Homogeneous and Heterogeneous Catalytic Ozonation of Textile Wastewater: Application and Mechanism

Abstract

This paper presents an overview of textile wastewater treatment by catalytic ozonation, highlighting the parameters of the process and accompanying mechanisms. Since more than 800,000 tons of dyes are produced annually and thousands of cubic meters of highly polluted textile wastewater have been emitted into the environment every day, this issue has become an environmental concern. Due to the high oxidative potential of ozone (2.08 V) and hydroxyl radical (2.80 V), the main reactive species in catalytic ozonation, the burdensome organic pollutants, including textile dyes, can be successfully decomposed. The paper shows the main groups of catalysts, emphasizing novel structural, nano-structured, and functionalized materials. The examples of catalytic ozonation in the industrial application for real textile wastewater were specially highlighted.

Perspective Applications of Plasma-Deposited Thin Film Nanocatalysts on Structured Supports: From CO2 Capture to Wastewater Treatment

“…The meshes were pre-calcined in air at 900 °C for 48 hours. The finer mesh, denoted as A, was employed in processes related to CO 2 conversion [45,48,50,51] while the looser one (B) was used in catalytic ozonation of wastewater [49]. Figure 3 provides an example of plasma-fabricated thin-film catalysts based on CoO x on the applied support.…”

“…Figure 9 shows the patented construction of an ozone bubble reactor equipped with baffles filled with a mesh coated by a thin-film catalyst (Fig. 8a) (P.445362 [49]) and the representation of the mesh function (Fig. 8b).…”

“…The chosen model pollutant for ozonation was textile dye, Reactive Black 5 (RB5), and the process efficiency was measured as overall rate constant (k dec ) of RB5 decolourisation. catalyst compared to non-catalytic process (initial concentration of RB5 50 mg/L, pH = 10, kdec is pseudo-first order rate constant of decolourisation) [49] Figure 10 illustrates the rate enhancement of RB5 ozonation in the presence of the catalyst compared to non-catalytic ozonation, based on our preliminary experiments [49]. The catalytic ozonation test was conducted in a basic aqueous medium (pH = 10), indicating a predominantly radical oxidation pathway under the applied conditions [68], leading to the enhanced production of reactive oxygen species (ROS) through the interaction of ozone with the nanostructure of the catalyst's surface.…”

“…10. Rate enhancement of RB5 dye decolourisation during ozonation with a thin-film CoOx (2)catalyst compared to non-catalytic process (initial concentration of RB5 50 mg/L, pH = 10, kdec is pseudo-first order rate constant of decolourisation)[49]…”

Data-Based Modeling, Multi-Objective Optimization and Multi-Criteria Decision Making of a Catalytic Ozonation Process for Degradation of a Colored Effluent

“…Researchers continue to explore more efficient techniques to address the drawbacks of the previous methods, such as low efficiency, high volumes of sludge and high operating/capital costs [6]. The ozonation process, mostly used with catalysts (i.e., the catalytic ozonation process, COP), is an efficient treatment when mineralization is desired [7]. Gutowska et al [8] concluded that ozonation is more effective compared to the Fenton process for the degradation of reactive orange 113 dye.…”