title: Effect of central metal ions of analogous metal-organic frameworks on adsorption of organoarsenic compounds from water: plausible mechanism of adsorption and water purification.
abstract: The adsorptive removal of organoarsenic compounds such as p-arsanilic acid (ASA) and roxarsone (ROX) from water using metal-organic frameworks (MOFs) has been investigated for the first time. A MOF, iron benzenetricarboxylate (also called MIL-100-Fe) exhibits a much higher adsorption capacity for ASA and ROX than activated carbon, zeolite (HY), goethite, and other MOFs. The adsorption of ASA and ROX over MIL-100-Fe is also much more rapid than that over activated carbon. Moreover, the used MIL-100-Fe can be recycled by simply washing with acidic ethanol. Therefore, it is determined that a MOF such as MIL-100-Fe can be used to remove organoarsenic compounds from contaminated water because of its high adsorption capacity, rapid adsorption, and ready regeneration. Moreover, only one of three analogous MIL-100 species (MIL-100-Fe, rather than MIL-100-Al or MIL-100-Cr) can effectively remove the organoarsenic compounds. This selective and high adsorption over MIL-100-Fe, different from other analogous MIL-100 species, can be explained (through calculations) by the facile desorption of water from MIL-100-Fe as well as the large (absolute value) replacement energy (difference between the adsorption energies of the organoarsenic compounds and water) exhibited by MIL-100-Fe. A plausible adsorption/desorption mechanism is proposed based on the surface charge of the MOFs, FTIR results, calculations, and the reactivation results with respect to the solvents used in the experiments.
authors.affiliation: Department of Chemistry and Green-Nano Materials Research Centre, Kyungpook National University, Daegu 702-701 (Republic of Korea), Fax: (+82) 53-950-6330.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Jun
authors.forename: Minman
authors.initials: M
authors.lastname: Tong
authors.forename: Beom K
authors.initials: BK
authors.lastname: Jung
authors.forename: Zubair
authors.initials: Z
authors.lastname: Hasan
authors.forename: Chongli
authors.initials: C
authors.lastname: Zhong
authors.forename: Sung Hwa
authors.initials: SH
authors.lastname: Jhung
mesh_terms: D000327:Adsorption; D001147:Arsanilic Acid / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D000073396:Metal-Organic Frameworks; D009942:Organometallic Compounds / Q000737:chemistry*; D012406:Roxarsone / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D056831:Coordination Complexes; D007477:Ions; C000589635:MIL-101; D000073396:Metal-Organic Frameworks; D009942:Organometallic Compounds; D014874:Water Pollutants, Chemical; D007501:Iron; D012406:Roxarsone; D001147:Arsanilic Acid
keywords: adsorption; arsenic; iron; metal-organic frameworks; water purification