Evaluation of Some Eco-Friendly Food Residues for Removal of Methylene Blue Dye from Aqueous Solutions

Walnut shell (WS) powder and eggshell (Eg) powder were grounded and sieved using a ۷۵ µm hole diameter sieve. Both WS and Eg powders were characterized by SEM and IR technologies, and their adsorption capacity was tested towards Methylene blue dye (MB). The tested parameters for MB removal efficiency (RE) were contact time, initial dye concentration, and temperature. It was found that RE of ۲۰ mg/L MB equaled ۶۵.۸۶% after ۱۰ min and ۶۴.۸۲ % after ۳۰ min in the presence of WS and Eg, respectively. For ۲۰, ۴۰, ۶۰, ۸۰ and ۱۰۰ mg/L of MB, RE using WS equalled to ۶۵.۸۷%, ۷۱%, ۷۱.۸%, ۷۲% and ۷۲.۳۴ respectively. However, using Eg, RE for the same concentrations of MB was noticed to be ۶۰.۰۱%, ۵۵.۲۳%, ۵۱.۶۲%, ۴۶.۰۱%, and ۴۴.۵۲%, respectively. At varing temperatures, for ۲۰ mg/L of MB, the RE was ۶۹.۳۴%, ۷۲.۵%, ۶۹.۴۴%, and ۶۹.۸۵% at ۲۵, ۳۵, ۴۵, and ۵۵°C on order using WS powder. While at the same temperatures, RE was ۶۴.۲۱%, ۶۵.۲۱%, ۶۵%, and ۶۴%, respectively, using Eg powder. It can be concluded that WS powder has shown greater adsorption capacities towards MB than Eg powder.

Keywords:

Adsorption , MB dye , Wastewater Treatment , Removal Efficiency , Walnut shell micro-powder , SEM , Eggshell micro-powder