STUDY ON ADSORPTION CAPACITY OF Fe(III) ON CARBON DERIVED FROM LOTUS ACTIVE BY SULFURIC ACID

Abstract

This paper focus on the adsorption of Fe(III) in aqueous solution on carbon derived from lotus  activated by sulfuric acid. The experiments were conducted using the following parameters: absorbent mass is 0.05g; the solution volume is 50 mL; pH = 2.5; shaking speed is 250 rounds/minute; equilibrium time is 120 minute at room teperature (25±1⁰C); optimal volume of adsorbent was 0.5 g (V_Fe(III)= 50mL; C_{o, Fe(III)} ~ 50 mg/L). In the temperature range of 303 - 323K, the values of ΔG^o < 0; ΔH^o = -6.65 kJ/mol implicates that the process is self-inflicted and exothermic. Description of adsorption process according to Langmuir and Freundlich isotherm models shows that Fe (III) adsorption on carbon lotus is suitable for Langmuir model. Maximum adsorption capacity is calculated by the Langmuir adsorption isotherm model as 35.71 mg/g at 298K. Moving capacity corresponds to the flow rate of 1.5; 2.0 and 2.5 mL/min of 20.61; 18.91 and 15.94 mg/g, respectively. HNO₃ of solution was used to recover Fe(III) with high effective elution.