Research On Amidoxime Modification Of Polyacrylonitrile Fiber And Its Application Of Wastewater

With the rapid development of social economy and science and technology,environmental pollution especially heavy metal waste water pollution has become a problem needed to resolve.Heavy metals caused great threat to the ecological environment,once in water or soil,it will be difficult to remove,leads to delayed development,all kinds of cancer,renal damage,and even death.Current treatment methods for heavy metals are mainly chemical precipitation,flocculation,chemical oxidation,reduction,electrochemical,ion exchange,adsorption,the adsorption is a kind of economic environment,easy and convenient to remove heavy metal ions in water,get the favour of scientific research workers.Polyacrylonitrile chelated fibre not only has the good performance of various heavy metal ions adsorption,but also can reuse,so that get widely research.In this paper,based on the previous studies,H2O2 was added to the amidoxime modification of polyacrylonitrile fiber.The effects of H2O2 concentration,hydroxylamine hydrochloride,reaction time,reaction temperature and pH were investigated.The conversion of the cyano and the adsorption capacity of the copper ions,the best experimental parameters were determined,and the modified fibers were characterized by infrared spectroscopy and scanning electron microscopy.The experimental results show that the addition of H2O2 can inhibit the hydrolysis of polyacrylonitrile fiber and promote the conversion of cyano group to amine oxime group.The modified fiber has a good adsorption capacity to copper ion.When the volume fraction of H2O2 was 5%,the reaction time was 4h,the reaction temperature was 80 C,n(PAN):n(NH2OH·HCl)=1:1 and the solution pH was 7.0,can be prepared cyano conversion rate is about 60%,and the adsorption amount of copper ions was 23.0mg/g of amidoxime polyacrylonitrile fibers.On the basis of the amidoxime polyacrylonitrile fiber,it is further crosslinked with epichlorohydrin,and the swelling and water absorption of the fiber after crosslinking are greatly reduced,and the heavy metal ions still have good adsorption capacity.The experimental results show that adding solvent volume 10%of epoxy chloropropane solution,reaction temperature was 110C,the reaction time was 12h,reaction pH was 13.0,modified fiber swelling in 0.5mol/L NaOH solution decreased from 400%to 130%,water absorbing capacity decreased from 7g/g to 2g/g,for copper ion adsorption quantity reach 22.3mg/g.Fiber modification conditions were determined in laboratory,entrust manufacturer to mass production,enlarge experiment for industrial wastewater,explores the practical application of additive amount of fiber,when the water flow and water pH influence on water quality,the reasonable parameters.Verify the crosslinking kai amine oximation polyacrylonitrile fiber is applied to the feasibility of the treatment of industrial wastewater.