where Ce and qe are the equilibrium liquid-phase concentrations of Alizarin Red S dye (mg/L) and amount of Alizarin Red S adsorbed onto mustard husk biomass (mg/g), respectively. Q0 is the maximum adsorption capacity reflected on a complete monolayer (mg/g); KL is the adsorption equilibrium constant (L/mg) that is related to the apparent energy of sorption. The Langmuir isotherm parameters can be obtained from its linearized form as shown in Eq. (8) [35]: