The Preparation Of Al-Ti Pillared Bentonite And Its Adsorption Properties Of Arsenic

Bentonite is a kind of natural nanometer materials, which is widely used in thefields of waterproof, explosives, rubber, construction, paper and medicine,environmental protection and other fields due to its good swelling and dispersionsuspension, adhesion and plasticity resource-rich and ion-exchangeable andnon-toxic. With the expansion of the field of removing metal ions, thereforerequirements for the using of bentonite significantly improved to some detailsincluding low-input besides effective. So, using the way of pillaring to increase thespecific surface area and interlayer spacing to improve the adsorption properties ofbentonite, utilization and adsorption selectivity is necessary. As arsenic contaminatedwater has been part of the problem worldwide, it is full of reality and applicationprospects to remove arsenic using bentonite which is modified by pillaring that is onpurpose.The paper use the methods including montmorillonite content analysis,chemical analysis and XRD analysis to compare two kinds of bentonite which arefind in Mianyang in Sichuan and Yueyang in Hunan. The results show that Mianyangof which SiO2is main quartz and calcium, magnesium mainly in the presence ofsulfate. On the contrary SiO2of Yueyang soil is mainly in the presence ofMontmorillonite silicates which is good for pillaring.The analysis of blue absorptionpower also prove that Yueyang soil is more in keep with the command for pillaring.In this paper, using pulping-mixing-filtering-drying process the experimentalproduce acid-modified bentonite and organically modified bentonite. As can be seenin the XRD, characteristic peaks of bentonite of Acid-modified bentonite enhancedcompare with origin bentonite which indicates that crystal is changed and impuritiescleared effectively pore size increased. Characteristic peaks of CTMAB present in the XRD shows that CTMAB has inserted the bentonite cause increasing ofinterlayer spacing..The abilities in treating arsenic of which concentration is10mg/L of the threekinds of bentonite had been discussed. The adsorption of organically modified andoriginal bentonite which are not affected by not can reach35.3%and34.87%at themost. amounts, pH value, adsorption time and temperature. However, adsorption rateof acid-modified bentonite increases to47%by expanding interlayer spacing andspecific surface area.To improve the ability of adsorption in arsenic by expanding interlayer spacingduring inserting hydroxyl polymeric aluminum and titanium particles intobentonite.In this paper, According to suspended titration, Al pillared bentonite wasprepared by using the natural bentonite as starting materials. By selecting tetrabutyltitanate as precursor, Al-Ti pillared bentonite was prepared using the sol-gel methodand was characterized by XRD, FTIR, SEM. The abilities in treating arsenic of theoriginal bentonite and Al-Ti pillared Bentonite had been compared and the effects ofreaction conditions on arsenic adsorption such as the amounts of Al-Ti pillaredbentonite, pH value had been discussed. The results show that the adsorption ofarsenic by modified bentonite is better than that of the original bentonite and the pHvalue and the amounts of Al-Ti pillared bentonite will greatly influence theadsorption of arsenic. The adsorptive percentage reached99.54%at pH=4by0.5gL-1Al-Ti pillared bentonite during6h oscillating reactions under UV-irradiation.The concentration of treated waste water is0.0462mgL-1complied with nationalemission standards. The curves of isothermal adsorption of Al-Ti pillared bentonitein treating arsenic is in line with the equation of Langmuir.The way to calculate pillared angle of Al-Ti pillared bentonite has beendiscussed, and the pillared angle are87.48°and10.26°are been calculated outwhich meet the demand in the end. The desorption of Al-Ti-pillared bentonite full ofarsenic has been discussed, and found that the use of liquor reduction of nitric acidand sodium hydroxide sorbent law to improve desorption rate is not obvious.However, using of potassium dihydrogen phosphate for desorption can achieve thedesired results of which adsorption rate is97%when pH-6.