Removal of Dyes from Effluents Using Biowaste-Derived Adsorbents

The removal of dyes from aqueous media has always been the focus of attention since the invention of the dyeing industry. Dyes not only disturb the visual appearance of the aquatic environment, but can also negatively affect human health due to their toxicological, carcinogenic and mutagenic nature. The hazards associated with these materials have inspired scientists to look for different technologies to remove these toxic substances from effluents. It is now well-established that adsorption/ion exchange is a much preferred technique over the traditional wastewater treatment methods owing to its ease of process, effectiveness and no sludge formation. Notwithstanding the very promising dye removal efficiency of activated carbon materials, their high cost has incited debate on the economic aspects of these materials. In the last few decades, researchers have employed many different types of waste materials to develop various porous carbonaceous and siliceous materials to act as adsorbents for dye removal. This chapter will primarily provide an overview of the relevant studies reported in literature undertaken to modify waste materials and use them for dye adsorption. Furthermore, the advantages and disadvantages of the waste-produced adsorbents, their comparative uptake capacities as well as the relevant challenges will be addressed.