Preparation Of Polypropylene Ion Exchange Membrane And Its Application In Metal Ion Wastewater Treatment

Electroplating wastewater pollution is one of the main industrial pollution at present,As to all the methods of concentration and separation heavy metal ions,using membrane materials for electrodialysis separation is pretty economical and effective.This paper introduces a new type lab homemade polypropylene homogeneous ion exchange membrane,And then,we do some related tests to the membrane,At last,we use the membrane to make the electrodialysis device machine run.At the same time,we make some comparison on the membrane what we made and the heterogeneous membrane.As the data shows that this experiment is utility,and we could Accumulate experience for farther study.Firstly,with the help of initiator ammonium persulfate,benzoyl peroxide(BPO)and crosslinker N,N’-methylene diacrylamide,we use two monomers(M APT AC and acrylic acid)to graft onto polypropylene fabric,Simultaneously,using two monomers to do solution polymerization,after the grafted polypropylene fabric has been cleaned,we need to coate two polyer(M APT AC and acrylic acid)to the surface of the two grafted polypropylene,So that the two kinds of polypropylene(PP)homogenous ion-exchange membranes have been made.Secondly,we do some tests about two membrane,such as scanning electron microscopy、infrared spectroscopy and thermogravimetric analysis,we also discuss some factors on graft ratio,e.g:Initiator and Crosslinker,Simultaneously,the relationship between the two waterproofing properties and water content,waterproofing properties,electrical conductivity,ion exchange capacity and tensile properties was discussed.Finally,two kinds of membranes were placed in the electrodialysis device to concentrate and purify the simulated electroplating wastewater.The conclusions are as follows:1.The optimal monomer proportion of MAPTAC and acrylic acid was about 35%,and the corresponding graft rates were 75%and 81%,respectively.2.Under the same conditions,with the action of a single initiator(ammonium persulfate or BPO),the grafting rate of MAPTAC was 60%and 63%and the grafting rate of acrylic acid was 70%and 65%.under the action of double initiators.The grafting rate of MAPTAC and acrylic acid was 73%and 85%,therefore,the double initiators can help increase the graft rate of polypropylene fabric.3.Under the condition of keeping the monomer concentration at 35%and initiator content at 3.2%,with the increase of crosslinking agent concentration,the grafting of MAPTAC and acrylic acid increased firstly and then decreased,and the optimal proportion of crosslinking agent in MAPTAC was about 5.5%,while the optimal proportion of acrylic acid was about 6.1%.4.After grafting,two kinds of membrane surface resistance become significantly lower,blank sample is 8*109Ω。,after grafting,it raised to 3*108Ω2 and and anthoer one is 1.7*108Ω,at the same time,heterogeneous membranei is 4*108Ω,resistance is decreased obviously after grafting,experiments show that if the grafting monomer content increased,the surface will also reduce resistance.5.The two waterproofing technologies(waterproofing with water-proofing agent and waterproofing with hexahydroxyl resin)are characterized by that hexahydroxyl resin will react with hydrophilic groups on the membrane surface to reduce the ion exchange capacity,but the waterproofing performance is good.Waterproofing agent adheres to the membrane surface after heating,which is characterized by high ion exchange capacity but poor waterproof performance and durability.6.The mechanical properties and hydrophilicity of the ion exchange membrane prepared by grafting and coating of the two monomers are better than that of polypropylene fabric.The water content of the membrane material prepared by the waterproof is higher than that of the film water content of hexahydroxy resin.7.In the electrodialysis experiment comparison between the self-made homogeneous film and heterogeneous film,the concentration of copper ion in the concentrated chamber of homogeneous film was 330ppm,while that in the concentrated chamber of heterogeneous film was 240ppm.The electrodialysis effect of self-made homogeneous membrane is better than that of heterogeneous membrane...