复合钛盐混凝剂的制备及其除砷效果的研究

Preparation of titanium salt coagulant and their properties for arsenic removal

采用简单的水解方法制备了一种新型复合钛铁混凝剂,用于去除饮用水中的砷。考察了pH值、混凝剂投加量、砷初始浓度、水力条件和共存离子等因素对砷去除效果的影响。结果表明,在pH=7,原水砷浓度为0.150mg/L,2#混凝剂投加量为10mg/L时,可使滤后水中砷浓度为8.44μg/L(<10μg/L);混凝剂加入量为10mg/L,对较高浓度的As(Ⅲ)仍具有很高的去除率,可使含砷量为0.500mg/L的原水去除率达到89.81%。水力条件对除砷效果的影响不大;混凝除砷的适宜pH为6～8;碳酸根(HCO3-)和磷酸根(H2PO42-)等共存离子对砷的去除有一定的抑制作用。

An innovative Ti--Fe coagulant for removal of arsenic from drinking water was prepared by hydrolysis method. The effects of pH, dosage of the coagulant, initial concentration of arsenic, hydrodynamic condition and coexistent ions on removal efficiency were discussed. The results show that under the condition of pH=7 and dosage of coagulant 10mg/L, the residual concentration of arsenic in treated water was 8.44μg/L （lower than 10μg/L） with initial concentration of arsenic at 0. 150mg/L. There is still very high removal rate achieved 89.81% with the dosage of coagulant 10mg/L under a high concentration of As（I]I） at 0. 500mg/L. The hydrodynamic condition has no significant effect on the removal of arsenic. The fitting coagulation pH is 6-8. Coexistent ions such as HCO3-and H2 PO42-have negative effect on the arsenic removal.