Every industry now takes clean technology very seriously. Particularly in textile dying facilities, a lot of water, energy, dyeing colours, and chemicals are used. Significant issues with air and water pollution may result from this. The wastewater is quite colourful and smells poisonous. It also has high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels. Reactive dyes found in wastewater include orange OGR, red DB-8, black DN, and turquoise DG. It has been demonstrated that the type of dye, the dosage of coagulant, and the pH of the sample all affect how effectively dye is removed. Also, the effectiveness of COD and colour elimination in single-stage and multi-stage ozonation-biological process methods were studied. The functional groups of azo dye are changed by ozonation to produce more readily removable biodegradable byproducts. Ozonation changes the functional groups in azo dye, resulting in more biologically degradable byproducts that are simply eliminated through biological treatment. Activated sludge treatment as well as the coagulation-flocculation technique with 80% waste water removal efficiency. Sequencing batch reactor is a fill-and- draw activated sludge-based system for wastewater treatment and has been proposed as an alternative technique for treating industrial effluents. We briefed a promising novel technology for textile effluent de-colorisation in this chapter.