Dyes adsorption using clay and modified clay: A review

The effective use of the sorption properties of different clays as sorbents for the removal of dyes from wastewater has currently received much attention because of the eco-friendly nature of clay materials. Dyes are complex class of organic compound having wide range of applications in textile and food industries and a large amount of dyes are wasted, which get mixed in natural water resources. Mixing of dyes in water resources must be prohibited for the safety of natural ecosystem. The adsorbents (natural and modified) have been successfully used for the adsorption of dyes form wastewater. This review article highlights the importance of clay (raw and modified) as an adsorbent for the adsorption of dyes from textile wastewater. Appropriate conditions for clay-dye system and adsorption capacities of a variety of clays are presented and sorption process is critically analyzed. Studies reported the clays as an adsorbent from 2004 to 2016 are included and different properties for the utilization of clay and clay-based adsorbents are discussed. Based on studies, it was found that the clays (natural and modified) are affective adsorbents for the purification of wastewater containing dyes.