Efficient removal of a food dye from wastewater onto coconut coir dust and its comparative illustration with other low-cost adsorbents

Abstract

Abstract Coloured waste water possessing toxicity in the form of various dyes were used in several industries including paper pulp, textile, food, paint etc. Bio sorption is one of the best alternative for dye removal from wastewater. Coconut coir dust (CCD) is a light weight material with great porosity and high air content, hence is chosen for the present study specimen. The current work addresses the removal of hazardous sunset yellow (SY) FCF, a coloring ingredient frequently used in the food industry, from wastewater.The uptake capacity in batch and column mode is 82 mg/g and 160 mg/g respectively. The SEM images before and after biosorption of SY onto CCD also supported the binding between the adsorbent-adorbate interface. The comparative uptake capacity of SY with other follows the order as sal flower, Eucalyptus leaf, mahua seed and coco dust with values of 26, 31, 43 and 82 mg/g respectively which is maximum in case of CCD. Adsorption parameters like effluent pH, effluent dye concentration, dose, and contact time were optimized for estimation of adsorption capacity and rate constants. The output was better at high pH and lower concentration of dye. The kinetic study suggested pseudo second order rate revealing both adsorbate-adsorbent interdependency. The isotherm supported Langmuir model with monolayer and uniform adsorption at the interfaces. The spiked effluent testing showed that tap water had the lowest adsorption percentage (91.82%) and tube well water had the greatest percentage (98.37%). The real sample analysis with lab to land approach justified sustainability and commercial viability of the present work.