载镁活化天然沸石处理高氟水实验研究

为了提高沸石对氟的吸附能力,采用氯化镁对活化天然沸石进行改性,分析了除氟剂的性能,确定了除氟剂改性的最佳条件:10%氯化镁溶液,固液比1∶4,pH=7.0,室温以300 r/min的速度振荡改性3h。最佳除氟条件:pH=7.0,室温以300 r/min的速度搅拌反应1.5 h。吸附剂对F-的吸附过程符合Langmuir及Freundlich等温线方程,由D-R模型拟合可知,除氟剂对氟的吸附为物理吸附过程。在最佳反应条件下,水样中氟浓度由2 mg/L降低到0.78 mg/L,符合GB5949-2006《生活饮用水卫生标准》(≤1 mg/L)。

A STUDY OF FLUORIDE REMOVAL FROM WATER BY MgCl_2-ACTIVATED NATURAL ZEOLITE

In order to improve the adsorption capacity of fluoride on the zeolite,the activated natural zeolite was modified by MgCl2.Influences of several parameters such as pH,adsorbent dosage,and contact time on adsorption process have been analyzed in terms of batch experiments.The results of experiments showed that the optimum contact time,concentration of magnesium chloride solution,solid-to-liquid ratio,pH and oscillation rate for modification were 3 h,10%,1∶4,7.0 and 300 r/min,respectively.The optimum contact time,pH and oscillation rate for removal of fluoride by adsorbent were 1.5 h,7.0 and 300r/min,respectively.The results from the adsorption isotherm followed both Langmuir and Freundlich models,the D-R model fitting shows that adsorption of fluoride on fluoride agents is physical adsorption process.The magnesium chloride activated adsorbent was able to reduce fluoride in water sample from 2 to 0.78 mg/L,which meets the requirements of "Drinking Water Standards"(GB5949-2006)(≤1 mg/L).