Fe (II) Removal from Potable Water by using Powdered Activated Carbon Adsorbent

In this study, powdered activated carbon was used as absorbent to remove or reduce Fe (II) ions concentration in potable water. The adsorption behavior of Fe (II) ions was studied by varying parameters including dose of powdered activated carbon, pH, initial concentration of Fe (II) and contact time. Equilibrium adsorption isotherms and kinetics were also investigated based on Fe (II) adsorption tests. The result showed that an increase in contact time and adsorbent dosage resulted in increase of adsorption rate. The optimum condition of Fe (II) removal process was found at pH=3, 0.45 g adsorbent dosage, 10 mg/l initial concentration of Fe (II) and contact time of 30 min. The removal percent was equal to 99.97 at optimum condition. Langmuir and Freundlich models were employed to analyze the experimental data. The data showed well fitting with the freundlich model (R2 = 0.997) with n = 1.275. Analyzing the kinetic data by the pseudo-first-order and pseudo-second-order equations revealed that the adsorption of Fe (II) using PAC following the pseudo-first-order kinetic model with correlation coefficients (R2) equals to 0.997, 0.987, 0.990, 0.961 and 0.985 for 10, 20, 30, 40 and 50 mg/l Fe (II) concentrations, respectively. The experimental data fitted very well with the pseudo-first-order. Also results of thermodynamics studies indicates that the reaction is endothermic and spontaneous. Overall, treatment of polluted solution to Fe (II) by adsorption process using PAC can be considered as an effective technology.

Keywords:

Adsorption , Fe (II) , Powdered activated carbon , Isotherm modelling , Kinetics , Thermodynamic