Electrochemical Ocean Iron Fertilization: Coupled CFD and Experimental Approach to Controlled Iron Delivery

Rising atmospheric carbon dioxide (CO₂) levels necessitate innovative scalable solutions. Electrochemical ocean iron fertilization (EOIF) is a promising carbon sequestration method that releases bioavailable iron into seawater to stimulate phytoplankton growth, enhancing CO₂ uptake via photosynthesis. However, conventional approaches face challenges in regulating iron solubility and dosage. This study integrates EOIF with ocean alkalinity enhancement (OAE) to improve iron dissolution and ensure controlled release under oceanic conditions. The alkaline environment increases iron saturation limits, creating favorable conditions for phytoplankton proliferation. To optimize system performance, a computational fluid dynamics (CFD) model is developed to simulate electrochemical iron release. The model incorporates fluid flow, electrode geometry, electrolyte composition, and reaction kinetics, enabling time-resolved predictions of iron dispersion. Simulation results were used to refine system parameters, including electrode positioning and reactor configuration, to maintain biologically effective concentrations without reaching toxicity thresholds. Experimental validation is conducted using a custom-designed electrochemical system. Measured iron concentrations and phytoplankton growth trends align well with simulation predictions, confirming the system's effectiveness. The integrated CFD-experimental framework provides a reliable tool for guiding EOIF design and deployment. This work demonstrates the potential of EOIF-OAE systems for enhancing marine photosynthetic activity and atmospheric CO₂ removal. It also offers a valuable modeling and validation framework for the broader scientific community working on marine carbon dioxide removal and climate-resilient ocean technologies.