Preparation And Cooperative Adsorption Study Of Porous Bentonite

In this thesis, combined with the methods of single factor and orthogonal test, porousbentonite was prepared semidry method in a using bentonite, organic modified bentonite withcetyl trimethyl ammonium bromide and ordinary portland cement as raw material, packingand matrix, respectively. Moreover, the coordination adsorption effect of porous organicbentonite on organic pollutants and heavy metal ions in mixed solution were investigated.The structures of organic bentonite were characterized with XRD, FTIR, TGA and BET.It was showing that the interlayer spacing increased from1.305nm to1.992nm. The bestprocedure conditions were as following:3.2g organic bentonite (particle size o f200~300mesh),0.34g aluminum ash dispersed into3.6mL hydrochloric acid solution (the concentrate-ion of HCl is0.16mol/L) and mixture for25min. The porous organic bentonite was obtainedwith high specific surface area about38.22m2/g.The adsorptions of porous bentonite toward organic pollutants and metal ions wereanalysed with ultraviolet spectrophotometer and atomic absorption spectrophotometer. Theresults showed that the optimum adsorptive conditions of porous bentonite were as following:the adsorption temperature for45℃, pH from6to10, the mixed solution concentration for0.3g/40ml and adsorptive oscillation time for45min, respectively; the maximum removalrates toward p-nitrophenol and Pb2＋were89.76%and97.08%. The organic pollutants andheavy metal ions could be adsorbed by porous bentonite in adsorption mixture simultaneous-ly.The further study showed that the adsorption of porous bentonite towared Pb2+was notaffected by p-nitrophenol，but the adsorption towared p-nitrophenol increased with theincreasing molar ratio of p-nitrophenol and Pb2+;The research revealed that the adsorptionmodels were represented well by Langmuir and Freundlich sorption isotherm; the formershowed a better fitting degree.