Zacharias (2026): Repurposing enhanced rock weathering for brownfield cleanup: a practical carbonate–silicate remineralization method for stabilizing cationic metals in shallow soils
Quinn Zacharias, IN: EarthArXiv, https://doi.org/10.31223/X53F5Q
Brownfield, mining-impacted, urban fill, and legacy agricultural sites often contain cationic metals concentrated in shallow soil horizons, where they sustain direct-contact, dust, and leaching risk and can complicate redevelopment. This paper reframes enhanced rock weathering (ERW), originally advanced for carbon dioxide removal, as a practical remineralization approach for immobilizing cationic metals in soil. The proposed method is not simply another mineral amendment. It uses controlled carbonate–silicate blends to accelerate soil-aging processes, acid neutralization, increased negative surface charge, Ca and Mg occupation of exchange sites, hydrolysis, sorption, and secondary Fe–Al mineral formation that shift metals from labile and leachable pools toward less mobile forms. The framework is grounded in a watershed-scale Vermont field deployment of low-Ni, Fe–Al-rich basalt and in prior liming, wollastonite, and ERW literature. Across these lines of evidence, silicate remineralization behaves as a slow-release liming system, hydrologically connected receiving zones can show strong buffering signatures, and metal lability can decline where alkalinity and base cations accumulate.