微波辅助合成NaA型沸石及对铯离子的吸附研究

Microwave-assisted Synthesis of NaA Zeolite and Adsorption of Cesium Ion

针对放射性含铯废水,运用河南某电厂粉煤灰为原材料,对粉煤灰进行酸化、碱熔等预处理后,调整硅铝比、陈化时间和温度,运用微波辅助-水热合成法合成NaA型沸石分子筛,缩短其合成时间。其最优合成条件为:微波反应温度90℃、反应时间30 min、硅铝比为1.5、碱度2 mol·L-1、水热陈化温度为120℃、陈化时间8 h。对产物进行XRD、SEM等分析,其结晶良好。在pH>8的条件下,平衡吸附时间为120 min,对1 g·L-1的Cs2+溶液中的铯离子的去除率为98.45%,沸石的选择吸附性顺序为Cs2+>Sr2+>Al3+>Ca2+>Cu2。

In view of the radioactive cesium-containing wastewater,using the fly ash of a power plant in Henan province as the raw material,after the pre-treatment of the fly ash such as acidification and alkali melting,adjusting the silicon-aluminum ratio,aging time and temperature,NaA zeolite molecular sieve was synthesized by microwave-assisted hydrothermal synthesis method,reducing the synthesis time.The optimum synthesis conditions were determined as follows:microwave reaction temperature 90℃,reaction time 30 min;Si/Al ratio 1.5,alkalinity 2 mol·L-1,hydrothermal aging temperature 120℃,aging time 8 h.The products were analyzed by XRD,SEM and so on.Under the condition of pH>8,the equilibrium adsorption time was 120 min,the removal rate of cesium ion in 1 g·L-1 concentration of CS2+solution was 98.45%,and the order of zeolite selective adsorption was CS2+>Sr2+>Al3+>Ca2+>Cu2+.