Novel field trial for ocean alkalinity enhancement using electrochemically derived aqueous alkalinity

作者：Allison M. Savoie, Mallory Ringham, Carolina Torres Sanchez, Brendan R. Carter, S. M. Dougherty, Richard A. Feely, Dave Hegeman, Julian Herndon, Tarang Khangaonkar, J.C. Loretz, Tyson Minck, Todd Pelman, Lakshitha Premathilake, Chinmayee V. Subban, Jesse Vance, Nicholas Ward · 发表于：Frontiers in Environmental Engineering · 年份：2025 · DOI：10.3389/fenve.2025.1641277 · 被引用次数：11 · 研究领域：Gas Sensing Nanomaterials and Sensors、Ocean Acidification Effects and Responses、Analytical Chemistry and Sensors

Ocean alkalinity enhancement is a proposed method of marine carbon dioxide removal that enhances the ocean’s uptake of atmospheric carbon dioxide (CO 2 ) and converts it to dissolved bicarbonate for long-term ocean storage. This method of marine carbon dioxide removal has been gaining attention for its potential to durably (10,000+ years) store large amounts of CO 2 (Gt + where 1 Gt = 1 × 10 9 tons), while potentially ameliorating acidification in the vicinity of the alkalinity release. This study focuses on a novel release of electrochemically derived aqueous alkalinity into Sequim Bay, WA, through a previously established wastewater treatment plant (WWTP). This research was made possible through the collaboration of industry, academic, and federal partners, which enabled the establishment of an Ebb Carbon electrochemical mCDR system at the Pacific Northwest National Laboratory in Sequim, WA, for ocean alkalinity enhancement field trials. During these field trials, pH was measured across the WWTP system from the initial alkalinity dosing, throughout the WWTP, and at the outfall. We use the NBS scale for pH throughout this study as it is the scale used in discharge permit limits specified for WWTP and NPDES regulation and compliance monitoring. The background pH NBS of Sequim Bay seawater was between 7.5 and 7.7 for the November and February field tests. The mixing tank’s pH NBS was raised to the maximum value permitted for the WWTP (9.0) and maintained across the system (±0....