| Today,electroplating industry is so advanced that the amount of electroplating wastewater produced in our country is especially huge.The direct discharge of electroplating wastewater will cause serious pollution to the environment.Moreover,the electroplating wastewater contains large amounts of copper,iron,nickel,chromium and zinc and other heavy metals,the direct discharge of the waste of resources,if the resource recycling has great economic benefits.Therefore,this article through ion exchange resin adsorption process of electroplating wastewater,through theoretical and Experimental Research on a series of studies,selected four kinds of resin,and the effect and from the economic point of view,selecting optimal resin;at the same time the best conditions and the desorption of the resin static and dynamic adsorption process of heavy metals were determined;adsorpt:ion resin was studied;to study the changes in the amount of sludge before and after adsorption;the main research achievements are as follows:(1)The static maximum adsorption capacity of four kinds of resin,Cu2+,Ni2+ and Cr6+,on three kinds of heavy metals,D001732,D113 and D401,was studied.At a temperature of 25?,pH at about 3.5-4.5,the initial concentration is 300mg/L,the D113 and D401 resin for copper ion and nickel ion showed a strong adsorption ability.And D113 compared with D401 resin is more economical,the copper and nickel ion adsorption were as high as 220mg/g and 140mg/g,and the adsorption of chromium is 70mg/g.Therefore,this paper chooses the D113 adsorption resin to study.(2)On the experiment of mixed system,when the exclusion of Fe2+ interference solution,the adsorption capacity of D113 resin on the other three kinds of heavy metals has been greatly improved,preferentially selective sorption in the order of CU2+ prior to Ni2+ prior to Cr6+.(3)the isothermal adsorption model and kinetic process of D113 resin were studied,and the adsorption mechanism of three heavy metals,copper,nickel and chromium,was investigated.The results show that the diffusion and adsorption process of Cu2+ and Ni2+ on D113 resin belongs to the diffusion process of liquid film.Two kinds of resin adsorption process belongs to monolayer adsorption and in line with the Langmuir isotherm,and the adsorption of Cr6+ do not meet this model.(4)During the dynamic adsorption process,when the pH is 3.5,the HRT is 150min.the amount of resin is 50g,the removal rate of Cu2+ and Ni2+ reaches more than 90%,and the effluent concentration is 9.2mg/L and 19.2mg/L,and the removal rate ofCr6+ reached 69%.For the actual electroplating wastewater,at optimum conditions,the effluent concentration of Cu2+ and Ni2+ is 0.36mg/L and 0.47mg/L,has reached<GB21900-2008>electroplating wastewater discharge standards.For chrome,it also has 77%.Under dynamic desorption process,at ambient temperature,regulating the desorption agent(H2SO4)flow rate of 8mL/min,with a concentration of 1.0mol/L,he desorption rate of each metal ion can reach more than 95%.(5)After D113 resin adsorption pretreatment of electroplating wastewater,and then chemical precipitation,sludge can be reduced by more than 73%. |
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