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The application of microwave activated Acacia nilotica leaves (MVM) and chemically activated A. nilotica leaves (CVM) for the removal of crystal violet (CV) from aqueous solution was studied in a batch system. Equilibrium sorption isotherms and kinetics were investigated. The applicability of the Langmuir model for CV onto CVM and MVM was proved by the high correlation coefficient and non-linear regression such as, residual root mean square error (RMSE), chi-square (χ2), sum of the square of the errors (ERRSQ), composite functional error (HYBRD), derivative of Marquardt’s percent standard deviation (MPSD), average relative error (ARE), sum of absolute error (EABS) and average percentage error (APE). The adsorption of CV onto CVM and MVM follows pseudo-second-order kinetic model with intraparticle diffusion is one of the rate-limiting steps. The adsorption capacity of MVM is greater than CVM. The preparation of MVM is agreeing with the principles of green chemistry. Therefore, the eco friendly adsorbent MVM is expected to be the environmentally and the economically feasible adsorbent for the removal of CV from aqueous solution.

In the present study a biomass derived from the leaves of Acacia nilotica was used as an adsorbent material for the removal of cadmium and lead from aqueous solution. The effect of various operating variables, viz., adsorbent dosage, contact time, pH and temperature on the removal of cadmium and lead has been studied. Maximum adsorption of cadmium and lead arises at a concentration of 2 g/50 ml and 3 g/50 ml and at a pH value of 5 and 4, respectively. The sorption data favored the pseudo-second-order kinetic model. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models were applied to describe the biosorption isotherm of the metal ions by A. nilotica biomass. Based on regression coefficient, the equilibrium data found were fitted well to the Langmuir equilibrium model than other models. Thermodynamic parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) have been calculated, respectively revealed the spontaneous, endothermic and feasible nature of adsorption process. The activation energy of the biosorption (Ea) was estimated as 9.34 kJ mol−1 for Pb and 3.47 kJ mol−1 for Cd from Arrhenius plot at different temperatures.

The use of cheap and eco friendly adsorbents prepared from freely and abundantly available Acacia nilotica leaves have been investigated by batch methods. Microwave treated A. nilotica leaves (MVM) are more effective than chemically treated A. nilotica leaves (CVM) for the removal of rhodamine B (RH B) from aqueous solution. The effect of initial pH, contact time and initial dye concentration of RH B onto CVM and MVM has been investigated. The applicability of the linear form of Langmuir model to CVM and MVM was proved by the high correlation coefficients R2 = 0.9413 and 0.9681 for RH B adsorption. The R2 values were greater than 0.994 for all RH B concentrations, which indicates the applicability of the pseudo-second-order kinetic model. The recycling ability of MVM is greater than CVM. The preparation of MVM does not require an additional chemical treatment step and it attains rapid equilibrium. Hence it is agreeing with the principles of green chemistry and less time is required to possess high adsorption of RH B. Therefore, the eco friendly adsorbent MVM is expected to be environmentally and economically feasible for the removal of RH B from aqueous solutions.

The application of microwave activated Acacia nilotica leaves (MVM) and chemically activated A. nilotica leaves (CVM) for the removal of crystal violet (CV) from aqueous solution was studied in a batch system. Equilibrium sorption isotherms and kinetics were investigated. The applicability of the Langmuir model for CV onto CVM and MVM was proved by the high correlation coefficient and non-linear regression such as, residual root mean square error (RMSE), chi-square ( χ 2 ), sum of the square of the errors (ERRSQ), composite functional error (HYBRD), derivative of Marquardt’s percent standard deviation (MPSD), average relative error (ARE), sum of absolute error (EABS) and average percentage error (APE). The adsorption of CV onto CVM and MVM follows pseudo-second-order kinetic model with intraparticle diffusion is one of the rate-limiting steps. The adsorption capacity of MVM is greater than CVM. The preparation of MVM is agreeing with the principles of green chemistry. Therefore, the eco friendly adsorbent MVM is expected to be the environmentally and the economically feasible adsorbent for the removal of CV from aqueous solution. [ABSTRACT FROM AUTHOR]

In the present study a biomass derived from the leaves of Acacia nilotica was used as an adsorbent material for the removal of cadmium and lead from aqueous solution. The effect of various operating variables, viz., adsorbent dosage, contact time, pH and temperature on the removal of cadmium and lead has been studied. Maximum adsorption of cadmium and lead arises at a concentration of 2 g/50 ml and 3 g/50 ml and at a pH value of 5 and 4, respectively. The sorption data favored the pseudo-second-order kinetic model. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models were applied to describe the biosorption isotherm of the metal ions by A. nilotica biomass. Based on regression coefficient, the equilibrium data found were fitted well to the Langmuir equilibrium model than other models. Thermodynamic parameters such as free energy change (Δ G °), enthalpy change (Δ H °) and entropy change (Δ S °) have been calculated, respectively revealed the spontaneous, endothermic and feasible nature of adsorption process. The activation energy of the biosorption (Ea) was estimated as 9.34 kJ mol −1 for Pb and 3.47 kJ mol −1 for Cd from Arrhenius plot at different temperatures. [ABSTRACT FROM AUTHOR]

The use of cheap and eco friendly adsorbents prepared from freely and abundantly available Acacia nilotica leaves have been investigated by batch methods. Microwave treated A. nilotica leaves (MVM) are more effective than chemically treated A. nilotica leaves (CVM) for the removal of rhodamine B (RH B) from aqueous solution. The effect of initial pH, contact time and initial dye concentration of RH B onto CVM and MVM has been investigated. The applicability of the linear form of Langmuir model to CVM and MVM was proved by the high correlation coefficients R² = 0.9413 and 0.9681 for RH B adsorption. The R² values were greater than 0.994 for all RH B concentrations, which indicates the applicability of the pseudo-second-order kinetic model. The recycling ability of MVM is greater than CVM. The preparation of MVM does not require an additional chemical treatment step and it attains rapid equilibrium. Hence it is agreeing with the principles of green chemistry and less time is required to possess high adsorption of RH B. Therefore, the eco friendly adsorbent MVM is expected to be environmentally and economically feasible for the removal of RH B from aqueous solutions. [ABSTRACT FROM AUTHOR]