| Dyes in Wastewaters are sometimes difficult to remove because of their inert properties.Another difficulty found during the removal of dyes is the low concentration of dye molecules in wastewater.Other conventional methods of removing dyes from wastewater such as adsorption with activated carbons,ion exchange and electrochemical techniques are either expensive or ineffective.Recently,adsorption techniques using chitosan composites have been designed to adsorb dyes as an alternative to conventional wastewater treatment processes.This paper uses PVA and TiO2 to form CS by sol-gel process.Depending on the adsorption capacity of methyl orange,the ratio of chitosan to PVA and TiO2 could be determined.Fourier transform infrared spectroscopy（FTIR）analysis showed that the adsorption films were composed by CS,PVA and TiO2 which are linked together by Hydrogen bond.From Scanning electron microscope（SEM）images,it was found that the adsorption films are neat and uniform.In this paper,the factors have been studied,such as film thickness,transmittance of light,volumetric swelling degree,resistance to acid,mechanical strength,lifespan and so on.And the different experimental conditions,the capacity of adsorption film,the initial concentration of methyl orange,pH,the reaction temperature and the reaction time,were also been investigated by single factor variable method.In the optimal reaction condition in which the maximum adsorption capacity of methyl orange is 6.6891 mg·g-1,that the capacity of adsorption is 0.03 g,the initial concentration of methyl orange is 10 mg·L-1,the value of pH is 3 to 5,the reaction temperature is 40 ℃,the reaction time is 2 hours.The Kinetic of CS/PVA/TiO2 films adsorbing methyl orange studies showed that the adsorption of methyl orange on CS/PVA/TiO2 was better defined by the pseudo-second order model.The Langmuir isotherm suggested monolayer coverage of methyl orange with an adsorption capacity of CS/PVA/TiO2. |
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