Mercury Ions removal from Aqueous solution by Functionalized Nano-cellulose

The removal of Mercury ions (Hg⁺²) by functionalized nano-Cellulose (FNC) were investigated using batch adsorption technique. The investigation was carried out by studying the influence of initial solution pH, adsorbent dosage, Time, initial concentration of Mercury ions (Hg⁺²) and temperature. The equilibrium data was analyzed using Langmuir, Freundlich, Dubinin-Radushkevich and Temkin adsorption isotherms. The results showed that equilibrium was reached within 75 min. The used adsorbent gave the highest adsorption capacity at pH 4.5. The experimental isotherm data were analysed and modelled. In the studied concentration range (0.5 –1.0 mmol L⁻¹) the maximum adsorption capacity, Langmuir's qmax, improved from 173 to 204 mg/g as the temperature increased from 298 to 328 K. The enthalpy ΔH° and entropy ΔS° values were respectively estimated at 2.228 kJ mol⁻¹ and 0.010 kJ K⁻¹ mol⁻¹. The adsorption of Mercury ions (Hg⁺²) on (FNC) is a spontaneous and endothermic process. It was shown that the adsorption of Mercury ions (Hg⁺²) could be described by the pseudosecond order equation, suggesting that the adsorption process is presumable a chemisorption,