响应面法分析Fenton氧化处理采油废水的过程

Application of response surface methodology to treatment of oil recovery wastewater processing using Fenton oxidation

采用Fenton氧化对采油废水进行研究,选取双氧水与二价铁离子的摩尔比、初始p H值和反应时间为自变量,以废水的COD去除率为响应值,通过Box-Behnken设计方法进行实验设计,进行了3因素3水平共15个实验点的实验。使用响应面分析法对实验结果进行模拟及分析,建立了响应值与3个自变量的二次多项式方程模型。Fenton氧化的优化工艺条件:n(H2O2)∶n(Fe2+)=0.8,p H=3.0以及反应时间60 min。在该优化条件下,废水的COD去除率可达72.8%,经实验验证,实际值与模型预测值拟合性好,偏差仅为0.5%。实验结果证实了该模型分析采油废水处理运行参数的准确性。优化工艺后的处理水质COD值完全满足油田废水达标排放的要求。通过总离子色谱图和质谱检索分析原油中的成分变化情况,证实Fenton方法对原油组分的降解效果。

Fenton oxidation was employed to treat oil recovery wastewater. The H2O2/ Fe2 ＋mole ratio,initial pH value,and reaction time were selected as independent variables; COD removal rate of wastewater was selected as the response value. A Box-Behnken design was employed for the experimental design,of which an experimental matrix of three-factorial,three-level experimental design consisting of 15 experimental runs was conducted. Experimental results were simulated and analyzed by response surface methodology. A quadratic polynomial equation was constructed to describe the relationship between COD removal rate and three variables. The optimum conditions of Fenton oxidation were determined to be a H2O2/ Fe^2 ＋mole ratio of 0. 8,initial pH value of3. 0,and reaction time of 60 min. The removal rate of COD was up to 72. 8% under the optimal conditions. The actual value agreed with the predicted value from the model equation with only 0. 5% deviation. The results confirmed that the proposed models were accurate and reliable for the analysis of the variables of wastewater treatment. Furthermore,the COD of the treated water could meet the discharge standard in oilfields. The change of organic composition was reflected in the total ion chromatogram and mass spectrometry,which can be used to confirm the degradation effect of oil by the Fenton method.