Nonlinear and Linear Analysis of Langmuir Adsorption Isotherm for Removal of Copper from its Aqueous Solution Using Cucumber Peel

Abstract

Adsorption is a unit operation of separating solute from solution using another solid material. Modelling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in adsorption science. The main aim of the present work is to analyse various forms of Langmuir isotherm for adsorption of copper from its aqueous solution using cucumber peel from the batch experimental data. The linearized and nonlinearized isotherm models were compared and discussed. In order to determine the best fit isotherm model, the determination coefficient (R2) and sum of square of error (SSE) for each model were used. The modelling results showed that nonlinear Langmuir model could fit the data better than other forms, with relatively higher R2 values (0.9879) and smaller SSE (0.013). The linear forms of Langmuir model had the maximum adsorption capacities deviated from the experimental data. The maximum adsorption achieved was 66.61 mg/g after validation with experimental results.