聚硅基复合氯化铁絮凝剂的制备及其在采油废水处理中的应用

采用硅酸钠制备聚硅酸,探讨了活化pH、活化剂、硅酸钠浓度(以SiO_2质量分数计)及聚合温度等因素对聚硅酸稳定性的影响.利用聚硅酸及氯化铁制备聚硅基复合氯化铁(PSiF),并通过正交试验分析了活化pH、Si/Fe(摩尔比)、OH/Fe(摩尔比)、制备时间对PSiF絮凝性能的影响.综合考虑絮凝性能、稳定性以及经济性等因素,确定PSiF适宜的制备条件为SiO_2质量分数2%～3%;活化pH为2～3;Si/Fe为0.50～0.75;OH/Fe为0.50～0.75;制备时间为0.5 h;聚合温度低于25℃.对比PSiF、PAC、FeCl_3对采油废水的处理效果,PSiF除浊、除COD效果以及经济性最好,是一种应用前景广阔的新型絮凝剂.

Preparation of ferrie-polysilicate (PSiF) coagulant and its application in oil-field wastewater treatment

The polymerized silicic acid was prepared with sodium silicate as raw material, and the effect of pH, acidifi-ers, SiO_2 concentration and temperature on viscosity and stability of poly silicic acid was investigated. Employing the obtained polymerized silicic acid for the preparation of ferric-polysilicate (PSiF) coagulant, the influences of major parameters, inclu-ding pH, Si/Fe (molar ratio), OH/Fe(molar ratio), preparing time, were analyzed by orthonorrnal experiment, and the op-timurn PSiF preparing conditions were obtained as follow:SiO_2 concentration ranged 2%-3%, pH ranged 2-3, molar ratio of OH/Fe and Si/Fe ranged 0. 50-0. 75, preparing time of 0. 5 h and temperature lower than 25℃. 3 coagulations of PSiF,PAC and FeCl_3 were employed for the treatment of oil-field wastewater, the PSiF exhibited best performance on turbidity and COD removal, which proved that PSiF was found to be a new promising coagulant.