响应面法优化固定化微生物降解石油污染物

从炼油厂活性污泥中筛选和驯化了1株石油降解菌SJ-1，以秸秆材料WT为固定化载体，采用表面吸附法制备固定化微生物；以胜利原油为反应底物，考察了温度、微生物接种量、原油质量浓度、pH值对原油降解率的影响；采用响应面法优化了降解条件，并在优化条件下进行了降解动力学实验。结果表明，单因素对降解率的影响程度从大到小的顺序为温度、pH值、原油质量浓度、接种量，其中pH值和原油质量浓度、原油质量浓度和温度的交互影响对原油降解率影响较显著；根据响应面模型计算得到的最佳降解条件为pH值7.0、原油质量浓度5000 mg/L、温度34℃、接种量46 g/L，此时原油降解率最高达68.3%；固定化微生物和游离微生物降解过程均符合一级动力学，且前者的降解速率是后者的3.67倍。

Optimization for Oil Degradation by Immobilized Microorganism Through Response Surface

SJ-1, a petroleum degradation strain selected and domesticated from oil refinery active sludge was employed to produce immobilized microorganism with WT, a straw material in adsorption. Crude oil from Shengli oil field was chosen as response substance. The factors influencing oil degradation rate was studied, including the temperature, inoculation amount, crude oil initial mass concentration and pH value. Also, response surface methodology was used to optimize the degradation conditions. Degradation dynamics experiment was also studied under the optimal conditions. The results showed that the influence degree of the single factor to the oil degradation rate from large to small was temperature, pH value, crude oil initial mass concentration and inoculation amount. The interplay of pH value and crude oil initial mass concentration, crude oil initial mass concentration and temperature remarkably influenced the oil degradation rate. The best degradation rate of 68.3% was obtained under the conditions(calculated according to the response surface model) of pH value 7.0, the crude oil initial mass concentration 5000 mg/L, the inoculation amount 46 g/L and the temperature 34℃. The degradation process of immobilized and free microorganism accorded with first order-kinetic equation, and the degradation speed of immobilized microorganism was 3.67 times of that of free microbes.