title: Composition and structural effects on the adsorption of ionic liquids onto activated carbon.
abstract: The applications and variety of ionic liquids (ILs) have increased during the last few years, and their use at a large scale will require their removal/recovery from wastewater streams. Adsorption on activated carbons (ACs) has been recently proposed for this aim and this work presents a systematic analysis of the influence of the IL chemical structures (cation side chain, head group, anion type and the presence of functional groups) on their adsorption onto commercial AC from water solution. Here, the adsorption of 21 new ILs, which include imidazolium-, pyridinium-, pyrrolidinium-, piperidinium-, phosphonium- and ammonium-based cations and different hydrophobic and hydrophilic anions, has been experimentally measured. This contribution allows an expansion of the range of IL compounds studied in previous works, and permits a better understanding of the influence of the IL structures through the adsorption on AC. In addition, the COSMO-RS method was used to analyze the measured adsorption isotherms, allowing the understanding of the role of the cationic and anionic structures in the adsorption process, in terms of the different interactions between the IL compound and AC surface/water solvent. The results of this work provide new insights for the development of adsorption as an effective operation to remove/recover ILs with very different chemical nature from water solution.
authors.affiliation: Sección de Ingeniería Química (Departamento de Química Física Aplicada), Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain. jesus.lemus@uam
authors.forename: Jesús
authors.initials: J
authors.lastname: Lemus
authors.forename: Catarina M S S
authors.initials: CM
authors.lastname: Neves
authors.forename: Carlos F C
authors.initials: CF
authors.lastname: Marques
authors.forename: Mara G
authors.initials: MG
authors.lastname: Freire
authors.forename: João A P
authors.initials: JA
authors.lastname: Coutinho
authors.forename: Jose
authors.initials: J
authors.lastname: Palomar
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D052578:Ionic Liquids / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D052578:Ionic Liquids; D014874:Water Pollutants, Chemical; D002606:Charcoal