Modification Of Chitosan And Its Application In Wastewater Treatment

In this paper, a new type chitosan resin was prepared through inverse suspension crosslinking by formaldehyde and epichlorohydrin with chitosan as the raw material. The effect of the operating conditions on the properties of the resin was investigated. The structure of the resin was characterized by FTIR, SEM and TG The results revealed that the dosage of formaldehyde, epichlorohydrin and ethyl acetate affected the properties of the resin largely. A strong-acid-resistance, high-capacity, large-porosity chitosan resin was obtained under the optimum raction condition(chitosan/formaldehyde(g/mL) = 1:0.2, chitosan/epichlorohydrin(g/mL) = 1:0.4, chitosan solution/liquid paraffin(mL/mL) = 1:1.5 and chitosan/ethyl acetate(g/mL) = 1:0.2) in the experiment. The resin was a structre of micropore gel by SEM.The adsorbability, adsorption kinetics and adsorption thermodynamics to acid green 6B, direct fast yellow RL and disperse blue 56 by the new resin were studied in this paper. Its high-capacity and strong-acid-resistance were proved. In the acid condition, the adsorption efficiency to acide green 6B and direct fast yellow RL reached above 90%. Through the adsorption rate curve on adsorption behavior of the three dyes, they were all according with pseudo-secondary adsorption rate curve. The rate constant of adsorption increased with increasing temperature. Through the adsorption isotherm of the three dyes, acide green 6B and direct fast yellow RL were according with Langmuir equation, while disperse blue 56 was according with Freundlich equation. The adsorption behavior was an endothermic process. Entropy was increasing during the adsorption. So raising temperature was in favor of adsorption.