Continuous degradation of 1,4-dioxane by the combination of a stripping column and photo-Fenton reaction in a continuous stirred tank reactor

1,4-Dioxane is a toxic chemical that is used in the chemical industry. The limit concentration of 1,4-dioxane in environment was set at 0.3 mg/kg. Here, for efficient degradation of 1,4-dioxane, combined use of a stripping column and a continuous stirred tank reactor (CSTR) is proposed. The stripping column concentrates 1,4-dioxane, and photo-Fenton reaction in the CSTR decomposes 1,4-dioxane by OH radicals generated by an ultraviolet lamp. In the photo-Fenton reaction, the pseudo-first-order reaction constant was determined to be 1.88 x 10-4 1/s at 318 K. The separation coefficient of 1,4dioxane, the ratio of the concentrations at the top and bottom of the stripping column, was approximately 500-2700 depending on the heat supplied to the column. The optimum combination of the stripping column and CSTR was investigated on the basis of three proposed models. The order of degradation in the CSTR followed by concentration in the stripping column, along with circulation from the top of the column to the CSTR, gave an overall reaction percentage of 99.9%. From energy calculation, a higher separation coefficient (alpha) decreased the total heat duty from 4.5 x 104 J/min at alpha = 640-1.2 x 104 J/min at alpha = 2400. A stripping column for concentration of 1,4-dioxane combined with a CSTR for photo-Fenton reaction shows potential for efficient degradation of 1,4-dioxane. (c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.