title: Evaluation of adsorption potential of adsorbents: a case of uptake of cationic dyes.
abstract: 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.
authors.affiliation: Environmental Engineering Laboratory, Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110 016, India.
authors.forename: Nityanand Singh
authors.initials: NS
authors.lastname: Maurya
authors.forename: Atul Kumar
authors.initials: AK
authors.lastname: Mittal
authors.forename: Peter
authors.initials: P
authors.lastname: Cornel
mesh_terms: 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*
chemical_list: D002412:Cations; D004396:Coloring Agents; D012235:Rhodamines; D014874:Water Pollutants, Chemical; D002244:Carbon; C029773:rhodamine B; D008751:Methylene Blue