外源营养调控对石油污染土壤微生物修复的强化机制研究OA

Imbalanced C/N/P ratio in petroleum-contaminated soil is a key factor restricting microbial remediation efficiency.Using the high-efficiency composite degrading bacterial agent M(Bacillus sp.J1-8 and Pseudomonas aeruginosa J6-7 blended at volume ratio of 1:3)developed in previous research as the test strain,this paper systematically investigates the influences of exogenous nutrient regulation on petroleum hydrocarbon degradation,and reveals the variation of soil nutrient content and response characteristics of dehydrogenase activity during remediation.The results show that among six nitrogen and phosphorus combinations,the mixture of NH4Cl and KH2PO4 achieves optimal performance with a 20-day degradation rate of 58.43％.After further optimization of molar C:N:P ratio(calculated by TOC),the maximum degradation rate of 63.32％is obtained at 100:12,rising by 19.19％compared with the blank group,and the dehydrogenase activity reaches 1.53 µg TF/(g·h).Variation of soil nutrients indicates nitrification occurs during remediation;available nitrogen is consumed faster than available phosphorus,leading to an upward N/P ratio over time.To tackle nutrient deficiency in later degradation stage,supplementary feeding interval is optimized,and nutrient addition every 12 days is proven optimal,raising the 30-day degradation rate to 72.12％with peak dehydrogenase activity of 1.74 µg TF/(g·h).This research provides systematic technical solutions and theoretical support for nutrient management in microbial remediation of petroleum-polluted soil.