Catalytic Oxidation Process for the Degradation of Synthetic Dyes: An Overview

Abstract

Dyes are used in various industries as coloring agents. The discharge of dyes, specifically synthetic dyes, in wastewater represents a serious environmental problem and causes public health concerns. The implementation of regulations for wastewater discharge has forced research towards either the development of new processes or the improvement of available techniques to attain efficient degradation of dyes. Catalytic oxidation is one of the advanced oxidation processes (AOPs), based on the active radicals produced during the reaction in the presence of a catalyst. This paper reviews the problems of dyes and hydroxyl radical-based oxidation processes, including Fenton’s process, non-iron metal catalysts, and the application of thin metal catalyst-coated tubular reactors in detail. In addition, the sulfate radical-based catalytic oxidation technique has also been described. This study also includes the effects of various operating parameters such as pH, temperature, the concentration of the oxidant, the initial concentration of dyes, and reaction time on the catalytic decomposition of dyes. Moreover, this paper analyzes the recent studies on catalytic oxidation processes. From the present study, it can be concluded that catalytic oxidation processes are very active and environmentally friendly methods for dye removal.

Genome-enabled discovery of anthraquinone biosynthesis in Senna tora

“…Anthraquinones are aromatic polyketides made by bacteria, fungi, insects, and plants 18,19 . Besides their medicinal benefits, natural anthraquinones are garnering attention as alternatives to synthetic dyes that damage aquatic ecosystems [20][21][22] . Bacteria, fungi, and insects make anthraquinones via a polyketide pathway using complex polyketide synthase enzymes 18,23 .…”

The improved photocatalytic activity of highly expanded MoS2 under visible light emitting diodes

“…For the past decades, many methods have been introduced to remove the dye pollutant effectively from the wastewater which includes, adsorption [4], photocatalytic degradation [5], catalytic oxidation [6] and biological process [7]. Amongst them, photocatalytic degradation has been widely reported as an efficient and biosafety remedy [8].…”

Integrated Membrane–Electrocoagulation System for Removal of Celestine Blue Dyes in Wastewater

“…Currently, there are wide ranges of treatments used in the industry for removing dye in wastewater, such as biological treatment [ 8 , 9 , 10 ], fenton oxidation [ 11 , 12 ], membrane separation [ 13 , 14 ] and physiochemical treatment [ 15 , 16 ]. However, these methods pose a few major drawbacks, such as their high operation cost, larger formation of sludge, time consuming (long retention time) and the production of toxic by-products [ 17 , 18 ].…”