Research On Preparation,Properties And Application Of Micro-mesoporous Diatomite-zeolite Adsorbent Composites

Today,environmental problems are increasingly prominent,environmental protection has become the theme of current society.Water shortage is very serious in our country,re-use of waste water has become the consensus of the people.The zeolite has great potential application value in the water treatment the field,because of its crystal structure,regular pore size distribution,adjustable surface properties and adsorption of various substances.The diatomite is a kind of porous material which has unique surface structure and good adsorption properties,it has large pore volume,good stability,abundant resources,cheapness,so it has been made as adsorbent used in various industrial waste water treatment process.But they also have some disadvantages,the diatomite's aperture is too large,and its adsorption efficiency is not very high;the zeolite is prone to agglomerate,inaddition,it has high cost,and difficult to recycle.Therefore,it has great value to study how to unite the zeolite and diatomite to compose to micro-mesoporous functional adsorption material and apply it to the field of water treatment.The main results are as follows:(1)Using pretreatment method(adding CTAB in modified precursor fluids)and postprocessing method(adding NaOH solution to etching)to introduce micromesoporous into diatomite and zeolite composite adsorption material,research and compare adsorption properties of the micro mesoporous composite adsorbent.The results show that the proportion of macroporous/ mesoporous/ microporous is reasonable and uniform when the micro-mesoporous diatomite-zeolite composite adsorbent prepared by pretreatment method(precursor solution n(CTAB): n(TEOS)=0.20),it has multi-level hierarchical pore which can fully capture and retention model organic pollutants,especially has a very good adsorption effect on phenols(phenol)model organic pollutants.(2)Using optimized method for preparation of micro-mesoporous diatomite-zeolite adsorption material to try phenolic model organic pollutants adsorption experiment,and conduct a series of analysis on the adsorption conditions and adsorption effect.The results show that the in pH 6-7(most reasonable for practical application),phenolic organic pollutants in the solution is conducive to the molecular form,which is beneficial to the adsorption of the micro-mesoporous diatomite-zeolite composite material with rich multi-channel structure,and the adsorption effect is very remarkable,for phenolic organic pollutants(phenol,benzene two phenol,Resorcinol,hydroquinone)removal rate was above 90%.(3)Study on how to put the micro-mesoporous diatomite-zeolite composite material and electrochemical methods together to form a combined technology which contains the air stripping method-Electrochemical Oxidation-optimized micro-mesoporous diatomite-zeolite composite material adsorption technique,and apply it to waste water treatment.The results show that,when air velocity is140ml/min,the stripping temperature is 55 C,the current density is 30mA/cm2,and the adsorption material is the best micro-mesoporous diatomite-zeolite composite adsorption material,this combined technology has the best removal effect on phenol model organic pollutants,which above 98%,the adsorption effect was better than that of the simple using of micro-mesoporous diatomite-zeolite composite material.