螯合剂和表面活性剂辅助金福菇修复重金属污染土壤

通过温室大棚盆栽试验,研究螯合剂和表面活性剂单独或复合处理辅助金福菇修复重金属污染土壤的效果.结果表明,单独添加EDTA(乙二胺四乙酸)时,高浓度的EDTA(E2,5 mmol kg-1)使金福菇的生物量比对照降低26%,子实体Pb、Cu和Cd的浓度分别比对照提高15～88倍、0.8～3.3倍和0.5～0.6倍.单独添加表面活性剂时,各处理生物量与对照没有显著差异,且重金属浓度变化幅度没有单独添加EDTA的处理大.低浓度的表面活性剂对金福菇吸收各种重金属的影响较小,而高浓度则影响较大,但与表面活性剂及重金属种类有关.共同添加EDTA和表面活性剂时,只有当EDTA和CTAB(溴化十六烷基三甲铵)共同添加时,EC2(EDTA:CTAB=1:1)和EC3(EDTA:CTAB=2:1)的生物量显著降低,其余处理与对照差异不明显.EC3的子实体Pb和Cu浓度达到所有处理中的最大值,分别为(1 533.61±131.34)、(1 786.11±328.33)mg kg-1.EDTA和SDS(十二烷基磺酸钠)浓度比为2:1(ES3)时,子实体Cd浓度达到最大值,为(50.56±11.55)mg kg-1.此外,还分析了不同处理的重金属总积累量和富集系数.结果显示,在螯合剂和表面活性剂辅助下,金福菇修复复合重金属污染土壤具有很大的潜能.

Chelator-and Surfactant-assisted Remediation of Heavy Metal Contaminated Soil by Tricholoma lobayense Heim

The influence of chelators and surfactants on bioaccumulation of heavy metals in mushroom(Tricholoma lobayense Heim) from multiple-contaminated soil was studied with pot experiments in greenhouse.The results showed that high concentration of EDTA(E2,5 mmol kg-1) reduced the mushroom biomass by 26%,and the concentrations of Pb,Cu,Cd in the fruiting bodies increased by 15~88,0.8~3.3,0.5~0.6 times respectively when only EDTA was added.There were no significant differences in biomass between the treated pots and the control pots when only surfactants were added,and the variance in heavy metal concentrations was less than those with EDTA additions.Surfactants did not change the bioaccumulation of heavy metals in mushroom when the concentration was low,but high concentration of surfactant caused a much significant influence on the metal uptakes,depending on the kinds of surfactants and heavy metals.When EDTA was added together with surfactants,only the EDTA plus CTAB combinations at the ratios of 1 : 1 or 2 : 1(EC2 or EC3) applied to the soil,the biomasses of the mushroom significantly were decreased.In treatment EC3,the concentrations of Pb and Cu in fruiting bodies reached the highest,which were(1533.61 ± 131.34) and(1786.11 ± 328.33) mg kg-1,respectively.When the concentration ratio of EDTA and SDS was 2 : 1(ES3),Cd concentration in fruiting body reached 50.56 ± 11.55 mg kg-1,which was the highest in all the samples.Interestingly,many mushrooms turned blue after the soil was treated with chelators or surfactants,indicating abundant Cu in them.The total estimated metal uptakes and the bioaccumulation efficiencies suggested that the mushroom(T.lobayense) would be an effective bio-extractor which can be applied to remediate multiple-contaminated soil with the help of chelators and surfactants.