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Azo dye wastewater with deep color, high concentrations of pollutants, biological toxicity, biodegradation and other characteristics, using conventional methods are difficult to deal with, and explore less investment, high treatment efficiency of treatment process is currently manufacturing and dye printing and dyeing industry, an urgent need to solve the problem. This study uses microwave-assisted Fenton wet oxidation method, microwave assisted K2S2O8/Fe0 wet oxidation of methyl orange azo dye simulated wastewater treatment, the single factor experiments under controlled conditions to study the various process parameters on Dye Wastewater efficiency; to explore methyl orange in microwave-assisted wet oxidation process under the possible degradation pathways for processing water samples were UV - visible absorption spectroscopy (UV-vis), high performance liquid chromatography (HPLC) , gas chromatography - mass spectrometry (GC-MS) analysis of water samples were measured COD, total nitrogen, nitrate, nitrite, ammonia changes. The results showed that: (1) MW / Fenton process the initial concentration of 100mg / L of methyl orange simulated wastewater optimal conditions for: pH = 3.0, temperature 60 ℃, 3% H2O2 dosage is 1ml, Fe2 concentration of 0.12 mmol / L, a microwave power of 500W, the reaction time is 8min. At this point, decolorization rate reached 98.7%, COD Cr , removal rate reached 54.2%; (2) MW/K2S2O8/Fe0 handle the initial concentration of 100mg / L of methyl orange simulated wastewater Best conditions: natural pH conditions, the temperature is 60 ℃, K2S2O8 dosage of 3.0mg, reducing iron dosage 0.9mg, microwave power is 500W, the reaction time was 8min. At this point, decolorization rate reached 99.6%, CODCr removal rate reached 84.4%; (3) methyl orange in MW / Fenton and MW/K2S2O8/Fe0 two processes are a reaction under the reaction, after the introduction of the microwave, degradation of methyl orange were significantly lower activation energy; (4) Both processes degradation of methyl orange under basically the same, roughly consists of three phases: first, methyl orange chromophore and conjugated structure was destroyed occurred bleaching reaction intermediate with a single benzene ring; then with benzene ring opened intermediate benzene; end, open-loop intermediate product is further oxidized to carbon dioxide and water, thus methyl orange was completely oxidized. This study addresses the traditional processing method dye wastewater degradation efficiency is low, the shortcomings of low salinity for microwave-assisted wet oxidation dye wastewater treatment process design and process optimization provides reference data for the realization of the industrial application of this technology provides an experimental and theoretical basis.
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