ABSTRACT

This research investigates the removal of the dyes, methyl orange (MO) and methyl blue (MB) from aqueous environment using two biosorbent materials, namely, orange and yam peels. Samples of orange and yam peels were analysed using UV-Visible spectrophotometer. These two selected biosorbents were studied under varying experimental conditions such as: contact time, temperature, pH, dye concentrations among others. The kinetics of sorption were well correlated using the pseudo first and second order constants ranging from 0.742gmg-1min for methyl orange and 5.741gmg-1min for methyl blue. The results of these experiments were modeled using Langmuir and Freundlich isotherm, some of the RL values at all four temperatures used did not fall between 0-1 while all KF values for Freundlich isotherm model fell between 1-10 this implies that these two locally available adsorbents, fitted completely into Freundlich but partly into Langmuir model. Other parameters like sorption capacity, sorption maximum were also determined. The calculated sorption maximum capacities are 46.67% (1.67mg/g), for yam peel and 42.04% (1.57mg/g) for orange peel at 318K. It was observed that sorption increases with increase in temperature in Kelvin for the two biosorbents studied. The isotherm models evaluated showed that the two biosorbents have significant potentials as adsorbents for the removal of methyl orange and methyl blue colours from aqueous environments.The results obtained shows that modified and unmodified powdered orange and yam peels, MOP, MOP, UOP and UYP are promising and cheap adsorbent that can be used for the removal of the methyl orange and methyl blue from solutions. It is therefore recommended that, modified and unmodified orange peel and yam peel should be used to adsorb waste water and solutions contaminated with dyes for industrial and domestic usage, they are easy and cheap to afford.