沸石改性及其在硫酸锌溶液中的脱氟性能
Zeolite modified and de-fluorination performance in zinc sulfate solution
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摘要: 采用硝酸镧溶液浸泡负载元素镧的方法对天然沸石进行改性,通过静态吸附法研究改性沸石脱除硫酸锌模拟溶液的脱氟性能,考察改性沸石用量、pH值、吸附时间、吸附温度4个因素对改性沸石除氟性能的影响;并利用EDX、BET等分析手段对沸石改性前后的成分、形貌及微观结构进行表征。结果表明:当改性沸石用量为7.5 g/L,吸附时间25 min,反应温度为40 ℃,pH=4时改性膨润土的除氟量最大,氟离子浓度由100 mg/L降至45.56 mg/L,符合工业生产中所规定的小于50 mg/L;多种分析手段表明,改性后镧元素有效负载在沸石表面,同时沸石的层间距和比表面积都有所增加,有利于提高沸石的除氟性能.Abstract: Zeolite was used as the adsorbent and modified with lanthanum nitrate. An experimental study of the treatment of fluoride in zinc sulfate solution by modified zeolite was carried out. The influences of addition amount of modified bentonite,adsorption time,temperature and pH on the amount removal of fluoride were introduced. Energy dispersive X-ray analysis(EDX)and specific surface area(BET)were used to characterize the adsorbent before and after modified. The results show that the concentration of fluorine can be dropped from 100 mg/L to 45.56 mg/L,which conform to the provisions in the industrial production of less than 50 mg/L,when modified bentonite being added in an amount of 7.5 g/L,adsorption time being 25 min,temperature of 40 ℃ and pH=4. Variety of analytical tools show that,the lanthanum element payload on the surface of zeolite after the modification,and the layer spacing of zeolite and specific surface area are increased at the same time. I improves the fluoride removal performance of zeolite greatly.