响应曲面法优化A^2O/MBR工艺处理煤气化废水

Optimization of A^2O/MBR Combined Process for Treating Coal Gasification Wastewater by Response Surface Methodology

利用A^2O/MBR组合工艺处理模拟煤气化废水,为了更好地优化和预测该工艺的最佳运行参数,通过引进二次回归正交旋转组合设计和响应曲面法研究了混合液回流比、曝气量和碱度剂量率(废水中Na HCO_3和NH_4^+-N的质量比)对TN和TOC去除率的影响。结果表明,以上三个因素对TN去除率有非常显著的影响,而对TOC去除率的影响很小(去除率始终大于95%);通过对回归方程的方差分析、失拟性检验以及对模型预测值和实测值的比较,证明回归模型对实际情况拟合较好,回归方程有统计学意义。此外,利用回归方程进行规划求解预测该组合工艺的最佳运行条件如下:混合液回流比为2.33,曝气量为1.34 L/min,碱度剂量率为13.49,此时TN去除率的预测值为92.55%,该预测值得到了进一步的试验验证。

The A2O/MBR combined process was employed to treat simulated coal gasification wastewater. Utilizing the quadratic orthogonal rotatory combination design and the response surface meth- odology, a regression model between the return mixed liquid ratio （R）, the aeration rate and the alkalini- ty dose rate（ mass ratio of NaHCO3 to NH4 -N） , and TN and TOC removal efficiencies was established to optimize and predict the best performance of the combined process. The experiment results showed that the three factors had significant impacts on the TN removal rate, but minimum impacts on the TOC re- moval rate, which was always higher than 95 %. The regression model was in good agreement with the ob- servations, and the regression equation provided statistical significance which was revealed in the ANOVA analysis, the lack of fitness tests and the comparison between the observed and the predicted data. In ad- dition, the optimum values of the reaction parameters were obtained through adopting linear programming solutions： R = 2.33, aeration rate of 1.34 L/min, and alkalinity dose rate of 13.49, with the TN remov- al rate of 92.55%. The optimum conditions was validated through experiments.