxicity to plants, resulting in improved plant growth (by 144%). Under the joint stress of the two contaminants, the ability of Cd uptake and translocation by P. australis was weak, and the BF and TF values were inferior to 1.0. A low proportion of the metal is found aboveground in comparison to roots, indicating a restriction on transport upwards and an excluding effect on Cd uptake. Thus, P. australis cannot be useful for phytoextraction. The removal rate of PCP increased significantly (70%) in planted soil. Significant positive correlations were found between the DHA and the removal of PCP in planted soils which implied that plant root exudates promote the rhizosphere microorganisms and enzyme activity, thereby improving biodegradation of PCP. Based on results, P. australis cannot be effective for phytoremediation of soil co-contaminated with Cd and PCP. Further, high levels of pollutant hamper and eventually inhibit plant growth. Therefore, developing supplementary methods (e.g. exploring the partnership of plant-microbe) for either enhancing (phytoextraction) or reducing the bioavailability of contaminants in the rhizosphere (phytostabilization) as well as plant growth promoting could significantly improve the process of phytoremediation in co-contaminated soil.
进行了盆栽实验，以评估湿地植物芦苇（Phragmites australis）在温室条件下 70 天内对镉（Cd）和五氯苯酚（PCP）复合污染土壤的植物修复潜力。处理包括无 Cd 或有 Cd（5 和 50mgkg(-1)），以及无 PCP 或有 PCP（50 和 250mgkg(-1)）。结果表明，Cd 和 PCP 的相互作用显著影响芦苇的生长，随着 Cd 或 PCP 的添加，植物生物量受到抑制和减少。与对照相比，低 Cd 和高 Cd 处理分别使植物生物量减少 89%和 92%，低 PCP 和高 PCP 处理分别减少 20%和 40%。低 Cd 和低 PCP 的混合物减轻了 Cd 对植物的毒性，使植物生长提高了 144%。在两种污染物的联合胁迫下，芦苇对 Cd 的吸收和转运能力较弱，BF 和 TF 值均低于 1.0。与根部相比，地上部分的金属比例较低，表明向上运输受到限制，对 Cd 吸收具有排斥作用。因此，芦苇不能用于植物提取。种植土壤中 PCP 的去除率显著增加（70%）。种植土壤中 DHA 与 PCP 去除率之间存在显著正相关，这表明植物根系分泌物促进了根际微生物和酶活性，从而提高了 PCP 的生物降解。基于这些结果，芦苇不能有效地用于修复同时受到 Cd 和 PCP 污染的土壤。此外，高浓度的污染物会阻碍并最终抑制植物的生长。因此，开发补充方法（例如，探索植物-微生物的伙伴关系）来增强（植物提取）或降低根际污染物的生物有效性（植物稳定化）以及促进植物生长，可以显著改善复合污染土壤的植物修复过程。
