Efficient TOC Removal of Wastewater Containing 1,2-Naphthoquinone-2-diazido-5-sulfonic Acid Sodium Salt with H₂O₂/UV in a Batch Reactor

Abstract

Total organic carbon (TOC) removals of the synthetic wastewater and of the raw industrial wastewater discharged from LSI photo-resist processing of which main component is 1,2-naphthoquinone-2-diazido-5-sulfonic acid sodium salt (abbreviation naphthoquinone-5), have been carried out by using hydrogen peroxide and ultraviolet irradiation (H₂O₂/UV). Experiments were carried out in a batch reactor with a low pressure UV lamp (500 W) irradiating ultraviolet of 254 nm and of 185 nm (5% of energy). The following results were obtained. (1) TOC removals of the synthetic wastewater and of the raw industrial wastewater are pseudo-first-order processes, and TOC shows zero in about ten and several hours. (2) The TOC removal rate of the wastewater was governed by the concentration of hydrogen peroxide initially added and by the maximum pseudo-first-order rate constant and the optimum initial hydrogen peroxide concentration both existed in the synthetic wastewater and in the raw industrial wastewater. (3) The relation between the initial TOC concentration and the optimum initial hydrogen peroxide concentration exhibited linear both in the synthetic wastewater and in the raw industrial wastewater. The optimum initial hydrogen peroxide concentration in TOC removal of the raw industrial wastewater is same as that in the synthetic wastewater at the given initial TOC concentration. (4) The maximum pseudofirst-order rate constant increases with the decrease in the initial TOC concentration both in the synthetic wastewater and in the raw industrial wastewater. (5) A theoretical consideration was carried out and could explain with experimental results.