New Type Of Micro Interface Energy Experimental Study Targeted Delivery Of Dye Wastewater Treatment

Dye wastewater, with high colourity, poor biodegradable and high toxicity, is one kind of refractory organic wastewater and the traditional biochemical treatment always can not get a desirable result. Currently, the treatment methods to dye wastewater that come into operation include biology method, chemical methods, physical-chemical technologies and so on. Chemical oxidation/reduction methods have a bright development prospect because of their high efficiency, stability and low cost. They present as the homogeneous catalytic wet oxidation and Zero-valent iron reduction/micro-electric method. According to the reaction phases, the reactions of them were both typical hetergeneous reaction.In the alternating magnetic field, magnetic materials would be heating sharply via hysteresis power loss and eddy current loss. Advancing organic wastewater treatment with high alternating magnetic field, applied watertreatment materials that can be induction heating, a reaction condition of high micro-reaction interface temperature will be realized, while the energy directly act on solid phase rather than aqueous phase. The micro-reaction condition will strengthen the degradation process of organic pollutant and lead to a lower aqueous temperature. In this research, a typical fixed bed reactor, integrated with alternating magnetic field producer and filled with sponge iron or the catalyst with a magnetic core, was used to treat the direct violet D-BL wastewater. Via this experiment, the effect to the degradation of dye wastewater of the micro-reaction condition of high solid/liquid interface temperature was observed and studied, so was the running and influence factors of water treatment under this novel micro interface energy transfer process. The results showed that:(1) Combining the fixed bed reactor filled with sponge iron and alternating magnetic field producer, the dye wastewater was treated and a reaction condition of high micro solid/liquid reaction interface temperature had been realized. The induction heat of the filled iron in the reactor was characterized and its mean temperature was deduced on the basic of energy balance between the filled iron and the water phase. Because of the limit of the coil height, in the experiment there was an optimal iron filling amount of25.00g for the established device. The mean temperature was positive correlate with particle size and was decreased with the flow rate increase. Because of the little differences in chemical composition, the mean temperature of sponge iron modified with different ways were slightly variable in the static bed, and were ordered as acid activated sponge iron, not activated sponge iron, copper activated sponge iron from higher to lower.(2)A comparative study showed that the novel technology had a better performance in the dye wastewater treatment than common fixed bed, due to the high interface temperature which tended to promote the degradation process. Hydraulic retard time (HRT) was an important parameter and would influence the result by changing the contact time and reaction temperature at the micro-reaction interface. Increase of the apparent temperature had a positive effect to the treatment. Activating with low concentration of Cu salt and acid were the appropriate modification method to sponge iron for this fixed bed reactor with induction heat system.(3)A copper impregnated SiO2catalyst with magnetic core of sponge iron (mCuO/SiO2) was prepared. Then a Wet Peroxide Oxidation with induction heat system (CWPOi) applied mCuO/SiO2as catalyst on direct violet D-BL wastewater was studied. The effect of the micro-reaction condition of the high interface temperature to the dye degradation was also investigated. The optimum condition of coating sponge iron:urea concentration19.2g/L, TEOS concentration0.20g/ml, aging at120℃for48h. The optimum condition of active metal loading:Cu(CH3COO)2solution as impregnation liquid, a1:1solid-liquid ratio(g/ml) and a calcination under400℃. The SEM and XRD analysis showed the catalyst prepared had the typical characteristics of SiO2and CuO and the cooper mass percent is0.34%. The iron merely played a role of magnetic core rather than reactant according to the analysis of element in effluent.(4)Compared with the traditional CWPO, the effluent temperature of column in CWPOi reactor was enhanced with the energy exchange between the magnetic core heating and the water phase, while the aqueous phase was at a lower temperature than the other experiment. Furthermore, the treatment efficiency was good as the heterogeneous catalysis was promoted by the micro-reaction condition of high interface temperature. Hydraulic retard time would influent the result by changing the contact time and interface temperature at the same time. The process of CWPOi presented good adaptability to the feed temperature, pH and inorganic anion conditions of the wastewater. The removal rate decreased with the extreme alkaline and high SO42-concentration dye wastewater.