Research Of Magnetic Chitosan–graphene Oxide For Removing Organic Dye Of Wastewater

With the development of national economy, problems of water environment has caused widespread concern gradually.There exist massive toxic organic pollutants, acid-base materials and so on in the dyeing wastewater leading to the complicated components, stable properties, weak biodegradability.The phenomenon cause damage to normal repair process of water environment,demanding prompt solution.Absorption technique is the traditional method for the dispose of industrial wastewater,however,the conventional adsorbents have some shortcomings, such as low adsorption capacity, poor selectivity and secondary pollution.Synthesis of new-style provides planforms for the treatment of dyeing wastewater.In recent years,graphene-based composite materials,as a kind of absorption, shows excellent adsorption specialities because of huge specific surface area,great adsorption capacity.In this paper,the author prepared segregative magnetic chitosan-graphene oxide(MCGO) adsorbing acid dyes and basic dye respectively and assessed composite material’s adsorptive property and application condition.With the coupling interface between amino group and carboxy group,the magnetic chitosan was grafted with graphene oxide unorderedly,which contained abundant functional groups, great thermostability, magnetic particle Fe3O4 and could achieve rapid separatation.The adsorption saturation capacity for acid dye Methyl Blue(MB) of MCGO reached up to 66.43 mg/g,the time was thirty hours with three steps.The whole process conformed to the pseudo secondary dynamic adsorption model and Langmuir isothermal adsorption equation,indicating monomolecular adsorption.The adsorption saturation capacity could be promoted under the condition of acid media and hypothermia because of exothermal reaction. Adsorption behavior was assumed to happen via electrostatic, van der Waals interactions collectively. MCGO for MB was regenerated with Na OH as desorbing agent, which adsorbing capacity retaining 80% after five times cycling. The adsorption saturation capacity for basic dye Methylene Blue(MBL) of MCGO reached up to 104.5 mg/g,the time was four hours with two steps.This reaction conformed to the pseudo secondary dynamic adsorption model and Langmuir isothermal adsorption equation as the acid dyes’.Funcition groups distributed on the surface evenly and that the process was influenced by surface diffusion and particle internal diffusion. The adsorption saturation capacity could be promoted under the condition of basic media and hyperthermia because of endothermal reaction.Adsorption mechanism for MBL was similar to MB. MCGO for MBL was regenerated with HCl as desorbing agent, retaining 70% after five times cycling.Based on adsorption capacity and adsorption rate, MCGO is more suitable for basic dyes,while, stability of recycling for acid dyes is better.There are respective application conditions of MCGO for adsorbing various kinds of dyes.MCGO material as new adsorbents, possess tremendous potential in partical effluent disposal with extensive applicability and manipuility.