Preparation And Properties Of Chitosan Composite Film And Nano Composite Fiber Felt

Cr（Ⅵ） is a toxic heavy metal ions, as industrial development and the use of chromium,the large number of chromium-containing industrial wastewater discharged into theenvironment, causing serious ecological environment and human health threat. The way todeal with heavy metal ions is much, such as chemical precipitation, ion exchange andelectrolytic method, but those methods will produce large amounts of sludge and causessecondary pollution, the application is limited, membrane adsorption method because of easyoperation, low cost advantage has recently become research hot spot and the important topic.Using film as the adsorbent purification industrial waste and recycling heavy metal ion is avery potential and value choice.Chitosan as a non-toxic, environmentally friendly membrane material in recent years byan increasing number of researchers concern, but the chitosan film made by pure chitosanexisted some shortage when adsorption heavy metal ions in water. Therefore looking for amodified chitosan film, its become a research hotspot in the water adsorption performance.In this study, based on some of the shortcomings of chitosan membrane adsorption ofheavy metal ions in water, use of rare earth ions modified chitosan to improve theperformance of the adsorption of heavy metal ions chromium.Preparation of chitosan/PVA/cerium oxide composite film, and test related machineryand adsorption performance, and found that the modified CeO₂can be uniformly dispersed inthe composite film, the composite film of improved thermal stability with increasing of CeO₂breaking strength and elongation at break increases the swelling ratio decreased compared topure chitosan film, breaking strength can be increased by47.4%, the maximum swelling ratiodecreased53.9%.Adsorption performance of the composite membranes on the concentration of chromiumions in the water, depending on the time, the initial concentration of chromium ions, pH,addition amount, the study shows that when the pH=4, Cr（VI） concentration is20mg/L, thetime up to8hours. The composite film adsorption reached equilibrium adsorption amount of38.5mg/g, the adsorption rate reached90%.Based on the excellent mechanical properties and adsorption properties of chitosancomposite film, preparation of chitosan/PVA/cerium nitrate composite nanofiber mat tostudy the surface morphology of the composite nanofiber mat, and found a concentration of2%chitosan solution, The solution of polyvinyl alcohol concentration of10%, and both theblend ratio is3:7, then add3%of the mass fraction of cerium nitrate hexahydrate, and spun out of the surface morphology of the electrostatic spinning fiber membrane.Depending on the time, the initial concentration of chromium ions, pH, addition amount,the study of the adsorption properties of the chitosan composite nanofiber mats, when thesolution pH of4, have the best adsorption; after the adsorption time of8h,the adsorption havethe equilibrium. The equilibrium adsorption amount of28.14mg/g; chromium ion removalrate reached88.1%.Developed chitosan/PVA/cerium nitrate composite nano-fiber mat for wastewatertreatment, in particular, provides a new approach to the treatment of wastewater containingheavy metal ions.