Assessing the impacts of sewage sludge amendment containing nano-TiO2 on tomato plants: A life cycle study

Mansi Bakshi , Clarisse Liné (1, 2) , Diana Bedolla , Ricardo José Stein , Ralf Kaegi (3) , Géraldine Sarret (4) , Ana Pradas del Real (4, 5) , Hiram Castillo-Michel (5) , P.C. Abhilash , Camille Larue (1)

1 LEFE - Laboratoire Ecologie Fonctionnelle et Environnement
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 EAWAG - Swiss Federal Insitute of Aquatic Science and Technology [Dübendorf]
4 ISTerre - Institut des Sciences de la Terre
5 ESRF - European Synchrotron Radiation Facility

Increasing evidence indicates the presence of engineered nanoparticles (ENPs) in sewage sludge derived from wastewater treatment. Land application of sewage sludge is, therefore, considered as an important pathway for ENP transfer to the environment. The aim of this work was to understand the effects of sewage sludge containing nano-TiO2 on plants (tomato) when used as an amendment in agricultural soil. We assessed developmental parameters for the entire plant life cycle along with metabolic and bio-macromolecule changes and titanium accumulation in plants. The results suggest that the sewage sludge amendment containing nano-TiO2 increased plant growth (142% leaf biomass, 102% fruit yield), without causing changes in biochemical responses, except for a 43% decrease in leaf tannin concentration. Changes in elemental concentrations (mainly Fe, B, P, Na, and Mn) of plant stem, leaves and, to a lesser extent fruits were observed. Fourier-transformed infrared analysis showed maximum changes in plant leaves (decrease in tannins and lignins and increase in carbohydrates) but no change in fruits. No significant Ti enrichment was detected in tomato fruits. In conclusion, we evidenced no acute toxicity to plants and no major implication for food safety after one plant life cycle exposure.

Domaines: Sciences de l'environnement; Environnement et Société

Mansi Bakshi, Clarisse Liné, Diana Bedolla, Ricardo José Stein, Ralf Kaegi, et al.. Assessing the impacts of sewage sludge amendment containing nano-TiO2 on tomato plants: A life cycle study. Journal of Hazardous Materials, 2019, 369, pp.191-198. ⟨10.1016/j.jhazmat.2019.02.036⟩. ⟨hal-02324977⟩