title: Functionalized iron oxide/SBA-15 sorbent: investigation of adsorption performance towards glyphosate herbicide.
abstract: Glyphosate is a worldwide-used herbicide occurring in many monitoring campaigns. Efficient technologies are currently unavailable for glyphosate removal from waters. In this work, a SBA-15 mesoporous silica-based material (Fe-NH2-SBA-15) was synthesized and studied for the adsorption of glyphosate from waters. In order to promote specific interactions between the sorbent and glyphosate via phosphoric group, iron oxide nanoparticles were encapsulated and a surface functionalization with (3-aminopropyl)triethoxysilane was accomplished. The adsorption of glyphosate on Fe-NH2-SBA-15 was investigated as a function of (i) pH, (ii) ionic strength (I), and (iii) adsorbate to adsorbent ratio (C), using a two-level, three-factor experimental design. The experimental design allowed for understanding the effect of the abovementioned variables and for proposing experimental conditions for quantitative removal (pH = 2.1, I = 1⋅10-2M and C = 0.35) under both batch and dynamic conditions. Interaction mechanism between glyphosate and Fe-NH2-SBA-15 sorbent was elucidated by studying the adsorption behavior of sorbents derived from the intermediate stages of synthesis and by desorption tests. Fe-NH2-SBA-15 sorbent can be quantitatively regenerated by 12.5 mM NaOH, and can be reused at least for five adsorption/desorption cycles. Quantitative removal of glyphosate from inlet and effluent wastewaters from a wastewater treatment plant is shown.
authors: Department of Chemistry, University of Torino, via P. Giuria 5, 10125, Torino, Italy.
authors: Luca
authors: L
authors: Rivoira
authors: Department of Chemistry, University of Torino, via P. Giuria 5, 10125, Torino, Italy.
authors: Marta
authors: M
authors: Appendini
authors: Department of Applied Science and Technology, Polytechnic of Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy.
authors: Sonia
authors: S
authors: Fiorilli
authors: Department of Applied Science and Technology, Polytechnic of Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy.
authors: Barbara
authors: B
authors: Onida
authors: Department of Chemistry, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.
authors: Massimo
authors: M
authors: Del Bubba
authors: Department of Chemistry, University of Torino, via P. Giuria 5, 10125, Torino, Italy. mariaconcetta.bruzzoniti@unito.it.
authors: Maria Concetta
authors: http://orcid.org/0000-0002-9144-9254
authors: MC
authors: Bruzzoniti
mesh_terms: D000327:Adsorption; D005290:Ferric Compounds / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D006540:Herbicides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D009994:Osmolar Concentration; D012822:Silicon Dioxide / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*; D000097797:Glyphosate
chemical_list: D005290:Ferric Compounds; D005998:Glycine; D006540:Herbicides; D012822:Silicon Dioxide; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C509969:SBA-15; C000499:ferric oxide
keywords: Functionalized mesoporous silica; Glyphosate adsorption; Iron oxide nanoparticles; Regeneration; Reuse; Wastewaters