Development of In-Situ sensors for Nutrients in Marine Waters.

Altahan, Mahmoud Fatehy (2022) Development of In-Situ sensors for Nutrients in Marine Waters. Open Access (PhD/ Doctoral thesis), Christian-Albrechts-Universität, Kiel, Germany, 226 pp.

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Abstract

In particular, I focussed on the development, improvement, and deployment of autonomous analysers for on-site monitoring of nutrients that have shown promise for further application in field monitoring either on shore or in the water column (in-situ).Macronutrients include nitrate, nitrite, phosphate, and silicic acid. These macronutrients are important for primary production, and silicic acid is essential for the hard tissue of siliceous phytoplankton (e.g., diatoms). The importance of macronutrients for photosynthesis means that their supply rates have major implications for the functioning of phytoplankton communities, which are considered an carbon dioxide sink in the ocean. The analysis of macronutrients is still more difficult than physical parameters such as salinity and temperature or dissolved oxygen. In addition, analysis of macronutrients in a complex matrix such as seawater can be challenging because their concentrations are typically low, in the range from nanomolar to micromolar. This thesis reports on the development of an electrochemical approach for the determination of orthophosphate in estuarine and seawater, reporting the initial investigations of our technique with a further application in an automated analyser which uses a bipotentiostat approach to enhance data quality. In addition, the improvement of on-site determination of macronutrients with a long-term application in estuarine and coastal water is reported.

Document Type: Thesis (PhD/ Doctoral thesis)
Thesis Advisor: Achterberg, Eric P. and Sander, Sylvia
Keywords: Electrochemical Sensors; Spectrophotometry; Orthophosphate; Nitrate; Silicic acid; Wet-chemical sensors; Autonomous monitoring
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-CH Chemical Oceanography > FB2-CH Water column biogeochemistry
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-CH Chemical Oceanography
Main POF Topic: PT6: Marine Life
Date Deposited: 22 Dec 2022 10:16
Last Modified: 07 Feb 2024 15:48
URI: https://oceanrep.geomar.de/id/eprint/57521

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