The Modified Chitosan for Dyeing Wastewater Treatment via Adsorption and Flocculation

Dyeing wastewater is characterized by high color, large amount of suspended solids and high chemical oxygen demand (COD), which has caused severe water pollution problems. In this experiment, carboxymethyl chitosan (CMC) was prepared by modifying the chitosan and used to treat dyeing wastewater. The properties of CMC such as adsorption and flocculation were analyzed. The effects of microwave power, pH of solution, dosage and stability on the removal efficiency of dyeing wastewater were successively investigated. The result shown that COD removal ratio, decolourization ratio and turbidity removal ratio of methylene blue treated by CMC were 66%, 84% and 78%, respectively. After the adsorption thermodynamics and adsorption kinetics analysis, the process for CMC adsorption dyeing was exothermic reaction and chemical adsorption. The adsorption process was the pseudo-second-order model and Freundlich isotherm. Therefore, the result had provided a promising adsorbent and flocculant for environmental applications.