Core-shell material for the controlled release of low-molecular-weight organic acid (LMWOA) in ultramafic soil

Soils derived from ultramafic rocks contain naturally high concentrations of potentially toxic elements, such as nickel, chromium, manganese, and cobalt, and their extraction using conventional mining methods is associated with high costs and environmental impacts. In this context, agromining based on phytoextraction using hyperaccumulator species emerges as a sustainable alternative for metal recovery and soil remediation. In induced phytoextraction, the application of chelating agents increases metal bioavailability, promoting their uptake by plants. Although synthetic chelating agents, such as EDTA and DTPA, are highly efficient, their low biodegradability and the risk of metal leaching limit their use. As an alternative, low-molecular-weight organic acids (LMWOA) have been used because they are more biodegradable. However, their rapid degradation in soil and the immediate mobilization of metals reduce process efficiency and increase environmental risks, highlighting the need for strategies that promote their controlled release to better utilize the chelating agent.