Preparation And Defluoridation Properties Of Mg-Al-Zr Triple-Metal Cellulose Composites

Water plays an important role in both life activities and the ecological system.With the progress of social development and industrial level,however,the toxic and harmful substances,such as organic matter,heavy metal ion and nonmetallic ion,etc.,in the sewage and industrial wastewater had brought serious harm to the environment and human health.Thus to develop a new type of water purification technology is becoming imminent.With adopting the Mg/Al/Zr salts and cellulose as raw material,inorganic fluoride ion asthe targetmicro pollutants,two kinds of compound adsorption materialsare prepared by the method of hybrid modification in this paper.The as-prepared adsorption materials are characterized by a variety of technical meansandthe adsorption performances for the fluoride are studied systematically.The main contents and results are in the following:1.Mg-Al-Zr triple-metal composite was prepared by cheaper Mg/Al/Zr salts by a co-precipitation approach and the adsorption behavior of F-onto the Mg-Al-Zr triple-metal composite was investigated.The results show that the uncalcined composite exhibited the high fluoride adsorption capacity,had the higher BET surface area(200 m2/g)and the XRD patterns showed this uncalcined sample exhibited the typical bayerite Al(O H)3 and layered hydrotalcite-like diffraction peaks.Adsorption experiments further confirmed the composite displayed an excellent fluoride adsorption capacity even in a wide p H range of 3-10,and the Langmuirand Freundlich isotherms were fitted fluoride adsorption very well which suggesting the fluoride might be adsorbed on the surface of adsorbent in the mixed form of monolayer and multilayer.Coexisting anions C l-and NO3-had the negligible influence on the fluoride adsorption,while SO42-and PO43-dramatically inhibited the fluoride adsorption onto the adsorbent.Meanwhile,the adsorption material had excellent regeneration property and can still maintain good adsorption capacity,even after four times of recycling experiment.2.Cellulose-based Mg-Al-Zr triple-metal composite was obtained by cheaper Mg/Al/Zr salts and cellulose by a co-precipitation approach and the adsorption behavior of Fonto the cellulose-based Mg-Al-Zr triple-metal composite was investigated.The XRD patterns show this sample exhibited the typical bayerite Al(OH)3,layered hydrotalcite-like and cellulose diffraction peaks.Adsorption experiments further confirmed the composite displayed an excellent fluo ride adsorption capacity even in a wide p H range of 3-10,and the Freundlich isotherm was fitted fluoride adsorption very well which suggesting the fluoride might be adsorbed on the surface of adsorbent in form of multilayer.Coexisting anions C l-and NO3-had the negligible influence on the fluoride adsorption,while SO42-and PO43-dramatically inhibited the fluoride adsorption onto the adsorbent.The TG analysis of cellulose-based Mg-Al-Zr triple-metal composite to some extent improved the adsorption quantity of the Mg-Al-Zr triple-metal composite metal composites because of the dispersion effect of cellulose to Mg-Al-Zr three metal materials.