Acidified coconut husk as a potential biosorbent for adsorption of textile dye reactive yellow 160

Coconut husk could be employed as an environment friendly adsorbent for removal of various xenobiotics from the environment, especially the reactive dyes from the polluted waterbodies. In this study the Acidified Coconut Husk(ACH) with 0.1 N Hydrochloric acid was identified as a potentially low-cost biosorbent for the removal of Reactive Yellow 160(RY160) in aqueous solution. Optimization of various parameters such as the effect of agitation at shaker rotor speed of 120 rpm, adsorbent dosage ranging from 0.5-4%, initial dye concentration (200 to 1000 mg/L) and pH (3 to 11) were conducted and it was found that maximum adsorption percentage of 93% occurred with 4% adsorbent dosage at 200 mg/L initial dye concentration and pH 3 under agitating conditions. Adsorption was confirmed with the changes in FTIR spectrum, XRD and SEM of the ACH before and after adsorption. Adsorption kinetics studies proved a best fit into the pseudo second order kinetics model (R²= 0.9973) indicating chemisorption as the rate-limiting step of the process. Adsorption capacity(qe) of 4.56 mg/g fitted more into Langmuir isotherm model (R²= 0.9884) than Freundlich isotherm (R²= 0.8792) with Qmax value of 35.97 mg/g. Acidified coconut husk is proved as feasible adsorbent for textile dye removal from the aqueous environment.