Removal of chromium (III) by using coal as adsorbent.
The adsorption of Cr(III) by two different coal varieties from Lakhra and Thar coalfields (Pakistan) have been studied in batch mode. The effect of adsorbent dose, pH, contact time and agitation speed on the adsorption of Cr(III) by both the coals were investigated. Adsorption equilibrium was achieved in 40-50 min. The Langmuir, Freundlich and Temkin adsorption isotherms were used to elucidate the observed sorption phenomena. The maximum Cr(III) removal was 2.61 mg of Cr(III) per gram of LC (Lakhra coal) and 2.55 mg of Cr(III) per gram of TC (Thar coal) as evaluated from Langmuir isotherm. The heat of sorption was in the range 3.75-3.87 kJ/mol as evaluated from Temkin isotherm. Best results were obtained at pH>5. It is proposed that low rank coals of Pakistan can be used for removal of toxic metals like Cr(III) from industrial effluents/waste waters.
Anwar
Jamil
J
Institute of Chemistry, University of the Punjab, Lahore 54590, Pakistan.
Shafique
Umer
U
Salman
Muhammad
M
Waheed-uz-Zaman
Anwar
Shafique
S
Anzano
Jesús M
JM
D000327:Adsorption; D002857:Chromium / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification*; D003031:Coal; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007477:Ions; D008670:Metals / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D003031:Coal; D007220:Industrial Waste; D007477:Ions; D008670:Metals; D014874:Water Pollutants, Chemical; D002857:Chromium