Comparison of dye wastewater treatment methods: A review

Wastewater is produced by numerous dyes producing and dye consuming industries in their process activities especially the textile industry. These effluents become toxic and harmful to the living things and the environment if not properly treated before being discharged to the environment. In recent decades dye wastewater has been becomes a growing water pollution problem because it is one of the most difficult to treat. To put an end to this problem, viable, efficient, and sustainable method of treatment of dye wastewater and color removal needs to be established. Several research papers have been done over the years on various treatment method of dye wastewater with evolving options; this paper is to bring together both the conventional and new methods. Some of the conventional and new methods researched over the years include activated sludge, coagulation, adsorption, membrane separation processes and electrochemical process etc. Although there is currently no uniform standard or method of treatment universally adopted, many countries have put in place allowable limits of composition of dischargeable wastewater. This paper seeks to explore which methods are highly efficient, produces manageable and recyclable waste and a combination/hybrid treatment option of these methods to achieve maximum color removal.