Higher Inorganic CO 2 Removal Despite Slower Weathering in an Enhanced Weathering Experiment With Steel Slags and Basalt

作者：Laura Steinwidder, Lucilla Boito, Anthony de Schutter, Patrick Frings, Nina Miladinović, Harun Niron, Jet Rijnders, Jasper Roussard, Karel Van Acker, Tom Van Gerven, Arthur Vienne, Ponnapat Watjanatepin, Sara Vicca · 发表于：Global Change Biology · 年份：2026 · DOI：10.1111/gcb.70666 · 被引用次数：3 · 研究领域：CO2 Sequestration and Geologic Interactions、Concrete and Cement Materials Research、Microbial Applications in Construction Materials

ABSTRACT The natural process of silicate weathering has inspired two CO 2 removal technologies: enhanced weathering and mineral carbonation. Here, in a 15‐month mesocosm experiment, both approaches were combined, with the aim of maximising CO 2 removal. To do so, pre‐carbonated steel slags (basic oxygen furnace (BOF) and argon oxygen decarburisation (AOD) slag) with mineral carbonation rates ranging from 0.04 to 0.13 t CO 2 /t rock were applied to soil planted with maize. Other treatments included uncarbonated slags and basalt for comparison. Aside from the commonly assessed leachate and soil solid carbonate pool, which contribute to inorganic CO 2 removal, also other soil pools (plant, exchangeable, (hydr)oxide, SOM) not directly linked to CO 2 removal were assessed. These alternative sinks are key to better understand the low inorganic CO 2 removal efficiencies reported in many experiments. Indeed, also in this experiment, the realised inorganic CO 2 removal of enhanced weathering remained low in all treatments (< 0.014 t CO 2 /t rock), except for the highest carbonated slag treatment, which removed slightly more CO 2 (0.04 t CO 2 /t rock). Thus, with a high degree of prior mineral carbonation, the inorganic CO 2 removal during enhanced weathering was increased. This was the case even though carbonated slags weathered slower. These results demonstrate that active weathering does not necessarily imply high inorganic CO 2 removal. While slags weathered almost entirely afte...