Abstract:

Traditional technology of wet oxidation was often carried out under the situation of high temperature and pressure, which results in low efficiency of the reaction, serious wear of the reactor and harsh reaction conditions. And the degradation rate and efficiency was often under at a lower level. The objective of this study was to elucidate the mechanism degrading wastewater by using MW-CWPO, in which the production of hydroxyl radicals can be promoted, and hence improves the degradation of pollutants under relatively gentle conditions. In this research, p-nitro phenol (100 mg/L) was used as target pollutant, and carbon nanotubes and hydrogen peroxides were used as catalysts and auxiliary oxidant. It is investigated that the high power, high pressure, and high concentration of catalyst and oxidant can effectively improve the degradation efficiency of organic wastewater. Besides, it was found that MW radiation can promote hot spot (exceed 1000℃) formation on the surface of catalysts, which can enhance hydroxyl generation by the decomposition of oxidizers and dissolved oxygen at the condition of high temperature. Additionally, the catalysts after reaction were scanned by electron microscope and find that the surface of the carbon nanotube used in the experiment had no apparent modification, so that it can be reused for a long time. Since factors such as pressure can enhance the degradation rate of organic wastewater, they can be controllably modified to accelerate chemical reactions or improve degradation rate of actual chemical industry wastewater.

摘要：

针对高压微波催化湿式氧化技术（MW-CWPO）降解苯酚类废水进行了研究，实验设计了一种耐高压微波催化实验系统，选择对硝基苯酚（100 mg/L）为目标污染物，使用多壁碳纳米管和过氧化氢分别作为催化剂和氧化剂，研究发现高功率、高压、高浓度的催化剂和氧化剂均能有效促进对硝基苯酚的降解，并且在某些特定条件下（800 W，0.3 MPa）反应5 min后其降解率可以达到100%。此外，实验发现在优化条件下该技术对实际印染废水也有着很好的处理效果，上述研究结论可应用于实际工业生产中，通过人为控制压力、微波功率等因素以加速化学反应从而提高实际化工废水的降解率，实现污染物的降解和资源的可持续化利用。