Preparation Of Gelatin/nano-Attapulgite Composite Film And Its Adsorption On Congo Red

With the improvement of people’s environmental awareness and the need to improve the ecological environment,the development of adsorption materials with low cost and no secondary pollution has become the research hotspot.In this paper,gelatin/nano-attapulgite composite membrane was prepared by adding attapulgite to gelatin based film.The morphology,structure and physical and chemical properties of the composite membrane were studied,which provided a theoretical basis for the feasibility of gelatin composite membrane in wastewater treatment.The adsorption mechanism was studied by using Congo red as azo dye wastewater model.The main research contents are as follows:Firstly,gelatin/nano-attapulgite composite film was prepared and its surface morphology,functional group structure,water solubility and mechanical properties were analyzed by SEM,FTIR,XRD,universal material testing machine and other instruments.And the influences of t the content of attapulgite on the properties of the composite film were investigated.Then the effect of attapulgite content on the adsorption behavior of Congo red on gelatin composite membrane was studied.The results show that the gelatin composite membrane has the strongest adsorption capacity when the mass ration of attapulgite and gelatin is 1:4.The adsorption capacity of the composite film was 355.99%higher than that of pure attapulgite.The results showed that the gelatin and attapulgite have synergistic effect on the adsorption of Congo red in the composite film.Finally,the effects of various adsorption factors(concentration of CR,pH,adsorption time and temperature)on the adsorption of the CR was studied.According to the adsorption data,△H<20kJ·mol-1、AS=0.26 kJ-mol-land △G<0(T=303K、313K、323K)were calculated.The results showed the adsorption process of gelatin/attapulgite composite film on Congo red was endothermic,and the adsorption was facilitated by increasing the temperature.Both physical adsorption and chemisorption exist during the adsorption process.The kinetic model and isothermal adsorption model were used to simulate the adsorption process of gelatin composite film for Congo red.The fitting results showed that the adsorption process of the prepared gelatin composite membrane on Congo red was consistent with the pseudo second-order kinetic model and Langmuir isothermal adsorption model.