Alkalinity addition to coastal seawater in conjunction with green hydrogen generation: chemical and biological impacts and verification of CO2 uptake.

The proposed research will assess the efficacy, impacts and benefits of adding hydroxide to seawater, examining how it affects ocean chemistry, CO2 uptake, and selected marine biota. The research questions arise in connection with Planetary Hydrogen's innovative low-energy, cost-effective process which uses renewable energy to electrolyze a saline solution, producing hydroxide ions and hydrogen gas. Adding the hydroxide to the surface ocean will capture atmospheric CO2 and convert it to dissolved bicarbonate, mimicking natural weathering reactions that have created the ocean's massive bicarbonate and carbonate ion reservoir. The added alkalinity also can help reverse ocean acidification caused by CO2 uptake, benefiting acid-sensitive organisms that include commercially important shellfish. The project will involve laboratory experimentation to confirm theoretical understanding of the chemical response to alkalinity addition. Experiments with coastal phytoplankton and with oyster larve in a commercial hatchery will examine biological responses.The project will also involve field experiments and modelling in order to develop and test vmonitoring approaches that can be used to verify that the alkalinity addition results in the expected amount of atmospheric CO2 uptake. Overall, the results will contribute to the development of Planetary Hydrogen's novel co-production process, which generates hydroxide and clean hydrogen (H2) - a valuable fuel and feedstock. It will provide key information to guide establishment of Planetary Hydrogen's first pilot plant in Nova Scotia.Our multidisciplinary partnership brings together Dalhousie University researchers, Planetary Hydrogen Inc., Fisheries and Oceans Canada scientists, the ClimateWorks Foundation, the Thistledown Foundation, and a commercial oyster hatchery, L'Étang Ruisseau Bar. The team includes experts from Germany's GEOMAR Helmholtz Centre for Ocean Research Kiel and the Scripps Institution of Oceanography (USA).