| D301R is one type of styrene macroporous anion exchange resin, it can achieve reuse of Cr （VI） and water in the treatment, which is a clean production technology. However, during the operation the problem of resin "pollution" greatly hinder the promotion of the ion exchange method in the treatment of wastewater containing hexavalent chromium. Therefore, the pollution of the resin is the most difficult problem in ion-exchange treatment for wastewater containing chromium. Based on the research in and abroad, further studied D301R resin treatment system for electroplating wastewater with hexavalent chromium, tracked the pollution course of the resin, and did some research on the resurrection after resin polluted. The conclusions are summarized as followed.Part I’Research on treatment process of electroplating wastewater containing chromium（1） Experiments showed that Cr （Ⅵ） could be optimally adsorbed at pH=2-4, the rinse wastewater used was in the range, which is helpful to the adsorption of Cr （Ⅵ）. With the water temperature increasing, the exchange capacity increased. Cr （Ⅵ） absorbed on the resin could be eluted by the5%NaOH-5%NaCI solution, and the percentage of elution was up to98.02%initially.（2） The results of dynamics showed the adsorption rate of D301R resin for Cr （VI） was mainly controlled by liquid film diffusion and chemical reaction process, the reaction followed the Freundlich model, the fitting line was Qc=16.59Ce （?）, n equaled to3.476. between2and10. which explained D301R resin was fit for electroplating wastewater containing hexavalent chromium.（3） Adsorption thermodynamics parameters for Cr （Ⅵ） were determined.△H298K=2.88kJ/mol,△G298k=-3.78kJ/mol, indicating that the process is a spontaneous endothermic reaction, higher temperature is conducive to the adsorption for chromium. Part Ⅱ The mechanism of resin contamination and the resurrection methods（1） The experimental results showed that the resin was mainly contaminated by metals, organic polluted slightly. From aspects of metal. some metal hydroxides form particles "embeddeing" in the gap channel wall to cover up a part of the exchange sites, this parts of metal is easy to remove; another decline reason of the exchange capacity is a coordination with the nitrogen atom, forming alaceholder", they have strong adhesion with resin and difficult to dispose. From the point of view of organic pollution, on the one hand, part of the organic absorb the inner surface of resin under van der Waals" force.causes"’blocking". covering some exchange sites:some organics and metal ion occupy or cover the exchange sites as molecules.（2）The orthogonal optimization experiment about factors affecting resurrection process showed that the optimal conditions of resurrection are20%wt hydrochloric acid. soaking for24hours. soaking temperature of333K and20%wt of alcohol. Under this condition, the resin resurrection rate can reached76.46percent.（3） Among the new resin, resin, resurrected before and after, by the Characterization methods such as adsorption capacity. TEM morphological characterization, the BET surface area and poresize distribution. EDX photoelectron spectroscopy and IR infrared spectroscopy. results showed that the absorbing capacity. surface area, poresize of the resin resurrected after treatment increased, the metalic amount of the decreased, the infrared spectrum showed the peak amplitude migration of N-H blending vibration reduced after resurrection. the effect of resurrection was good. |
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