Review on Greywater Treatment and Dye Removal from Aqueous Solution by Ferrate (VI)

Greywater reuse is an attractive option for the conservation of water resources and sustainable environmental management. The gap between available water resources and water demand is growing significantly. Safe and adequate quantity of water is essential for human beings and their health. Appropriate hygiene and water resources management can be done by greywater reuse. Usually, greywater flow from a household is around 65% of the total wastewater flow. Therefore, greywater has a big potential for recycle and reuse. Dyes are an important class of contaminants, and can even be recognized by the human eye. Release of dye containing wastewaters to valuable water resources must be avoided. However, specific treatment technologies are not available for the removal of dyes. Fe (VI) has several advantages as its high redox potential and coagulant properties. Fe (VI) are able to oxidize organic and inorganic contaminants successfully with its unique properties. This chapter highlights and provides an overview of greywater treatment applications by Fe (VI) which is lack in the literature. Disinfection efficiencies of Fe (VI) on greywater treatment and the removal of other pollution parameters such as COD, BOD5, surfactant and TOC can be found in this chapter. Also, removal of dye contents such as indigo, methylene blue, orange II, azo dye X-3B, acid yellow-36 by Fe (VI) and the applications of Fe (VI) for the treatment of real dye wastewater were evaluated in this chapter. Kinetic studies and treatment efficiencies for dye removal are also complied. In addition, many other methods used for the removal of dyes are also complied in brief. From a comprehensive literature review, it was found that Fe (VI) has fast kinetics and significant oxidation and adsorption capacities on both greywater treatment and dye removal.