β-cyclodextrin Immobilized Porous Material For Removing Phenol From Aqueous Solutions

The large amount of phenolic wastewater discharged from industrial processing, results in environmental pollution. β-cyclodextrin was often used to deal with wastewater containing phenol because of its unique cavity structure which could form host-guest inclusion compound with organic compound. So β-cyclodextrin Immobilized Porous materials as the economic efficiency of adsorbent were prepared for adsorption of phenol.Firstly,β-cyclodextrin was chemically modified and carboxymethyl β-cyclodextrin was prepared. The carboxyl groups were introduced onto β-cyclodextrin by carboxymethylation and the factors of affecting degree of substitution were studied. The material was characterized by FTIR and1H NMR. Four factors consisted of the amount of substance ratio of chloroacetic acid and β-CD, alkali concentration, reaction time and reaction temperature were studied, so as to achieve that carboxyl substitution degree of carboxymethyl β-cyclodextrin was controllable. Porous polystyrene materials were prepared by concentrated emulsion polymerization, and the surface was functionalized by amino groups on the basis of the chloromethylation and amination reaction. β-cyclodextrin was introduced into porous supporter according to the reaction with amino groups of porous polystyrene, more amino groups on the surface of porous polystyrene led to more P-cyclodextrin introduced into porous support. Therefore, ethanediamine, triethylene tetramine, polyethylene polyamine, and polyethyleneimine(MW=1800), which contained increasing amino groups in turn, modified porous polystyrene was designed to be the supporter, respectively. These materials were characterized by XPS, contact Angle, FTIR, BETand SEM. The impact of the dispersed phase volume fraction on the porous structure was discussed. The dispersed phase volume fraction at90%and polyethyleneimine modified porous polystyrene was selected as template.When the adsorbents were prepared, the factors consisted of the carboxyl substitution degree of β-cyclodextrin, the dispersed phase volume fraction of porous materials, contact time, initial concentration, temperature and PH on adsorption of phenol were studied. The optimum adsorption capacity was achieved at10℃and PH=5when the initial concentration was200mg/L and the volume fraction of the dispersed phase was90%, and also an adsorption equilibrium time of about35min was obtained. The maximum adsorption capacity of phenol was30.9mg/g. These immobilized materials present several advantages in wastewater treatment like high stability, strong mechanical intensity, recoverability, reutilization and sorption capacity increase.