This review critically examines the characteristics and constituents of synthetic effluents from the textile industry, focusing on the typical and real characteristics of textile effluents, the chemicals used to prepare synthetic wastewater, and the treatments applied to these effluents. Textile industries are major contributors to environmental pollution due to the release of dye effluents. These effluents contain dyes, metals, and other pollutants, with synthetic dyes being widely used due to their fastness and availability. The typical characteristics of textile effluents include high levels of colour, pH, suspended solids, chemical oxygen demand (COD), biochemical oxygen demand (BOD), metals, temperature, and salts. Real textile effluents vary significantly depending on the process, equipment, fabric type, and other factors. The main metals causing environmental challenges are chromium, zinc, iron, mercury, and lead. Dye concentrations in textile wastewater range widely, from 10–50 mg/l to as high as 7000 mg/l. Various treatment methods have been evaluated for the removal of dyes and other pollutants from real textile effluents, including ozonation, coagulation, activated sludge, electrochemical oxidation, nanofiltration, and constructed wetlands. Synthetic wastewater is essential for pilot-scale studies when real effluents are not available. The preparation of synthetic wastewater involves mixing dyes, metals, and other chemicals to match the characteristics of real effluents. The review summarizes the reported constituents used for preparing synthetic textile wastewater and their treatment, highlighting the importance of matching these constituents to the typical characteristics of textile effluents. The review also discusses the chemical and physical methods used for treating synthetic textile wastewater, including advanced oxidation processes, adsorption, and filtration. The study emphasizes the need for further research to develop effective and sustainable treatment methods for textile effluents.This review critically examines the characteristics and constituents of synthetic effluents from the textile industry, focusing on the typical and real characteristics of textile effluents, the chemicals used to prepare synthetic wastewater, and the treatments applied to these effluents. Textile industries are major contributors to environmental pollution due to the release of dye effluents. These effluents contain dyes, metals, and other pollutants, with synthetic dyes being widely used due to their fastness and availability. The typical characteristics of textile effluents include high levels of colour, pH, suspended solids, chemical oxygen demand (COD), biochemical oxygen demand (BOD), metals, temperature, and salts. Real textile effluents vary significantly depending on the process, equipment, fabric type, and other factors. The main metals causing environmental challenges are chromium, zinc, iron, mercury, and lead. Dye concentrations in textile wastewater range widely, from 10–50 mg/l to as high as 7000 mg/l. Various treatment methods have been evaluated for the removal of dyes and other pollutants from real textile effluents, including ozonation, coagulation, activated sludge, electrochemical oxidation, nanofiltration, and constructed wetlands. Synthetic wastewater is essential for pilot-scale studies when real effluents are not available. The preparation of synthetic wastewater involves mixing dyes, metals, and other chemicals to match the characteristics of real effluents. The review summarizes the reported constituents used for preparing synthetic textile wastewater and their treatment, highlighting the importance of matching these constituents to the typical characteristics of textile effluents. The review also discusses the chemical and physical methods used for treating synthetic textile wastewater, including advanced oxidation processes, adsorption, and filtration. The study emphasizes the need for further research to develop effective and sustainable treatment methods for textile effluents.