| In this paper, the studies were focused on preparation of the catalytic sorbent in the oxidation processes and it was regenerated the by high temperature gas catalytic oxidation method, and the actual production wastewater of the ink industry was disposed by this sorbent. We were making basic applied research that wastewater was disposed by the adsorption-regeneration of high temperature gas catalytic oxidation method. The main research contents and conclusions were as follows:1.That the Sepiolite was modified was researched.Selecting the diameter of 0.25 to 0.37 mm Sepiolite, Sepiolite was modified by three methods (thermal modification, acid modification, acid/thermal modification), and the acid/thermal modification improved the adsorption capacity that was the best in the all,and the equilibrium adsorption capacity of acid/thermal modification Sepiolite was more than 56.41mg/g to Sepiolite's (44.41mg/g).2.Metal oxid/thermal modified Sepiolite composite sorbents were prepared.The regeneration rate of Co-Fe-Sepiolite sorbent was 67.40% and higher than the regeneration rate of Al2O3,ZnO, Fe2O3, Cr2O3, CO2O3,CuO,MnO2 that was single loaded in the thermal modified Sepiolite about 29.40%,26.88%,17.61%,10.00%, 11.35%,21.12% and 31.30%. Using Response Surface Methodology to optimize preparation of Co-Fe-Sepiolite sorbent and obtain the optimal process parameters:n Fe (NO3)3:nCo(NO3)3 was 2.0:1,the mass of metal oxid/Sepiolite ratio was 0.5:10 and calcination temperature was 610℃,and then the predicted maximum regeneration rate of Co-Fe-Sepiolite sorbent was 80.26% and the actual maximum regeneration rate was 79.93%.Consequently, the model was accurate in this experiment.3.Adsorption behavior of crystal violet in Co-Fe-Sepiolite sorbent was studied. In this studied, in the range of temperature and concentration, the adsorption isotherms were fitted accurately by the Langmuir equation and this adsorption was an endothermic process. Kinetics studied showed that crystal violet was adsorbed by Co-Fe-Sepiolite sorbent fittes both the Lagergren rate equation and the Grank that was an internal diffusion model in this process. Using Response Surface Methodology to optimize the process that crystal violet was adsorbed by Co-Fe-Sepiolite sorbent and obtain the optimal process parameters:h:d was 3.56:1,wastewater concentration was 0.96 mg/L, wastewater flow rate was 4.35BV, and then the predicted maximum adsorption capacity of Co-Fe-Sepiolite sorbent was 32.90mg/g and the actual maximum adsorption capacity of was 33.57mg/g. Consequently, the model was accurate in this experiment.4. That Co-Fe-Sepiolite was regenerated in the high temperature gas catalytic oxidation process were studied. Crystal violet was adsorption object, the regeneration conditions effected on the high temperature gas catalytic oxidation process was studied, and the results showed that:(1)The higher the regeneration temperature, the interspace rate and the regeneration time increase, the regeneration rate of sorbent would be higher, and the optimal process parameters:the regeneration temperature was 600℃to 700℃,the interspace rate was 150min-1,and the regeneration time was 10min. (2) When the number of regeneration increased, regeneration rate decreased slightly, but the regeneration rate of Co-Fe-Sepiolite sorbent still could reach 72% after 40 regeneration times. Consequently, the regeneration performance was good.5.According to use many detectable characterization methods to analyze the process that crystal violet was adsorbed by Co-Fe-Sepiolite sorbent, and the results showed that:the adsorption process had electrostatic adsorption, surface adsorption, pore adsorption, and several mechanisms exist and synergy.6. Preliminary studied that the actual production wastewater of the ink industry was disposed by Co-Fe-Sepiolite adsorbent. When that the flow rate of wastewater was 4.35BV through the adsorption column that its h:d was 3.56:1,the color of treated wastewater was 0 to 5,CODCr was 1064mg/g to 1098 mg/g. When the regeneration temperature is 660℃,space velocity 150min-1,regeneration time of 10 min, and the regeneration rate was 81.26%. Co-Fe-Sepiolite adsorbent was 10 regeneration times, and regeneration rate decreased slightly and the change rate was about 2.5% every time.
|
PDF Full Text Request