植物生长调节剂胺鲜酯与螯合剂EDDS/MGDA对黑麦草修复Cd污染农田土壤的作用

Remediation Effect of Plant Growth Regulator Diethylaminoethyl Hexanoate and Chelating Agent EDDS/MGDA on Cd Contaminated Farmland Soil

采用盆栽土培法研究植物生长调节剂胺鲜酯和螯合剂EDDS/MGDA对Cd污染农田土壤植物修复的强化性能及其作用。结果表明:胺鲜酯或EDDS/MGDA单独作用均可增加根际和非根际土壤中酸溶态Cd含量,促进黑麦草对Cd的富集,但EDDS/MGDA使黑麦草根长和地上部分烘干质量显著下降(P<0.05),而胺鲜酯显著提高黑麦草生物量(P<0.05)。胺鲜酯与EDDS/MGDA联合作用时进一步强化黑麦草对Cd的富集(P<0.05)。MGDA与胺鲜酯联用时黑麦草Cd的提取效率高于EDDS与胺鲜酯联合处理,其中1μmol胺鲜酯+5mmol/kgMGDA使在种植于25mg/kg,50mg/kgCd土壤的黑麦草45d地上部分Cd浓度分别达到91.0mg/kg.165.7mg/kg,Cd提取效率分别为2.2%、1.7%,可在农田土壤Cd污染的植物修复中作为强化措施。

A pot experiment was conducted to study the function of EDDS/MGDA as chelator and diethylaminoethyl hexanoate as the plant grow regulator and their effect on enhancing the phytoremediation of Cd contaminated soil.The results showed that the sole addition of diethylaminoethyl hexanoate or EDDS/MGDA could both increase the acid soluble Cd proportion in rhizosphere soil and non-rhizosphere soil,and promote the Cd enrichment by Lolium perenn.With the treatment of EDDS/MGDA,the root length and shoot dry biomass were reduced significantly(P<0.05),while diethylaminoethyl hexanoate increased the biomass of Lolium perenn(P<0.05).The combination of diethylaminoethyl hexanoate and EDDS/MGDA furtherly promoted the Cd enrichment by Lolium perenn.In addition,the treatment of diethylaminoethyl hexanoate combined with MGDA was more efficient to extract Cd than that of diethylaminoethyl hexanoate combined with EDDS.The Cd concentration aboveground reached 91.0 mg/kg and 165.7 mg/kg respectively under the 45d's treatment of 1μmol diethylaminoethyl hexanoate and 5 mmol/kg MGDA when the Cd concentration of the soil was 25 mg/kg or 50 mg/kg.Meanwhile the corresponding extraction efficiency of Cd reached 2.2%and 1.7%,which could be used in phytoremediation of the Cd contaminated soil.