Preparation And Adsorption Properties Of Graphene Oxide Modified Sodium Alginate Composite Membrane

Dyeing wastewater treatment is one of the main problems in the textile industry,the dye in which will not only cause pollution to the environment,but also pose a serious threat to human health.At present,adsorption is a common method for wastewater treatment so that the study of adsorbents has become the focus of attention.As a new adsorbent,sodium alginate(SA)has the advantages of green regeneration,degradation and low cost.However,it has disadvantages of low efficiency,large usage when SA is used as an adsorbent alone.Whereas,although graphene oxide(GO)has a strong adsorption property,it has a poor recovery ability when used as an adsorbent.Therefore,it is a positive study to combine the two materials to obtain a new adsorbent with good adsorption performance and recyclability.In this project,two kinds of new adsorption materials were prepared by the method of surface modification with two kinds of SA membrane samples as the matrix and GO as the functional particles to characterized the structures and properties of them and to explore the adsorption of three cationic dyes.Firstly,to obtain a fiber membrane with uniform fineness and excellent mechanical properties,orthogonal design method was used to explore the effects of SA content,voltage,spinning flow rate and receiving distance on the properties of sodium alginate fiber membrane(SA/PVA).Secondly,with the GO produced by Hummers as function particles,graphene oxide modified sodium alginate fiber membrane(SA/PVA/GO)and GO modified freeze-drying sodium alginate porous membrane(SA/GO)were prepared to explore the effects of different adsorption conditions on the fuchsine,methyl orange and methylene blue dye respectively through single factor experiment,orthogonal experiment and response surface Box-Behnken experiment.Finally,SEM,TG,XRD and FTIR were used to characterize the properties of these two membrane samples before and after modification and adsorption.The results revealed that when preparing SA/PVA fiber membrane,the nano-fibers had small diameter and uniform fineness and the mechanical strength of the fiber membrane was the best when the concentration of SA and PVA were 2%,8%respectively,SA/PVA volume ratio was 4:6,spinning voltage was 15 k V,spinning flow was 0.08 ml /h,and the receiving distance was 12.5cm.Studying on the adsorption performance of SA/PVA/GO,the adsorption effect of fuchsine reached the best when the GO concentration was 2.5%,the initial concentration was 50 mg/L,the adsorption temperature was 45?,the adsorption time was 6 h,and the p H was 7.The adsorption effect of methyl orange dye reached the best when GO concentration was2.5%,initial concentration was 60 mg/L,adsorption temperature was 35?,adsorption time was 6 h and p H was 8.The adsorption effect of methylene blue dye reached the best when the GO concentration was 2.5%,the initial dye concentration was 60mg/L,the adsorption temperature was 50?,the adsorption time was 6 h,and the p H was 5.Studying on the adsorption performance of SA/GO,when the SA concentration was 3%and the GO contentration was 2.5%,2.5% and 1.5%,the adsorption effect of fuchsine,methyl orange and methylene blue arrived the best level respectively.Moreover,the adsorption effect of fuchsine reached the best when the initial concentration was 60mg/L,the adsorption time was 6 h and the p H was 6.The adsorption effect of methyl orange reached the best when the initial concentration was 50 mg/L,the adsorption time was 6 h and the p H was 8.The adsorption effect of methylene blue reached the best when the initial concentration was 60 mg/L,the adsorption time was 4 h and the p H was 5.