絮凝菌处理页岩气压裂返排液的响应面优化

采用实验室已经筛选出的具有絮凝活性的菌株，考察发酵培养时间对絮凝效果的影响，并进行絮凝性能测定。测定结果表明，菌株H5为Acinetobacter baumannii strain，发酵培养36 h时，其絮凝率可达到65.7%。采用絮凝菌与PAC复配的方法处理页岩气压裂返排液，并且应用响应面分析法对处理过程进行了优化。设定响应值为COD去除率，根据响应值的分布情况确定最佳絮凝条件为：絮凝菌H5的投加量10 mg/L；PAC浓度30 mg/L；慢速搅拌速度73 r/min；沉降时间40 min。最佳絮凝条件下，联合处理对压裂返排液中COD去除率为85.1%，浊度去除率95%以上。

Response Surface Methodology Optimization of Bacterial Flocculation Treatment for Shale Gas Fracturing Fluids

A bacterial strain with flocculation activity, which was screened in our laboratory, was used to examine the effects of duration of fermentation on flocculation. Results showed that when strain H5 (Acinetobacter baumannii strain) was used for fermentation for 36 h, the flocculation was 65.7%. he flocculating bacteria and polyaluminium chloride (PAC) were used to treat shale gas fracturing flowback fluid, and response surface methodology was used for optimization of the treatment process, using COD removal rate as the response variable. According to the distribution of response values, the optimal flocculation conditions were as follows:Addition of 10 mg/L of flocculating bacteria H5, PAC concentration of 30 mg/L, slow stirring speed of 73 r/min, and a sedimentation period of 40 minutes. Under optimal flocculation conditions, the COD removal rate was 85.1% and turbidity removal rate was more than 95.0% when combined treatment was used on shale gas fracturing fluids.