The manuscript points out that while various treatment techniques have been developed to remove color from industrial wastewater, they each have significant limitations. Methods such as adsorption, coagulation, biological treatment, and ozonation are commonly used but face distinct challenges. Adsorption, for example, only transfers pollutants from the liquid phase to a solid phase, which then requires further disposal, making the process costly and less efficient. Coagulation can remove dispersed dyes but is ineffective for soluble dyes and generates large quantities of chemical sludge. Ozonation is effective but expensive, making it impractical for widespread industrial use. Biological treatments also fall short, particularly for azo dyes, as these are difficult to degrade aerobically, and under anaerobic conditions, they can produce even more hazardous by-products.

These shortcomings highlight a gap in the current literature, justifying the need for this study. The Sono-Fenton process, enhanced with natural clay, offers a more efficient, cost-effective, and environmentally friendly solution by combining the oxidative power of hydroxyl radicals with ultrasound, overcoming many of the drawbacks of existing methods.