A KrCl exciplex flow-through photoreactor for degrading 4-chlorophenol: Experimental and modelling

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• 作者：M. Gomez ; ^{maria.gomez@um.es} ; M.D. Murcia ; J.L. Gomez ; E. Gomez ; M.F. Maximo ; A. Garcia
• 关键词：4-Chlorophenol ; Kinetic model ; Photodegradation ; UV ; Excil KrCl photoreactor
• 刊名：Applied Catalysis B ; Environmental
• 出版年：2012
• 期刊代码：4_09263373
• 类别：ce
• 出版时间：18 May, 2012
• 卷：117-118
• 期：Complete
• 页码：194-203
• 文件大小：702 K

摘要

A KrCl exciplex flow-through photoreactor has been used for the removal of 4-chlorophenol. UV/H₂O₂ and photo-Fenton processes were tested. Considering the degradation of the different compounds, the molar ratio H₂O₂:4-chlorophenol did not show a significant influence on 4-chlorophenol while an optimum ratio of 25:1 was established for the photoproducts. The presence of the Fenton reagent led to a considerable improvement in the photodegradation of both the substrate and by-products, and an optimum Fe²⁺ concentration of 5 mg L^鈭? was determined. Under these conditions, total degradation was attained for a range of substrate concentrations between 50 and 150 mg L^鈭? and for reaction volumes of 500 ml. A photodegradation mechanism was also proposed, based on the formation of two intermediate compounds that quickly degrade to the primary photoproducts previously identified. A kinetic model was developed and theoretical conversion values of the 4-chlorophenol and the photoproducts were compared with the experimental ones, reaching a high degree of agreement (x_calc = 0.9964 x_exp, R² = 0.9986) and validating the proposed model. This system simulation using relatively high reaction volumes and including the by-products in the kinetic equations represents a first approach with a view to operating in continuous or semi-continuous systems that allow the scaling up of the process.