Accéder directement au contenu Accéder directement à la navigation
Communication dans un congrès

Man made water cycles: Isotope tracing of desalinated seawater through water supply, sewage and groundwater

Abstract : Non-conventional water resources like desalinated water and treated sewage play today a key role in the water balance of many developed countries in arid and semi-arid regions. The worldwide capacity of desalination is expected to double within ten years to reach 62 Mm3/d in 2015 [1]. This massive arrival of "man-made" fresh water in the water cycle is expected to change geochemical and isotope characteristics of surface and groundwater. A pilot study in 2008 [2] has shown the highly specific isotope signatures of reverse osmosis (RO) desalinated seawater. Our current study presents isotope data (B, H+OH2O, S+OSO4) on the largest system of soil-aquifer treatment (SAT) in the Middle East - the Shafdan site, Israel - where 130 Mm3/Y of treated wastewater from the greater Tel Aviv region are infiltrated through ponds into the sandy Mediterranean Coastal Aquifer, recovered and then transported 70 km further to the South for unrestricted irrigation in the Negev desert. In Sept. 2010 and Feb. 2011, we analysed treated wastewater before infiltration, together with groundwaters at different distances from the infiltration ponds, as well as samples from the Tel Aviv drinking water supply and the product waters from two RO desalination plants. B isotopes of sewage show a siginficant shift from 1994 with a delta11B of +9.7 ±2.8‰ vs. NBS951 [3] to 2010-11 with + 40.4 ±0.7‰ (n=5). This shift is explained with (1) a change in legislation lowering considerably the perborate contents in washing powders (1999-2008) and (2) the massive arrival of desalinated seawater in the drinking water supply (delta11B of 53±3‰, [2]) since 2007. The breakthrough of this new boron signature has not yet been observed in the aquifer, not even for the wells closest to the infiltration ponds and no significant shift was observed between the two campaigns. This can be due to temporary sorption on clays leading to an important delay of B with respect to water [4] inducing a highly non-conservative behaviour. delta2H and delta18OH2O in wastewater and groundwater can be quantitatively explained by the different components of regional water supply, including the new desalination permeate. delta34S and delta18O of sulphates in wastewater, observed in the vicinity of the infiltration pond, are very different from desalinated seawater, the latter very depleted in SO42-, as sewage sulphate is dominated by other sources. This study reveals the usefulness of multi-isotope tracing for elucidating the mixing components and pathways of water and solutes in a nearly completely artificial regional water cycle. [1] Fritzmann et al. (2007) Desalination 216, 1-76. [2] Kloppmann et al. (2008) Environ. Sci. Technol. 42, 4723-4731. [3] Venghosh et al. (1994) Environ. Sci. Technol. 28, 1968-1974.
Liste complète des métadonnées

https://hal-brgm.archives-ouvertes.fr/hal-00685043
Contributeur : Wolfram Kloppmann <>
Soumis le : mardi 3 avril 2012 - 18:48:31
Dernière modification le : lundi 11 mai 2020 - 16:21:59

Identifiants

  • HAL Id : hal-00685043, version 1

Collections

Citation

Wolfram Kloppmann, Ido Negev, Joseph Guttman, Marie Pettenati, Catherine Guerrot, et al.. Man made water cycles: Isotope tracing of desalinated seawater through water supply, sewage and groundwater. Goldschmidt Conference 2012, Jun 2012, Montréal, Canada. ⟨hal-00685043⟩

Partager

Métriques

Consultations de la notice

382