Preparation And Adsorption Properties Of Chitosan Blend Membranes

The copper is recognized toxic heavy metal ions for environment and it will produce thousands tons of industrial wastewater contained copper every year with the development of industry and copper application broadly. The methods which have been used to remove heavy metal ions, such as chemical precipitation, ion-exchange, and electrolysis have been found to be limited, since they often involve amount of discharge sludge or secondary wastes which present treatment problems. The use of adsorption is becoming research hot spot and important subject in recent years due to its low cost and convenient operation. There in the use of membrane as adsorbent for heavy metal offers a potential alternative to existing methods for purification and recovery of these components from industrial wastewaters. CS/YC membrane usually used as food containers and table, medical material, water and alcohols separate membrane, this paper use the membrane as sorbent for heavy metal, find the membrane's color was changed after adsorption, the color was the same as the hydrated cation, this membrane has the potential of detect heavy metal ions rapidly, and study on the mechanism of Cu(II) onto the CS/YC membrane.The blend membrane of chitsan(CS)/modifier(YC) has been prepared. The structure morphology, the physical and chemical characteristics of the membranes were obtained by FT-IR, XRD and SEM. And the water absorption has beed tested. As a result, there were some interaction between YC and chitosan, which showed that blend of YC and chitsan was helpful to improve the adsorption capacity of the Cu( II).The effects on Cu( II )adsorption of pH, time, temperature, Cu( II) initial concentration, ionic strength, dosage were investigated by CS/YC membrane. The results show that pH=5-6 is the optimal condition for Cu(II) adsorption, the Cu( II )removal efficiency is 92.92%, strong acidic and alkaline solution are both unfavourably for adsorption. The adsorption process happened slow, adsorption capacity decreased with sorbent dosage increased, with ionic strength incresing first hoist and then falling, adsorption capacity increased with high initial concentration ,and decreased with solution temperature; coexisting canon of Co( II), Ni (II)have no effect on Cu( II )adsorption, which illustrated selectivity is good. Experiments data were analyzed by Langmuir model and Freundlich model, it noted Freundlich isotherm was better described the adsorption process. In addition, the process of desorption sorbent regeneration and recycle tests were also studied using 0.2% thiourea—0.02 M HC1 solution as regeneration agent, the results illustrated the desorption process complete quickly and efficiency, CS/YC membrane can be reused many times in recovery of Cu( II).Finally, the adsorption mechanism of Cu( II) onto the CS/YC membrane was investigated by XRD, SEM and analyzed according the performance of adsorption isotherm,it suggested that the main action role is physical adsorption and outer-sphere complex.