The role of pesticides in stabilization of TiO2 nanoparticles in aquatic environments

Svetlana Ilina (1) , Patrick Ollivier (1) , Nicole Baran (1) , Danielle Slomberg (2, 3) , Nicolas Devau (1) , Anne Pariat (3, 2) , Nicole Sani-Kast (4) , Martin Scheringer (5, 4) , Jérôme Labille (3, 2)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence, France
3 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
4 IBT - Institute for Biomedical Engineering [ETH Zürich]
5 RECETOX / MUNI - Research Centre for Toxic Compounds in the Environment [Brno]

The influence of pesticides (glyphosate, aminomethylphosphonic acid (AMPA) and 2.4-D) on the surface charge and aggregation of pure TiO2 nanoparticles (NP; 5-30 nm; anatase and rutile) have been investigated in modeled water solutions. The dependence of the surface charge and the size distribution at upon the various factors (including surface chemistry of NP and pesticides, presence of mono- (Na+) and bi-valent (Ca2+) cations, pH value, and ionic strength (IS) of an aqueous solution) has been studied. The presence of glyphosate (5µg/L) affects rutile TiO2 NP (5 mg/L) stabilization in NaCl solution of IS=10-4M - 10-3M (>CCC) and in CaCl2 solution of IS =10-4M (>CCC) with pH=5 near the pH point of zero charge (PZC) (pHPZC=4.5). With adding of the glyphosate no changes in NP aggregation were observed in very high (IS= 10-1M) ionic strength solutions for rutile NP and in all studied conditions for anatase NP. No significant changes in NP aggregation were observed in the presence of AMPA and 2.4-D. Compared to mono-valent cations, bi-valent cations favored an increase in zeta potential at pH8 and no changes at pH5. These results show new evidences of the role of pesticides on the NP mobility in aquatic environments.

Keywords: nanoparticles; pesticides; stabilization; glyphosate

Domains: Environmental Sciences

Svetlana Ilina, Patrick Ollivier, Nicole Baran, Danielle Slomberg, Nicolas Devau, et al.. The role of pesticides in stabilization of TiO2 nanoparticles in aquatic environments. Goldschmidt 2016, Jun 2016, Yokohama, Japan. 2016. ⟨hal-01285033⟩