Methylene blue dye: Toxicity and potential elimination technology from wastewater One of the popular cationic dyes that is environmentally persistent, toxic, carcinogenic and mutagenic is methylene blue (MB) dye. It is commonly applied as synthetic dye for dyeing fabrics in clothing and textile industries and also for dyeing papers and leathers. Sequel to the magnitude of industrial usage, a large volume of methylene blue dye containing wastewater is discharged into groundwater and surface wate...