Adsorption Of Acid-corroded Zeolite And Removal Of Organposphorous Pesticide In Water

Molecular sieves have been extensively used in various industrial relevance areas as adsorbent, catalyst support and heterogeneous catalyst. Recently, they play a potential significant role in environment protection to control noxious substances such as nitrosamines, and find their potential application in life science. Among these materials, special structure and innocuous property make zeolite an ideal material to remove nitrosamines in human stomach juice. Micropores in molecular sieves can significantly affect the adsorption capacity of adsorbents and induce strange and valuable phenomenon in the instantaneous adsorption process. Based on the novel adsorption ability of silicic materials, we wonder if these materials can perform well in remove the organphosphorous pesticide in surface water, which has caused many poisoning cases. We have done researches as follows:1. zeolite has been improved to be an effective material for adsorbing nitrosamines in both gas stream and solution. It might be possible that zeolite can be employed to remove NNN in human stomach juice to protect human health. While it is known that-Al-O-bond in zeolite is easily to be attacked by H+in acid solution, which leads to the dealumination and structure damage of zeolite. So in this work, a series of zeolite with different structure and Si/Al ratio were employed to study their structure variation after the acid leaching in the solution with the same pH value as that of gastric juice. Apart from the characterization with XRD, XRF, ICP and nitrogen adsorption-desorption methods, these samples are assessed to adsorb NNN in aqueous solution. In the last part,293-T cells were employed as probe to assess the NNN remove efficiency of zeolite in solution.2. Those porous materials with micropores perform quite strange in gas stream adsorption:Higher carrier gas flow rate result enhanced adsorption capacity, which is opposite to that of materials without micropores. The higher collision probability under higher gas flow rate together with the trap of micropores in channel wall conduce better adsorption performance. Apart from the known NPYR, phenol can also act as the target molecule to distinguish the contribution of micopores in instantaneous adsorption. So we wonder if this special phenomenon can provide an easy route to study the contribution of micropores in instantaneous adsorption through which we can characterize the micropore in material.3. Nowadays the organphosphorouse pesticide abuse has induced many cases of surface water contamination and poisoning. So in the last part of my work, we focus on the silicic materials and expect that an effective adsorbent can be found to remove those pesticides in water solution. Firstly we compared the actual adsorption performance of series of zeolites and mesoporous materials to figure out the key word in the process. And then based on the conclusion, we synthesized the more effective and low-cost silicic adsorbents. At last we will do research on the adsorption mechanism to synthesize novel materials in the future.