סמינר מחלקתי בזום מאת גרא רודניק - דוקטורנט של פרופ' אבינועם רבינוביץ בנושא: ניהול מילוי אקוויפר עם מי ים מותפלים: ערבוב של אי ודאות והעשרה טבעית של מגנזיום

Manage Aquifer Recharge with Desalinated Seawater: Mixing Uncertainty and Natural Magnesium Enrichment

Seminar by German RUDNIK

Abstract:

Desalinated seawater is increasingly used as a drinking-water source, but it lacks important minerals such as magnesium. At the Menashe Streams managed aquifer recharge site in Israel, surplus desalinated seawater has been infiltrated into the aquifer since 2015, together with natural winter stream runoff. This setting provides a rare opportunity to study the fate of desalinated water in an unconfined sandy aquifer.

Using field observations, stable water isotopes, stochastic flow modelling, and transport modelling, this research examines two connected questions. First, how reliably can we predict the underground mixing of desalinated seawater and natural runoff? The results show that future rainfall and recharge variability can create larger uncertainty than the interpreted geological structure of the aquifer itself (Rudnik et al., 2022). Second, can subsurface passage naturally enrich desalinated seawater with magnesium? Eight years of field observations and reactive transport simulations show that desalinated seawater gains magnesium as it moves through the subsurface, mainly through ion exchange. Long-term simulations suggest that the subsurface can add about 5 mg/L of magnesium to the desalinated water, making subsurface passage a potentially useful, low-cost supplementary strategy for improving the quality of desalinated seawater (Rudnik et al., 2026).
In addition, initial results from a large scale tracer test in Shafdan will be presented, where we attempt to quantify residence time of recharged secondary effluents in the subsurface.

Bio:

German RUdink is at his 7th (and final) -year PhD researcher in Mechanical Engineering at Tel Aviv University, in Dr. Avinoam Rabinovich group under co-supervision of Dr. Daniel Kurtzman from Volcani. He is also a civil engineer, and a freelance hydrologist, with a master’s degree in Hydroinformatics. The research work that he will present summarises 2/3 of his PhD research and combines field observations with stochastic numerical modelling of flow, transport and chemical reactions of desalinated seawater recharged into Nahaley-Menashe managed aquifer recharge site.

Seminar Zoom link: https://tau-ac-il.zoom.us/j/82518539287

Linkdin https://www.linkedin.com/in/german-rudnik/

Google Scholar https://scholar.google.com/citations?user=dSyswIgAAAAJ&hl=en