【摘要】 土壤多环芳烃(PAHs)的污染已经成为了全球性的热点问题,微生物-植物联合修复技术是解决土壤有机污染的一种低耗高效的新型修复技术。以往作为目标污染物,绿豆根瘤菌(Rhizobium leguminosarum),紫花苜宿根瘤菌(Rhizobium meliloti)为供试微生物,选用绿豆(Vigna radiata L.)、紫花苜蓿(Medicago sativa L.),黑麦草(Lolium perenne L.)和花生(Arachis hypogaea L.)作为修复植物。采用盆栽实验,研究在100 mg·kg-1污染条件下,接种根瘤菌对植物修复法污染土壤效果的影响。结果表明:培养60d后,4种植物均提高了芘污染土壤的pH,并提高了土壤脱氢酶的活性,其中种植绿豆的效果最好,其次为花生。此外,4种植物均提高了土壤中芘的去除率,提高幅度依次为绿豆(33.70%)>花生(21.63%)>黑麦草(10.55%)>苜蓿(7.72%)。接种根瘤菌后发现,绿豆和花生根瘤数显著高于对照组,苜蓿与根瘤菌没有结合,而黑麦草则不和根瘤菌共生。根瘤菌对土壤中pH有一定的提高作用,但效果不显著。此外,根瘤菌提高了绿豆、花生和紫花苜蓿的生物量以及绿豆和花生处理组土壤的脱氢酶活性。并提高了绿豆和花生对土壤中芘的去除率,分别为4.10%和2.02%。研究表明:种植绿豆对土壤芘的去除率最高(94.63%),根瘤菌能与其根系结合良好,强化了绿豆修复芘污染土壤的能力,结果可为微生物-植物修复芘污染土壤提供新的参考。更多还原

【Abstract】 The issue of PAHs(Polycyclic Aromatic Hydrocarbon)contamination has raised global concern.It is an effective way to solve this problem by using microbial-plant remediation technology,which has the characters of low cost.In this study,pyrene was chosen as the target pollutant.Mung bean,peanut,alfalfa and ryegrass were inoculated with rhizobium,respectively,to investigate effect of rhizobium on phytoremediation in pyrene contaminated soil by conducting a pot experiment.The results suggested that these four plants could improve soil pH and increase dehydrogenase activity in contaminated soil,and best results was obtained in mung bean treatment.Moreover,higher pyrene degradation rate could be observed in the presence of plants,and followed the order of mung bean>peanut>ryegrass>alfalfa.After inoculating rhizobium,more root nodules can be observed in mung bean and peanut treatments when compared with that in the non-inoculated group,while alfalfa and ryegrass were not successfully inoculated with rhizobium.In addition,rhizobium improved soil pH,but the change was not significant.Further,rhizobium increased biomass in mung bean,peanut and alfalfa.Meanwhile,rhizobium also increased soil dehydrogenase activity in mung bean and peanut treatments.Finally,rhizobium improved soil pyrene degradation rates by 4.10% and 2.02% in mung bean and peanut treatments,respectively.This study revealed that mung bean can remove pyrene efficiently with highest degradation rate of 94.63%,and inoculating rhizobium strengthened the degradation rate.The results can provide a new reference for microorganism-plant remediation of pyrene contaminated soil.更多还原