Lelliottia sp.Kz9与纳米零价铁强化印度芥菜修复土壤镉污染

Remediation of Cd-pulluted Soil by Lelliottia sp.Kz9 and Nanoscale Zerovalent Iron Assisted by Brassica j uncea to Cd-polluted Soil

利用植物富集土壤中重金属,是进行重金属污染土壤生态修复的一种重要手段。重金属抑制植物的生长发育,导致植株矮小、生物量较低,是植物生态修复的难点。通过盆栽试验,探究根际促生菌(Lelliottia sp.Kz9)和100 nm纳米零价铁(nZVI_(100))单一或联合施用对不同浓度镉污染土壤中印度芥菜的生长及富集重金属的影响。结果表明:nZVI_(100)在低浓度(5 mg/kg)镉胁迫下可显著促进印度芥菜的生物量、根系发育,以及地上部分镉和铁的吸收(p<0.05),nZVI_(100)在高浓度(20 mg/kg)镉胁迫下可显著提高印度芥菜的生物量、根系发育和地上部分铁的吸收(p<0.05);联合施用Kz9和nZVI_(100)对不同浓度镉污染土壤印度芥菜叶片中叶绿素含量和铁吸收均有显著促进作用(p<0.01);不同浓度镉污染土壤中印度芥菜受Kz9和nZVI_(100)的正向影响依次为nZVI_(100)处理组>Kz9与nZVI_(100)联合处理组>Kz9处理组,表明nZVI_(100)在土壤重金属污染生态修复技术应用方面有较好的前景。

Using plants to accumulate heavy metals in soil is an important strategy o£soil ecological restoration.However,heavy metals inhibit the growth and development of plants,resulting in dwarf plants and low biomass.Our study explores the effects of individual or combined application of plant growth-promoting rhizobacteria(PGPR>Lelliottia sp.Kz9)and 100 nm nanoscale zerovalent iron(nZVI_(100))on plant growth and metal accumulation in different concentrations of cadmium-contaminated soil through pot experiments.The results show that the treatment of nZVI_(100) at low cadmium level(5 mg/kg)could significantly improve biomass,root morphological development and content of cadmium and iron in shoots(P><0.05);at high cadmium level(20 mg/kg)significantly enhance plant biomass,root morphological development and iron uptake of shoots(P>0.05);the combined application of Kz9 and nZVI_(100) positively affect chlorophyll content and iron absorption of B.juncea(Q<0.01).The positive effects of Kz9 and nZVI_(100) on B.juncea in different concentrations of cadmium-contaminated soil are as follows:nZVI_(100) treatments>combined Kz9 and nZVI_(100) treatments〉Kz9 treatments,indicating that nZVI_(100) has a good prospect in the application of heavy metal pollution ecological res to ration technology in soil.