title: Adsorption of 2,4-Dichlorophenoxyacetic Acid from an Aqueous Solution on Fly Ash.
abstract: The adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) on fly ash was studied. The effects of adsorbent dose, contact time, pH, ionic strength, and temperature on the adsorption were investigated. Adsorption kinetic data were analyzed using pseudo-first and pseudo-second order models, and results showed that adsorption kinetics were better represented by the pseudo-second order model. Adsorption isotherms of 2,4-D on fly ash were analyzed using the Freundlich and Langmuir models. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicated that the adsorption process was spontaneous and endothermic. The negative values of ΔG° and the positive value of ΔH° indicate the spontaneous nature of 2,4-D adsorption on fly ash, and that the adsorption process was endothermic. Results showed that fly ash is an efficient, low-cost adsorbent for removal of 2,4-D from water.
authors.affiliation: Institute of Chemistry, Military University of Technology, 00-908 Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kuśmierek
authors.forename: Andrzej
authors.initials: A
authors.lastname: Świątkowski
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000302:isolation & purification*; D000327:Adsorption; D060729:Coal Ash / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D060729:Coal Ash; D014874:Water Pollutants, Chemical; D015084:2,4-Dichlorophenoxyacetic Acid