Predicting the dynamics and performance of a polymer-clay based composite in a fixed bed system for the removal of lead (II) ion
Chemical Engineering Research and Design
Department of Chemical Sciences, Redeemer's University, Km 46, Lagos Ibadan Expressway, PMB 3005, Redemption City, Mowe, Nigeria; Institute of Chemistry, Universität Potsdam, D-14476 Potsdam OT Golm, Germany; Chemical Engineering Department, Faculty of En
A polymer-clay based composite adsorbent was prepared from locally obtained kaolinite clay and polyvinyl alcohol. The composite adsorbent was used to remove lead (II) ions from aqueous solution in a fixed bed mode. The increase in bed height and initial metal ion concentration increased the adsorption capacity of lead (II) and the volume of aqueous solution treated at 50% breakthrough. However, the adsorption capacity was reduced by almost 16.5% with the simultaneous presence of Ca 2+/Pb 2+ and Na +/Pb 2+ in the aqueous solution. Regeneration of the adsorbent with 0.1M of HCl also reduced its adsorption capacity to 75.1%. Adsorption of lead (II) ions onto the polymer-clay composite adsorbent in the presence of Na + and Ca 2+ electrolyte increased the rate of mass transfer, probably due to competition between cationic species in solution for adsorption sites. Regeneration further increased the rate of mass transfer as a result of reduced adsorption sites after the regeneration process. The length of the mass transfer zone was found to increase with increasing bed height but did not change with increasing the initial metal ion concentration. The models of Yoon-Nelson, Thomas, and Clark were found to give good fit to adsorption data. On the other hand, Bohart-Adams model was found to be a poor predictor for the column operation. The polymer-clay composite adsorbent has a good potential for the removal of lead (II) ions from highly polluted aqueous solutions. © 2011 The Institution of Chemical Engineers.
Adsorption capacities; Adsorption data; Adsorption model; Adsorption site; Bed height; Bohart-Adams model; Breakthrough; Cationic species; Column operations; Composite adsorbents; Fixed bed; Fixed-bed modes; Kaolinite clay; Lead ions; Metal ion concentration; Regeneration; Regeneration process; Geologic models; Kaolinite; Lead; Mass transfer; Metal ions; Polymers; Solutions; Adsorption