Regeneration Of Adsorbent By Catalytic Oxidation And Its Application In The Treatment Of Dye Wastewater

In this paper, the method of catalytic oxidation is introduced to regenerate resin adsorbent. The application basic research about adsorption-catalytic oxidation to treatment dye wastewater is studied. The main research content and results are as follows:1. The adsorption behavior of reactive deep blue K-R on D301 resin is studied. A well fitted Freundlich equation is obtained for the adsorption isotherm within the observed temperature and concentration range, indicating an endothermic and a favorable adsorption. The results of the enthalpy of adsorption, free energy, and entropy of adsorption indicate that : the positive value ofâ–³H shows an endothermic process, and the negative value ofâ–³G shows the spontaneous nature of the adsorption process, and the positive value ofâ–³S indicates the increased randomness at the solid/solution interface during the adsorption process. The kinetic study shows that the adsorption process is under the control of intra-particle diffusion and other diffusions simultaneously. The dynamic adsorption property of reactive deep blue K-R on D301 resin is researched. The results are as follows: the increase of flow rate leads to a worse breakthrough curve, the optimum flow rate is below 60 mL/h, the bed's ratio of highness to radius has a great effect on dynamic adsorption, the larger ratio of highness to radius has better adsorption effect than the smaller, the optimum ratio of highness to radius is about 5 within the observed range.2. D301 resin which adsorbed reactive deep blue K-R is regenerated by the method of H2O2-V2O5 catalytic oxidation. Effects of pH, temperature, reaction time, H2O2 dosage and V2O5 on regeneration efficiency are studied. The results indicate that: the regeneration efficiency of resin increases first and then decreases with the increase of pH value and reaction temperature; the regeneration efficiency increases first and then becomes slowness eventually with the increase of oxidation time, the H2O2 concentration and the V2O5 concentration. The optimum regenerative conditions are as following: pH is 3-4, the H2O2 concentration is 0.4 mL/mL, the V2O5 concentration is 1.6 mg/mL, and the regenerative time is 20 minutes under the normal atmospheric temperature. The relevant regeneration efficiency can stabilize more than 80%.3. The UV spectrum of homogenous catalytic oxidation reaction is studied. The results show that the characteristic peak of reactive deep blue K-R decreases with the increase of reaction time. It proves that the reactive deep blue K-R was decomposed in the process of reaction. The kinetics of homogenous catalytic oxidation reaction is described as second-order reaction.4. D301 resin which adsorbed reactive deep blue K-R is regenerated by the method of H2O2-MnO2 catalytic oxidation. The optimum regenerative conditions are as following: pH is 4, the H2O2 concentration is 0.2 mL/mL, the MnO2 concentration is 0.8 mg/mL, and the regenerative time is 30 minutes under the normal atmospheric temperature.5. The research with adsorbent including D301 resin, S-8 resin and polyamide to treat the industrial dye wastewater has been studied. The results indicate: the adsorption rate increases with the increase of pH; the CODCr value increases with the increase of time; at the equal time, the CODCr value increases with the increase of flow rate, the optimum flow rate is below 40 mL/h. The optimum regenerative conditions are as following: pH is 3, the H2O2 concentration is 0.2 mL/mL, the V2O5 concentration is 1.6 mg/mL, and the regenerative time is 30 minutes under the normal atmospheric temperature. With the increase of regeneration times, regeneration efficiency decreases, but more than 90%. The recycling property of resin is satisfactory.