Removal of Pb(II) from solution using cellulose-containing materials

The potential of cheap cellulose-containing natural materials such as coir, jute, sawdust and groundnut shells for removal for Pb(II) from aqueous solution of lead nitrate was assessed before and after modifying them with a monochlorotriazine type of dye. The materials showed enhanced adsorption capacity of Pb(II) due to the specific dye loading. This was attributed to chelation and an ion exchange mechanism. The maximum cation uptake values obtained were 0.127, 0.087, 0.090, and 0.106 mmol g(-1) for coir, sawdust, jute and groundnut shell in their dyed forms, respectively. The kinetics of both undyed and dyed coir was analysed and the second order rate equation was observed to provide the best correlation of the experimental data. Adsorption isotherm models were developed. The best fit was obtained in the Langmuir model. When subjected to repeated adsorption-desorption cycles, with an intermediate step of mild sodium hydroxide treatment, both dyed and undyed coir retained its adsorptive capacity even after five cycles of reuse. (C) 2004 Society of Chemical Industry.