Linearized Forms of Langmuir Equations and Its Effect on the Prediction of Biosorption of Cr (VI) on Neem Leaf Powder

In order to understand the biosorption mechanism of Cr (VI) on to Neem leaf powder (NLP), the experimental data needs to be fitted onto a linearized form of isotherm equations. The Langmuir isotherm has five different linearized equations, and each form is generating a different constant for adsorption equilibrium based on KL and qmax. The effect of linearized forms of Langmuir isotherms (LL) is studied in this work. KL, qmax was calculated using five different linearized forms of Langmuir isotherm and compared. R2 values of these LL varied drastically between 0.577 to 0.974. From the calculated KL and qmax, qe was predicted and plotted. When these predicted values and experimental values were compared, LL4 was found to be the best suited linearized form despite not having the highest correlation coefficient. The LL2 and LL4 having highest correlation coefficient showed high overshoot for predicted values over experimental values.