“三气”合采产出水的加载絮凝预处理响应面优化

Optimization of loading flocculation pretreatment of produced water from“three gases”co-mining using response surface methodology

为了提高煤系"三气"合采产出水水质,采用响应面方法研究优化了加载絮凝预处理的效果。通过BoxBehnken实验设计,选取PFS投加量、APAM投加量、污泥回流量为主要影响因素,以COD去除率为响应值,建立相关数学模型,并对模型进行优化分析和实验验证。结果表明,根据实验数据建立的二次多项式数学模型具有高度显著性(P<0.0001),决定系数R^(2)=0.987,实验值和预测值之间具有很好的拟合度。得到的最佳工艺条件为PFS投加量28.88 mg·L^(-1)、APAM投加量9.96 mg·L^(-1)、回流污泥量为239.5 mg·L^(-1)。在此条件下,COD去除率预测值为37.32%,实测值为37.41%,二者偏差为0.09%。Zeta电位降为-4.08 mV。系统处理后出水可达标回用于相关旱作农田灌溉,这对于产出水的资源化利用具有重要意义。

In order to improve the produced water quality from"three gas"co-mining in coal measures,response surface method was used to study and optimize the effect of loading flocculation pretreatment.Through the Box-Behnken test design,PFS dosage,APAM dosage and sludge return flow were chosen as the main influencing factors,and COD removal rate was taken as the response index to establish the relevant mathematical model,then the optimization analysis and test verification of the model was conducted.The results showed that the quadratic polynomial mathematical model based on the experimental data was highly significant(P<0.0001),with R^(2)=0.987.Good fitting occurred between the experimental data and predicted data.The optimal process conditions were PFS dosage of 28.88 mg·L^(-1),APAM dosage of 9.96 mg·L^(-1) and reflux sludge of 239.5 mg·L^(-1).Under these conditions,the predicted value of COD removal rate was 37.32%,the measured value was 37.41%,with the deviation of 0.09%between them.Zeta potential decreased to-4.08 mV.After the system treatment,the effluent can meet the reuse standard for irrigation of relevant dry farmland,it is of great significance for the resource utilization of the produced water.