Azo-dye treatment using different engineering approaches: a comparative review analysis

Azo dyes have emerged as a critical category of dyes in most sectors where color is essential. These dye classes are preferred in businesses because of their favorable properties, albeit at the expense of the environment and ecosystem. Various treatment methodologies are being investigated to degrade these azo dyes via different wastewater treatment approaches. Chemical approaches, especially those involving advanced oxidation processes, are preferred for rapid degradation, whereas biological approaches are widely preferred for various reasons, including their cost-effectiveness and sustainability. While, bio-chemical approaches can overcome the hurdles of both chemical and biological approaches. This review primarily centers on various chemical, biological, and biochemical methodologies and the critical elements involved in those processes. It employs bibliometric and scientometric studies to elaborate on azo dye degradation via the approaches above. Additionally, VOSviewer was used to demonstrate bibliometric mapping.