title: Removal of fluoroquinolone contaminants from environmental waters on sepiolite and its photo-induced regeneration.
abstract: Sepiolite is studied as sorbent for removal of Fluoroquinolone (FQ) contaminants from water. Marbofloxacin (MAR) and Enrofloxacin (ENR) were chosen as model FQs since they are the two most commonly employed veterinary FQs in livestock farming in northern Italy. Adsorption experiments on two sepiolites (SP-1 and SSE16) were carried out in tap water at pH 7.5 to better mimic real conditions. The sorption experimental data were fitted by Freundlich, Langmuir and S-Logistic1 models. The latter better described MAR and ENR adsorptions. Adsorption capacities of SP-1 and SSE16, respectively, were 132 mg g(-1) and 121 mg g(-1) for MAR, and 112 mg g(-1) and 93 mg g(-1) for ENR. X-ray powder diffraction, performed on clay samples enriched with each FQ and on the pristine clays, showed no substantial differences between the two sepiolites and evidenced no significant structural changes after FQs uptake, as also verified by infrared spectroscopy. This indicates that adsorption occurs only on the external surface of the mineral and not in the intracrystalline microporosity, likely due to the interaction between the FQ carboxylic group and the sepiolite surface. For the first time solid-state photodegradation of the adsorbed FQs was investigated for regenerating the sorbent. Results showed that the adsorbed drugs are effectively photodegraded by solar light, thus allowing sepiolite to be reused. The efficiency of this material for remediation of contaminated water was proved on ditch water, collected downstream a swine farm, containing some tens of ng L(-1) of MAR and ENR.
authors.affiliation: Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy. Electronic address: michela.sturini@unipv.it.
authors.forename: Michela
authors.initials: M
authors.lastname: Sturini
authors.affiliation: Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Speltini
authors.affiliation: Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Maraschi
authors.affiliation: Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Profumo
authors.affiliation: Department of Earth and Environmental Sciences, University of Pavia, via Ferrata 9, 27100 Pavia, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Tarantino
authors.affiliation: Department of Chemical and Earth Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy.
authors.forename: Alessandro F
authors.initials: AF
authors.lastname: Gualtieri
authors.affiliation: Department of Earth and Environmental Sciences, University of Pavia, via Ferrata 9, 27100 Pavia, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Zema
mesh_terms: D000327:Adsorption; D000818:Animals; D000077422:Enrofloxacin; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D024841:Fluoroquinolones / Q000737:chemistry*; D007558:Italy; D017633:Magnesium Silicates / Q000737:chemistry*; D010782:Photolysis; D013472:Sunlight; D013552:Swine; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D024841:Fluoroquinolones; D017633:Magnesium Silicates; D014874:Water Pollutants, Chemical; D000077422:Enrofloxacin; C080260:marbofloxacin; C001671:magnesium trisilicate
keywords: Adsorption; Emerging pollutants; Fluoroquinolones; Photodegradation; Remediation; Sepiolite