通过碱熔融—水热合成法,利用粉煤灰制备A型沸石,X射线衍射图谱显示产物晶型完整、结晶度高、产率达69%.产物对兰州市某制革厂废水进行批处理振荡正交实验,结果显示:A型沸石能很好地去除废水中的总Cr,去除效率高达99%;氨氮的去除率在70%左右,去除效果良好,对CODCr也有一定的去除作用.通过对实验数据的极差分析得出各污染物的最优反应条件:CODCr:反应温度35C,沸石投加量1 g/100 mL,振荡时间1 h,pH值为12;NH^4+:反应温度25℃,沸石投加量4 g/100 mL,振荡时间3 h,pH值为7;总Cr:反应温度30℃,沸石投加量0.5 g/100 mL,振荡时间2h,pH值为12.
Zeolite A was synthesized from coal fly ashes with the hydrothermal and alkaline method.X ray diffraction patterns showed that the product crystal owned an integrated shape and yielded up to 69%.Batches of oscillation orthogonal experiments were conducted on tannery wastewater in Lanzhou through this product and the results showed:zeolite A has a significant removal effect on total Cr and the removal rate could be as high as 99%.The removal rate of ammonia nitrogen is about 70%,indicating a good effect.CODcr can also be removed to certain extent.Optimal reaction parameters and conditions for the best removal rate can be determined by the analysis of the experimental data,which were respectively derived as,CODCr:reaction temperature 35℃,zeolite dosage 1 g/100 mL,oscillation time 1 h,pH value 12;NH4^+ reaction temperature 25℃,zeolite dosage 4 g/100 mL,oscillation time 3 h,pH value 7;Cr:reaction temperature 30℃,zeolite dosage 0.5 g/100 mL,2 h oscillation time,pH value 12.