Synthesis Of Zeolite-A From Coal Fly Ash And Its Application In Tannery Wastewater Treatment

By using coal fly ash as main material, the alkali fusion-hydrothermal synthesis method was adopted to prepare zeolite-A and apply it to tannery wastewater treatment in this paper. The structures of coal fly ash and zeolite-A were characterized by the SEM, XRD and XRF. We have chosen Ammonia-Nitrogen, Totle-Cr and COD as indicators and have studied the either optimum condition of two reactions-zeolite-A synthesis and the tannery wastewater treatment. The results indicate: We can get zeolite-A by the alkali fusion-hydrothermal method. Variation of gelling-time and solid/liquid play a large part in deciding the type and the characteristic of zeolite-A.The best quality of zeolite-A could be synthesized under the condition of solid/liquid 1:5 and gelling-time 24h, among which zeolite-A accounts for 69%. Under different conditions, zeolite-A always has a certain removal rate to Ammonia-Nitrogen, Total-Cr and COD. The highest removal rate are 99%, 72.86% and 37% respectively. The most remarkable parameters which have influence on the treatment effects for Ammonia-Nitrogen and Total-Cr are PH and temperature respectively. While the changing on parameters has less influence on the COD removal effect.This thesis consists of four chapters:Chapter 1, Introduction.Based on the summarization study about comprehensive utilization of coal fly ash, synthesizing method and application of artifical zeolite, character and teratment method of tannery wastewather, the research purpose, significance and detail plan for this thesis were given.Chapter 2, Synthesizing zeolite-A by using coal fly ash.In this chapter: Some zeolite-A were produced by the method of alkali fusion-hydrothermal. The effect on quality of products caused by changing solid/liquid and gelling-time was analysed and the optimum reaction conditions were proposed.Chapter 3, The test of zeolite-A on tannery wastewater treatment.Time, zeolite dosage, temperature and pH were chosen as some reaction parameters of experiment and the experiment was schemed by orthogonal way. 4 levels for each parameter(time 1h, 2h, 3h, 4h; zeolite dosage 0.5g/ml, 1g/ml, 2g/100ml, 4g/100ml;temperature 25℃, 30℃, 35℃, 40℃; pH 4, 7, 10, 12).Ammonia-Nitrogen, Totle-Cr and COD were considered as indicators. The experimental dates were analysed in statistical method and the optimum reaction condition was given at last.Chapter 4, Conclusion.The research results of this thesis were summarized and the further study was also suggested.