title: Simple and green technique for sequestration and concentration of silver nanoparticles by polysaccharides immobilized on glass beads in aqueous media.
abstract: BACKGROUND
  Engineered nanoparticles have unique properties compared to bulk materials and their commercial uses growing rapidly. They represent a potential risk for environment and health and could be eventually released in water. Silver nanoparticles (Ag NP) are applied in various products and are well-known for their antibacterial properties. Nowadays, pre-concentration and separation methods for Ag NP possess some limitations. Here, we present a simple, green method to sequestrate and concentrate Ag NP from different aqueous media.
  
  
  RESULTS
  Supported polysaccharides on glass beads synthesized in water by a single step reaction show high sequestration capacity of citrate-coated Ag NP in aqueous media. Supported polysaccharides were characterized by infrared spectroscopy, scanning electron microscopy (SEM) and elemental analysis. Sequestration of 83.0 % of Ag NP was attained from a 20 μg.L(-1) aqueous solution with supported chitosan in water whereas supported 2-hydroxyethylcellulose (HEC) reached 64.0 % in synthetic seawater in 2 h. The influence of polymer/glass beads ratio and molecular weight of polysaccharides was also studied. The effect of the salinity and humic acids on sequestration of Ag NP was investigated. Supported polymers have shown high performance for sequestration of ionic silver. Sequestration of 82.5 % and 80.8 % were obtained from a 60 μg.L(-1) silver ion (as nitrate salt) with supported HEC and chitosan, respectively. Sequestrated Ag NP was characterized with transmission electron microscopy (TEM) where images showed Ag NP with unchanged size and shape.
  
  
  CONCLUSIONS
  This sequestration method, involving green synthesis, allows efficient concentration and characterization of Ag NP from different aqueous media. This simple and fast method is a potential sustainable technique for elimination of Ag NP and ionic silver from waste waters and waters at different salinities.
authors.affiliation: Département de Biologie, chimie et géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, QC G5L 3A1 Canada.
authors.forename: Alaeddine
authors.initials: A
authors.lastname: Kibeche
authors.affiliation: Département de Biologie, chimie et géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, QC G5L 3A1 Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Dionne
authors.affiliation: Département de Biologie, chimie et géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, QC G5L 3A1 Canada.
authors.forename: Roxanne
authors.initials: R
authors.lastname: Brion-Roby
authors.affiliation: Centre Saint-Laurent, Environment Canada, 105 McGill st., 7th floor, Montreal, QC H2Y 2E7 Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Gagnon
authors.affiliation: Département de Biologie, chimie et géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, QC G5L 3A1 Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gagnon
keywords: 2-hydroxyethylcellulose; Chitosan; Glass beads; Nanoparticles; Polysaccharides; Silver; Supported polymers