ABSTRACT
Abstract: In every dyeing process, the bath is not exhausted completely. Draining-off of exhausted coloured dyebaths pollute water body in a typical way creating higher biological and chemical oxygen demand as well as solid content beside increase in temperature and pH. As a result, aquatic balance comes under threat. A few of the dye classes are self-hydrolysable and suppresses the colour problem within a few days while some of the colours possessing compact structure are slowly precipitated on microbes engaged in purifying the water body thus killing these and interrupting purification process. This chapter examines the wastewater load from various dyeing processes, methodology to characterise those and ways to reduce the load.
