Page 12 - tech fest 2025 ב״ש חוברת תקצירים

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The Influence of Flow Rate on the Sensitivity of the Electrochemical Sensor for Determining Lead Ion Concentration in Solution
ChE-A-05
May Ben Simon; maybensimon5@gmail.com
Advisors: Prof. Ariela Burg1, Dr. Inna Levitsky1 1SCE - Shamoon College of Engineering, Be’er-Sheva
Treatments for reducing heavy metal concentrations in wastewater are crucial for maintaining environmental health. Accurate identification of lead ions in solutions is essential for effective water contamination monitoring. In this study, a flow system was developed to investigate the effect of flow on lead concentration determination using an electrochemical sensor. This analysis was conducted using the square wave voltammetry (SWV) method, which enables sensitive and precise heavy metal detection. The developed system successfully detected lead concentrations in the low ppm range: 0.25-1.25 ppm while evaluating the influence of flow conditions within a range of 20 L/h to 100 L/h. These results indicate that lead can be detected in water at ppm concentrations without significant interference by the flow rate.
Keywords: electrochemical sensor, flow conditions, heavy metal contamination, lead ion detection, SWV
Monitoring Caffeine Release from Polysaccharide Hydrogel Beads
ChE-A-06
Adi Abutbul Zana; adida1289@gmail.com
Advisors: Prof. Oshrat Ontman1, Prof. Adi Wolfson1 1SCE - Shamoon College of Engineering, Be’er-Sheva
‘Controlled release’ (CR) is a slow and sustained release of a specific substance to maintain its concentration level over time. Hydrogels made of crosslinked polymers are ideal for CR systems. This study investigated the CR of caffeine at different concentrations (1000-6000 ppm) from hydrogels prepared by crosslinking renewable polysaccharides from algae (alginate and iota and kappa carrageenans) with chitosan (medium molecular weight) and iron ions (0.1M). It was found that all the tested polysaccharides exhibited a similar caffeine release pattern, with the release process lasting up to 30 minutes. Furthermore, higher caffeine loading during preparation led to higher final concentrations and the use of a 2%W/V polysaccharide solution instead of 1%W/V resulted in better CR.
Keywords: algae, caffeine, chitosan, controlled release, HPLC, polysaccharides