Unformatted text preview: electrogenerative system was evaluated based on various parameters: initial lead(II) nitrate concentration, choice of cathode material used, supporting electrolyte concentration and acidity of anolyte and catholyte solutions. More than 90 % lead was recovered within 3 h of operation by using porous graphite. The recovery of lead was 100 % after 1 h of operation using a reticulated vitreous carbon a s a cathode. X-Ray diffraction analysis and scanning electron microscopy were used to visualize the lead deposits. 78 3rd ICYC 2010 Universiti Sains Malaysia ANA-P6 23rd-25th June 2010 ADSORPTION OF HUMIC ACID FROM AQUEOUS SOLUTIONS ONTO CHITOSAN COMPOSITE Norhashida Tajudin and Wan Saime Wan Ngah School of Chemical Sciences, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia E-mail: [email protected] Cross-linked chitosan coated bentonite (CCB) beads were synthesized, characterized and were used for adsorption of humic acid from aqueous solutions. The CCB beads were characterized by Fourier Transform Infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer -EmmettTeller (BET) surface area. The effects of pH, dosage, stirring rate, initial concentrations, contact time and temperature were studied in a batch adsorption system. The kinetic, thermodynamic and adsorption isotherms of humic acid onto CCB beads were studied in order to understand the behaviour and mechanism of adsorption. The equilibrium adsorption data were described by t he Langmuir, Freundlich, BET, Sips, Temkin and Dubinin-Radushkevich isotherms. CCB beads agreed well with the Langmuir -1 isotherm, which gave maximum adsorption capacity of 62.9 mg g at 320 K. The pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models were employed to analyze the kinetic data. The adsorption behaviour of humic acid was best de scribed by the pseudo-second order model. o o The thermodynamic parameters such as free energy change (ΔG ), enthalpy change (ΔH ) and entropy o change (ΔS ) were computed. The adsorption process...
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This note was uploaded on 02/17/2011 for the course CHEMISTRY 101 taught by Professor Csr during the Spring '11 term at University of Louisville.
- Spring '11