Study On The Preparation And Adsorption Property Of β-Cyclodextrin Based Composites For Organic Pollutant

Dye is a kind of organic pollutant,which has certain toxicity and carcinogenic effect,but also causes reactions such as allergy,dermatitis or skin irritation.It is stable in water and difficult to be naturally degraded,and its color often brings visual discomfort.At present,the world’s annual market of more than 100,000 dyes,the annual output of more than 700,000tons.New environmentally friendly functional nanocomposites which can rapidly adsorb and remove dyes from water have attracted much attention from academia and industry.In this paper,C/SiO₂@β-CD and Fe₃O₄/SiO₂@β-CD composites were prepared by using Carbon spheres（C）and magnetic particles Fe₃O₄ as the matrix and by inorganic coating of silica and organic polymerization of cyclodextrin.The adsorption behavior of organic dye crystal violet（CV）in wastewater was studied,and the factors of the adsorption process were researched.The main research contents and conclusions are as follows:（1）Nano-carbon spheres were synthesized by means of high-temperature carbonization,which was coated with silica,and thenβ-cyclodextrin was polymerized on the surface of silica to prepare C/SiO₂@β-CD composite adsorbent.The transmission electron microscopy（TEM）and scanning electron microscopy（SEM）showed that the composite adsorbent presented a core-shell-shell structure with a size of 500-900nm.Compared with the carbon spheres,the adsorption performance of the adsorbent was improved byβ-CD and SiO₂.The adsorption process of the adsorbent for CV dyes conforms to the Langmuir adsorption model.The adsorbent showed good adsorption properties to the cationic dyes,methylene blue,Rhodamine B,bromophenol blue and anion dye Congo red.（2）A magnetic composite adsorbent material Fe₃O₄/SiO₂@β-CD was prepared by solvent heat method.The introduction of magnetic Fe₃O₄ leads to a more efficient operating process and higher recovery rate compared to C/SiO₂@β-CD adsorbent.FT-IR and SEM characterization showed that the magnetic material has a core-shell-shell structure and good dispersion.The material was used for the removal of cationic dye CV in dye wastewater.The experiment showed that high temperature and weak alkaline environment were favorable for the removal of CV dye.The material is a new kind of adsorbent with high recovery rate and can be used for many times.（3）The adsorptive behavior of dye CV on the fixed bed was investigated with C/SiO₂@β-CD as adsorbent,and the influence of several factors on the adsorption performance of the fixed bed system was investigated.The penetration curves of CV dye at different sorbent filling amount,CV dye flow rate and initial CV concentration were studied.The results express that the adsorption property is better with lower dye concentration and flow rate and higher sorbent filling quantity.Tomas model and Yoon-Nelson model were used to fit the comparative experiment,and the results showed that C/SiO₂@β-CD was a kind of adsorbent with stable structure and strong regeneration ability.