Investigation of The Thermodynamic, Kinetic and Equilibrium Parameters of Batch Biosorption of Pb(II), Cu(II), and Ni(II) From Aqueous Phase using Low Cost Biosorbent

• Main Authors: Mohanad J. Mohammed-Ridha, Ali Shihab Ahmed, Nagham Nafea Raoof
• Format: Article
• Language: English
• Published: Al-Nahrain Journal for Engineering Sciences 2017-01-01
• Series: مجلة النهرين للعلوم الهندسية
• Subjects: Biosorption; biomass; isotherm models; biosorption kinetics; biosorption thermodynamics
• Online Access: https://nahje.com/index.php/main/article/view/108
• ISSN: 2521-9154; 2521-9162

In this study, low cost biosorbent ̶ inactive biomass (IB) granules (dp=0.433mm) taken from drying beds of Al-Rustomia Wastewater Treatment Plant, Baghdad-Iraq were used for investigating the optimum conditions of Pb(II), Cu(II), and Ni(II) biosorption from aqueous solutions. Various physico-chemical parameters such as initial metal ion concentration (50 to 200 mg/l), equilibrium time (0-180 min), pH (2-9), agitation speed (50-200 rpm), particles size (0.433 mm), and adsorbent dosage (0.05-1 g/100 ml) were studied. Six mathematical models describing the biosorption equilibrium and isotherm constants were tested to find the maximum uptake capacities: Langmuir, Freundlich, Redlich–Peterson, Sips, Khan, and Toth models. The best fit to the Pb(II) and Ni(II) biosorption results was obtained by Langmuir model with maximum uptake capacities of 52.76 and 36.97 mg/g for these two ions respectively. While for Cu(II) the corresponding value was 38.07 mg/g obtained with Khan model. The kinetic study demonstrated that the optimum agitation speed was 400 rpm, at which the best removal efficiency and/or minimum surface mass transfer resistance (MSMTR) was achieved. A pseudo-second-order rate kinetic model gave the best fit to the experimental data (R 2 = 0.99),  resulting in  mass transfer coefficient  values of 42.84× , 1.57×  , and 2.85×  m/s for Pb(II), Cu(II), and Ni(II) respectively. The thermodynamic study showed that the biosorption process was spontaneous and exothermic in nature.