On-line attenuated total reflection infrared spectroscopy (ATR-IR) was used to gain a good understanding of the kinetics and mechanism for methyl cyclopentenone (MCP) synthesis from 2-methylfuran and formaldehyde in a...

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A large amount of volatile organic compounds (VOCs) produced by industry have caused serious environmental pollution. In this paper, the removal effect of simulated xylene by strong ionization dielectric barrier discharge (DBD) plasma at atmospheric pressure and its degradation mechanism and pathway were studied. The effect of gas residence time, and initial xylene concentration was studied. The results showed that higher voltage caused an increase in discharge power, and with the increase of voltage, the concentration of ozone and nitrogen oxide in the reactor increased. The degradation efficiency decreased from 98.1% to 80.2% when xylene concentration increased from 50 ppm to 550 ppm at 4kV. And with the increase of residence time from 0.301s to 1s, the degradation efficiency increased from 78.5% to 98.6%. According to GC-MS analysis, the degradation products were ethyl acetate and n-hexylmethylamine at 4kv. And the main intermediates are 2,4-2-tert-butylphenol, 2-aminopentane, 2-methyl-5 - (2-aminopropyl) - phenol and propionamide at 1.5kV.

In a wastewater treatment plant, there are some problems that the impellers of submersible mixers were damaged with abrasion and the impellers’ spare parts must be imported. To solve this problem and realize domestic manufacture, based on reverse engineering theory, utilizing three coordinates measuring machine and applications of Surface and Pro/E, then the Pro/E software was used to develop the impeller solid model. The gained impeller model accords with the physical one with high accuracy. By using this model, the manufacture of its mould and research on abrasion-resistant performance as well as the implementation of domestic manufacture of its parts are completed. The new impeller has been employed in this plant and passed field running experiment. The results indicate that its mixing and propelling performance is excellent and abrasion does not happen in more than three months. It has prominent economic and social benefit.