Entrapped elemental selenium nanoparticles affect physicochemical properties of selenium fed activated sludge.
Selenite containing wastewaters can be treated in activated sludge systems, where the total selenium is removed from the wastewater by the formation of elemental selenium nanoparticles, which are trapped in the biomass. No studies have been carried out so far on the characterization of selenium fed activated sludge flocs, which is important for the development of this novel selenium removal process. This study showed that more than 94% of the trapped selenium in activated sludge flocs is in the form of elemental selenium, both as amorphous/monoclinic selenium nanospheres and trigonal selenium nanorods. The entrapment of the elemental selenium nanoparticles in the selenium fed activated sludge flocs leads to faster settling rates, higher hydrophilicity and poorer dewaterability compared to the control activated sludge (i.e., not fed with selenite). The selenium fed activated sludge showed a less negative surface charge density as compared to the control activated sludge. The presence of trapped elemental selenium nanoparticles further affected the spatial distribution of Al and Mg in the activated sludge flocs. This study demonstrated that the formation and subsequent trapping of elemental selenium nanoparticles in the activated sludge flocs affects their physicochemical properties.
UNESCO-IHE, Institute for Water Education, Westvest 7, 2611AX Delft, The Netherlands; Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454, Marne la Vallée, France. Electronic address: rohanjain.iitd@gmail.com.
Rohan
R
Jain
Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454, Marne la Vallée, France; Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - UPMC Univ Paris 06, UMR CNRS 7590, Muséum National d'Histoire Naturelle, IRD UMR 206, Paris, France.
Marina
M
Seder-Colomina
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany.
Norbert
N
Jordan
UNESCO-IHE, Institute for Water Education, Westvest 7, 2611AX Delft, The Netherlands.
Paolo
P
Dessi
Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - UPMC Univ Paris 06, UMR CNRS 7590, Muséum National d'Histoire Naturelle, IRD UMR 206, Paris, France.
Julie
J
Cosmidis
Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454, Marne la Vallée, France.
Eric D
ED
van Hullebusch
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany.
Stephan
S
Weiss
Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - UPMC Univ Paris 06, UMR CNRS 7590, Muséum National d'Histoire Naturelle, IRD UMR 206, Paris, France.
François
F
Farges
UNESCO-IHE, Institute for Water Education, Westvest 7, 2611AX Delft, The Netherlands.
Piet N L
PN
Lens
D053758:Nanoparticles / Q000032:analysis / Q000737:chemistry*; D012643:Selenium / Q000032:analysis / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*
D012722:Sewage; D012643:Selenium
Activated sludge; Nanoparticles; Physicochemical; Selenium; Settleability; Surface charge