紫花苜蓿-铜绿假单胞菌联合修复石油污染土壤

选择紫花苜蓿协同铜绿假单胞菌进行石油污染土壤修复，探究植物-微生物联合修复石油污染土壤的效果及作用机理，并考察了石油初始含量、植株种植密度、菌剂投加量及营养物对紫花苜蓿-铜绿假单胞菌联合修复效果的影响。结果显示，紫花苜蓿-铜绿假单胞菌联合修复效果明显优于单一紫花苜蓿或铜绿假单胞菌修复，经过56 d的修复，土壤中石油的去除率高达72%。在联合修复体系中，植物与微生物表现出明显的互生作用。当污染土壤中石油初始质量分数为0.6%，紫花苜蓿种植密度为20棵/dm²，土壤中铜绿假单胞菌菌剂投加量为20 g/kg时，污染土壤的修复效果最佳且修复体系能够得以充分利用。适量的氮、磷营养物添加可进一步改善紫花苜蓿-铜绿假单胞菌联合修复效果。

Remediation of Petroleum Contaminated Soil by Alfalfa and Pseudomonas Aeruginosa

To explore the effect and mechanism of plant microbe remediation of petroleum contaminated soil, Alfalfa and Pseudomonas aeruginosa were selected to remediate petroleum contaminated soil in a combined way. Additionally, the influences of initial petroleum content, planting density of Alfalfa, dosage of Pseudomonas aeruginosa agent and nutrients on the combined remediation effect of Alfalfa and Pseudomonas aeruginosa were investigated. The results show that the effect of combined remediation by Alfalfa and Pseudomonas aeruginosa is significantly better than that of remediation merely by Alfalfa or Pseudomonas aeruginosa. After 56 days of remediation, up to 72% of petroleum can be removed from soil. In the combined remediation system, plants and microbes present significant protocooperation relationship. When the initial petroleum mass fraction is 0.6%, the planting density of Alfalfa is 20 seeds/dm² and the dosage of Pseudomonas aeruginosa agent is 20 g/（kg soil）, the remediation effect is the best and the remediation system can be fully utilized. Moreover, appropriate addition of nitrogen and phosphorus nutrients can further improve the combined remediation effect of Alfalfa and Pseudomonas aeruginosa.