Sawdust--a green and economical sorbent for the removal of cadmium (II) ions.
The ability of sawdust (treated and untreated) waste, a waste material derived from the commercial processing of cedrus deodar wood for furniture production, to remove/preconcentrate Cd(II) ions from aqueous solution was determined. Sorption was found to be rapid (approximately 97% within 8 min). The binding of metal ions was found to be pH dependent, optimal sorption accruing at around pH 4-8. Potentiometric titrations of sawdust revealed two distinct pK(a) values, the first having the value similar to carboxylic groups (3.3-4.8) and second comparable with that of amines (8.53-10.2) with the densities 1.99 x 10(-4) and 7.94 x 10(-5), respectively. Retained Cd(II) ions were eluted with 5 ml of 0.1 mol l(-1) HCl. Detection limit of 0.016 microg ml(-1) was achieved with enrichment factors of 120. Recovery was quantitative using sample volume of 600 ml. The Langmuir and D-R isotherm equations were used to describe partitioning behavior for the system at different temperatures. Kinetic and thermodynamic behavior of sawdust for Cd(II) ions removal was also studied.
Memon
Saima Q
SQ
M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, Pakistan. msaima77@gmail.com
Memon
Najma
N
Shah
S W
SW
Khuhawar
M Y
MY
Bhanger
M I
MI
D000327:Adsorption; D002104:Cadmium / Q000032:analysis / Q000302:isolation & purification*; D002413:Cations, Divalent / Q000302:isolation & purification; D028203:Cedrus; D004785:Environmental Pollutants / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000302:isolation & purification; D011522:Protons; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors; D014867:Water / Q000737:chemistry; D018508:Water Purification / Q000191:economics*; D014934:Wood
D002413:Cations, Divalent; D004785:Environmental Pollutants; D008670:Metals; D011522:Protons; D002104:Cadmium; D014867:Water