粉煤灰合成Na-X沸石去除废水中镍离子的研究

粉煤灰通过碱熔融 水热法合成了Na-X型沸石，研究了Na-X型沸石的用量、吸附时间、溶液pH值、初始镍离子浓度和温度对废水中镍离子去除效果的影响。结果表明，Na-X型粉煤灰沸石对镍离子的去除性能与化学原料合成的13X相当，明显优于粉煤灰。在20℃，pH值为6，沸石用量10g/L，吸附15min时，对初始浓度为20mg/L~150mg/L的镍离子去除率均可达90%以上。镍离子的吸附过程符合Langmiur吸附等温方程式，其单层吸附量为11.2×10^-3。粉煤灰沸石重复使用5次，对废水中镍离子的去除率仍高达95%，再生性能良好。

Removal of Ni~(2+) from waste water by Na-X zeolite synthesized from coal fly ash

Na-X zeolite (ZFA) was successfully synthesized from coal fly ash (CFA) through NaOH fusion and hydrothermal treatments and used to remove Ni~(2+) in waster water. To obtain the optimum conditions of Ni~(2+) sorption on the ZFA, the influence of operation conditions like solution pH value, adsorbent dose, contact time, Ni~(2+) ion concentration and adsorption temperature was investigated. The results showed that the ZFA obtained in this work is comparable with the 13X zeolites synthesized from chemicals in the efficiency of Ni~(2+) removal from wastewater. More than 90% of Ni~(2+) could be removed by ZFA from the waste water with initial Ni~(2+) concentration of 20mg/L～150mg/L at 20℃, solution pH value of 6, sorbent dose of 10g/L, and contact time of 15min. The adsorption of Ni~(2+) on the ZFA fits the Langmuir isotherm well;its monolayer adsorption capacity reaches 11.2×10~(-3) at 20℃. ZFA exhibits good regenerability and its removal efficiency for Ni~(2+)does not decrease within five recycles.