海藻酸钠-聚合氯化铝复配混凝剂应用于电厂原水预处理的研究

Study on Application of Alginate-Polyaluminum Chloride Compound Coagulant in Power Plant Raw Water Pretreatment

选取聚合氯化铝(PAC)和海藻酸钠(SA)进行复配得到高效复配混凝剂(PAC-SA)用来处理长春某热电厂原水(水库水),确定夏季PAC-SA的最佳加药量和pH区间,探讨了不同加药量和温度下剩余浊度和余铝的变化,计算了投加PACSA最佳处理效果下的G值和Gt值。结果表明:热电厂原水浊度小于50NTU时,PAC-SA的最佳加药量为:PAC浓度10mg/L,SA浓度1mg/L进行复配,最佳pH为8.3左右,当PAC-SA为最佳加药量时,剩余浊度为2.3NTU,余铝为0.56mg/L,而同条件下仅投加PAC剩余浊度为5.5NTU,余铝为0.95mg/L,快速搅拌时G值为410.5S^-1,Gt值为3.22×10^4;慢速搅拌时G值为44.2S^-1,Gt值为4.51×10^4,符合根据工程经验综合考虑搅拌强度和时间后最佳絮凝效果Gt值区间之内。

Poly aluminum chloride(hereinafter referred to as PVC)and sodium alginate(hereinafter referred to as SA)are compounded to obtain a highly effective compound coagulant(hereinafter referred to as PVC-SA)for the treatment of raw water(reservoir water)of a thermal power plant in Changchun,Determine the optimal dosage and pH range of PVC-SA in summer,discuss the changes of residual turbidity and residual aluminum at different dosages and temperatures,and calculate the G value and the optimal treatment effect of PVC-SA.Gt value.The results show that when the raw water turbidity of the thermal power plant is less than 50NTU,the optimal dosage of PVC-SA is PVC concentration:10mg/L,SA concentration:1mg/L.The optimal pH value is about 8.3.When PVC-SA For the best dosage,the remaining turbidity is 2.3NTU and the residual aluminum is 0.56mg/L.Under the same conditions,the remaining turbidity of PVC is 5.5NTU and the remaining aluminum is 0.95mg/L.G The value is 410.5S^-1,Gt value is 3.22×10^4;G value is 44.2S^-1 and Gt value is 4.51×10^4 during slow stirring,which is within the range of Gt value of the best flocculation effect after comprehensive consideration of stirring strength and time based on engineering experience.