Enhanced removal of RB5 pollutant via sono-catalytic activation of potassium peroxydisulfate using Porous/ZIF-8

Abstract

In recent years, the proper integration of various advanced oxidation processes has posed a new challenge. As synergy plays a critical role in integrated processes, it is highly essential to develop an integrated process that is not only effective but also economically feasible. In this study, the integration of sonochemical process for efficient activation of potassium peroxydisulfate (PDS) was used with ZIF-8 and Porous/ZIF-8 catalysts, resulting in the creation of an indirect photocatalytic process assisted by ultrasonic waves. The Porous/ZIF-8 sample with higher porosity (233.67 m2/g) than ZIF-8 (183.61 m2/g) was prepared using a polystyrene template. The created porosity leads to an increase in active reaction sites, which is effective in improving the efficiency of pollutant removal. A comprehensive investigation was conducted to analyze the effects of various operational parameters, namely pH, catalyst concentration, and initial pollutant concentration, on the removal efficiency (RE), pseudo-first-order kinetic rate constant (kapp), and synergistic factor (SF) of reactive black 5 (RB5). The optimum operational conditions were determined as pH = 5, 0.6 g/L [Porous/ZIF-8], and 10 mg/L [RB5]. The integrated process proposed in this study demonstrates a high level of acceptability and environmental friendliness, owing to its remarkable SF and novel characteristics.