Biosorption of dicloxacillin from pharmaceutical waste water using tannin from Indian almond leaf: Kinetic and equilibrium studies

This study focused on the use of Indian almond leaf biomass, a local plant widely found in Thailand, on removal of dicloxacillin from pharmaceutical waste water by biosorption. The biosorption characteristics of dicloxacillin were investigated in terms of equilibrium, kinetics and thermodynamics. Optimum biosorption conditions were determined from pH, initial dicloxacillin concentration, biomass dosage, contact time, and temperature. The maximum adsorption capacity was 86.93 % (pH 6.0, 0.1 g/L biomass, dicloxacillin concentration 20 mg/L, contact time 24 h, temperature 283.15 K). The thermodynamic parameters (298.15 K), free energy change, enthalpy change and entropy change were -3475.79 J/mol, −25.36 kJ/mol, and −73.40 J/mol/K, respectively. The best interpretation for the experimental data was given by the Langmuir isotherm with correlation coefficient of 0.965. The results were found to tie in well with pseudo-second-order kinetics. Considering the cost-effectiveness, Indian almond leaf biomass is considered to be suitable to remove dicloxacillin from pharmaceutical waste water.