秸秆载体腐解对微生物修复石油污染的影响

Effect of Straw Carrier Decomposition on Remediation of Petroleum Contaminated Soil by Microorganism

以一种农作物秸秆(简称MG)为载体,采用高效石油烃降解菌群制备固定化微生物,在花盆中模拟石油污染土壤的原位修复。在污染土壤中分别加入秸秆(MG)、游离菌、秸秆(MG)+游离菌、秸秆(MG)固定化微生物,并以只含土著菌的土壤样品为对照,定期测定不同修复方式下土样中石油烃、腐殖质、胡敏酸含量和微生物数量,考察微生物对石油污染土壤的修复作用及MG腐解对修复的影响。结果表明,随着修复的进行,MG在土壤中逐渐腐解,土壤中腐殖质和胡敏酸质量分数明显增高,加入固定化微生物的土样中腐殖质和胡敏酸质量分数增长率最高,分别增加了44.58%和39.27%;加入固定化微生物的土样修复35d的石油烃降解率最高,达到41.78%,且微生物数量最多,其次为添加MG+游离菌的土样,石油烃降解率为31.75%,均高于只含游离菌土样的石油烃降解率27.83%。载体MG腐解产生的腐殖质和胡敏酸对石油污染土壤的修复起到了明显的促进作用。

The immobilized microorganism was prepared by highly efficiency petroleum hydrocarbon degrading bacteria and straw carrier material MG, and used to simulate the in situ remediation of petroleum contaminated soil. The MG, free bacteria, MG plus free bacteria, immobilized microorganism were added into petroleum contaminated soil, respectively, and a control group containing only indigenous bacteria was set up. The content of petroleum hydrocarbons, humic substances, humic acid and the microbe quantity in the soil of different remediation methods were determined at set intervals to investigate the effect of microorganism on petroleum contaminated soil and the effect of MG decomposition on the remediation. The results showed that MG in the soil gradually decomposed along with the restoration, causing the increases of humic substances and humic acid contents in soil obviously. The increasing rates of humic substances and humic acid mass fraction of petroleum contaminated soil with the addition of immobilized microorganism were 44.58% and 39.27%, respectively, both were the highest values among these remediation methods. The highest degradation rate of 41. 78% for 35 d remediation of petroleum contaminated soil with immobilized microorganism and the most microorganism number were obtained, and next one was the petroleum contaminated soil containing MG plus free bacteria, with the petroleum hydrocarbon degradation rate of 31. 75%, higher than 27. 83% of the petroleum contaminated soil containing free bacteria added only. Humic substances and humic acid produced in decomposition of MG have significant effect on the remediation of oil contaminated soil.