Evaluation of adsorption potential of adsorbents: a case of uptake of cationic dyes.
Adsorption potential of a commercial activated carbon (FS300) has been evaluated for the uptake of cationic dyes namely methylene blue (MB) and rhodamine B (RB). Though, there are numerous studies in literature which report the sorption of MB (more than 40 studies) and RB (more than 10), however none of these use a common parameter to report the capacity of the sorbent. A protocol, based on the equilibrium dye concentration has been proposed to measure the sorption potential of a sorbent. The Langmuir model can very well describe the experimental equilibrium data for both dyes (coefficient of correlation > 0.999). MB (Qm = 312.5 mg g(-1)) is more adsorbable than the RB (Qm = 144.9 mg g(-1)). Molecular weight and chemical structure of dye molecules seem to affect the dye uptake. The effect of pH on dye uptake has also been evaluated by varyingpH from 3 to 11. Uptake of MB increases with pH, wherein RB removal decreases with pH. Dyes could not be desorbed either by distilled water (0.06 and 0.11% for MB and RB respectively), or by 0.1 NHCl (0.136 and 3.0% for MB and RB respectively) indicating, chemical adsorption type of adsorbent-adsorbate interactions.
Maurya
Nityanand Singh
NS
Environmental Engineering Laboratory, Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110 016, India.
Mittal
Atul Kumar
AK
Cornel
Peter
P
D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002412:Cations / Q000737:chemistry / Q000302:isolation & purification; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D008751:Methylene Blue / Q000737:chemistry / Q000302:isolation & purification; D008956:Models, Chemical; D012235:Rhodamines / Q000737:chemistry / Q000302:isolation & purification; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D002412:Cations; D004396:Coloring Agents; D012235:Rhodamines; D014874:Water Pollutants, Chemical; D002244:Carbon; C029773:rhodamine B; D008751:Methylene Blue