The Ability Of Selenium(?) Adsorption From Aqueous Solution By Zeolite Synthesized From Fly Ash

This study used high-and low-calcium fly ash to get synthesized zeolites via a alkaline fusion hydrothermal method.The synthesized zeolites were characterized using X-ray diffraction(XRD),a scanning electron microscope(SEM),and investigated their efficiency of removing selenium(Se(IV))from an aqueous solution.The influence of pH,adsorbent dosage,initial Se(IV)concentration,contact time,temperature and coexisting anions was also investigated by batch experiments.The performances of two kinds of synthesized zeolites to remove Se(?)were analyzed,the regeneration performance of zeolite was also discussedThe results showed that the high calcium fly ash synthesized zeolite mainly comprised an unnamed zeolite(Na6[AlSiO4]6·4H2O),and the low calcium fly ash synthesized zeolite mainly comprised a faujasite-type zeolite,zeolite p and a kind of unnamed zeolite(NaO·Al2O3·3SiO2·6H2O).Compared with the fly ash,the specific surface area of the two kinds of synthesized zeolite increased greatly.The adsorption process of selenium(IV)showed the characteristics of fast adsorption,reaction time 360min to reach equilibrium,and the adsorption process followed the pseudo-first-order model.The removal efficiency of selenium(IV)was affected greatly by pH value,it is a great adsorption effect of selenium(IV)when pH is below 2.0,the removal efficiency of selenium(?)decreased with the increase of initial concentration,with the increase of the dosage increased first and then decreased.PO43-significantly affected Se(?)removal.The adsorption capacity of high calcium zeolite on the adsorption of Se(IV)was 6.02 mg/g,and the adsorption capacity of low calcium zeolite was 5.36 mg/g.Adsorption isotherm data is accord with Langmuir model and Freundlich model,so it is more certain that the adsorption of Se(IV)on synthesized zeolite is a preferential adsorption proeess.Zeolite regeneration experiments showed that the regenerated zeolite still had a high removal efficiency of Se(IV).Therefore,in order to reduce the cost of pollutant treatment,the saturated synthesized zeolite can be recycled for recycling usage.Using fly ash to synthesize zeolite not only can remove selenium(IV)in wastewater effectively,but also realize the utilization of fly ash.