UV / Fe0 / H2O2 降解乙苯气体的工艺研究.

In order to settle the environmental issues with the accelerated development of industrial field, the present work was executed with gaseous ethylbenzene as the target pollutant, and zero-valent iron (Fe0) was selected as the catalyst of the Fenton reaction instead of Fe2+. The catalytic capacity of UV/Fe0/H2O2 system was evaluated by the degradation of gaseous ethylbenzene. Considering the complexity of actual reaction, various factors on the degradation efficiency were inquired systematically in this work such as initial H2O2 concentration, pH and [H2O2/Fe0] molar ratio. The changes in concentration of H2O2 and iron substance were analyzed thoroughly in the degradation process. Simultaneously, the GC-MS was conducted to study the intermediate adducts in the solution at different reaction phases. To sum up, the 48 μm industrial grade Fe0 was served as the catalyst. The removal efficiency of gaseous ethylbenzene in UV365/Fe0/H2O2 system could reach 67.5% within 45 min when 100 mmol·L-1 H2O2 was introduced, and the molar ratio of [H2O2]/[Fe0], initial pH value were adjusted to 40 and 3, respectively. Liquid intermediates were detected in different time periods, such as toluene, phenethyl alcohol, acetophenone, benzaldehyde, 1-propanol and methyl vinyl ketone, and no gaseous intermediates were detected. Moreover, the insufficient concentration of H2O2 after 45 min reduced the removal efficiency, and the stable concentration of H2O2 in the system could degrade ethylbenzene gas efficiently for a long time. Continuous leaching of Fe2+ from Fe0 could enable excellent iron cycling performance in this reaction system. [ABSTRACT FROM AUTHOR]