**2. Treatment of dye-contaminated water in adsorption procedure**

Several techniques have been reported to be able of alleviating the occurrence of organic dye in contaminated industrial effluents, and these include flocculation, membrane filtration, biodegradation, chemical degradation, and photochemical treatment [11]. Although these treatment procedures have been applied successfully, they have also displayed shortcomings like high operational costs, low selectivity and toxic sludge production. Adsorption procedure, on the other hand, has frequently been described as a promising approach for wastewater treatment because of the reasons like simplicity in design, low operational cost and comparatively high efficiency [12, 13]. Furthermore, this treatment procedure can be applied on a large scale, as it can handle large flow rates and yields a high quality of water without producing sludge and residuals [14].

Numerous adsorbents are reported in the literature for the removal of contaminants in wastewater, and these include activated carbon, clay minerals, zeolites, industrial wastes, metal oxides, and polymeric materials [15–20]. Among these adsorbents activated carbon is the most widely employed material for the removal of dye in aqueous solution due to its high surface area [21]. However, activation of carbon sources is energy-intensive and requires the use of expensive chemicals and equipments. The low regeneration of spent activated carbon also restricts its practical application. A large majority of the reported adsorbents are also associated with drawbacks like non-biodegradability and low efficiency. These limitations can be overcome using naturally occurring "green" polysaccharide adsorbents owing to their cost-effectiveness, ease availability, and biodegradability.
