Insoluble Starch Xanthate Synthesis And Study Of Heavy Metal Wastewater Treatment

In recent years,with the development of society,the treatment of various industrial and sanitary wastewater and sewage has become one of the great concern focused issues.In this paper,it has studied the synthesizing of starch xanthate.Using starch bought from market as the material,epichlorohydrin as crosslinking agent,it has developed the agent which processing heavy metal waste water-insoluble starch xanthate(ISX),and done a lot of experiments optimizing the synthesis conditions of insoluble starch xanthate(ISX).The result shows that the best synthesis conditions for ISX are bellow:Starch:40g,sold by market;1%NaCl solution:60 mL;Epichlorohydrin:2.8mL;15%KOH solution:16mL;36%NaOH solution:50mL;CS₂:6mL;5.5%MgSO₄ solution:80mL.Stirring time is about 16 hours,the reaction temperature is ambient temperature. In such conditions,it can get a high degree of xanthate acidification to the Starch xanthate.MgSO₄ and Epichlorohydrin has no impacts to the degree of xanthate acidification,but they can enhance the degree of crosslink and the insolubility.Electrochemical analysis shows that there is an obvious absorption peak to copper ions,nickel ions,zinc ions,respectively near -0.230V,-0.150V,-1.122V.Processing copper ions,nickel ions and zinc ions wastewater:Take the option of appropriate amount of agent and pH value of solution,the residual concentration of the copper ions,nickel ions,zinc ions no longer change along the time over 30min,it shows that the reaction has finished,at this time the ion concentration in the residual solution is lower than the international emission standards,removal rate be above 97%.Among these,in the treatment of zinc-containing waste water,the remnants of zinc ions concentration is rising when the pH value reach 9.0,and the removal rate will be significantly reduced.The study shows that the exchange capacity of ISX is increasing with the increases of heavy metal ion concentration and sulfur content of ISX.Through the analysis of the ISX-Cu,ISX-Ni,ISX-Zn residues,we have found that the residues are very stable,extraction ratio is low,and there is no secondary pollution.Only under conditions of strong acid or strong alkaline conditions can metal ions be partly leached.Through references studies,chemical calculation to the solution,and the infrared spectrum analysis,we have analyzed the mechanism of removing heavy metal in the waste water by ISX.The results show that the removal of copper ions exist chemical adsorption and physical adsorption,while for nickel ions and zinc ions and other heavy metal ions only the role of physical adsorption.