Preparation Of Alginate And Its Porous Film Of Graphene Oxide And Study On Its Adsorption Properties Of Methylene Blue

With the rapid development of human society,the consumption of dyes in textile,printing,dyeing,papermaking and other industries is increasing continuously.The indiscriminate emission of dye-containing wastewater can not only affect the ecosystem,but also threaten the human health.Therefore,the pretreatment of dye-containing wastewater before emission is highly necessary.Among all the wastewater treatment methods,the adsorption method has become the most widely used and effective one due to its simple operation,high efficiency,and the ability to remove macromolecular contamination on a large scale.In this paper,acidified sodium alginate(ASA)was obtained by acidizing of sodium alginate.The morphology and physicochemical properties of ASA were characterized by different techniques,and the influence of external conditions on the MB adsorption performance of ASA was studied and analyzed through systematic experiments.By fitting the adsorption data using the Langmuir model,the maximum adsorption capacity(1552.3mg/g at 298 K)could be obtained.Meanwhile,the thermodynamic investigation indicated that the adsorption was a spontaneous,exothermic process.The graphene oxide(GO)was prepared by improved Hummers oxidation approach.The morphology,crystal structure and thermostability were characterized by different measurements.Calcium alginate membrane(CAM)and calcium alginate/graphene oxide membrane(CA/GOM)were prepared by a novel method of blending and vacuum freeze drying.And their physicochemical properties were measured by various characterization methods.The adsorption performances under different conditions were determined by systemic adsorption experiments,and at the same time the adsorption kinetic data were evaluated by different adsorption models.Then the adsorption equilibrium data of CAM and CA/GOM were calculated by Langmuir and Freundlich models,and the result revealed that these two membranes possess relatively large theoretical adsorption capacity.Thermodynamics studies indicated that the adsorption behavior of CAM and CA/GOM on MB were all spontaneous exothermic process.After several cycles of adsorption experiments,CAM and CA/GOM could still maintain relative high adsorption capacity,indicating that these two membranes were adsorbents with excellent adsorption capacity and good repeatability.