Biochar-nanoparticle combinations enhance the biogeochemical recovery of a post-mining soil

• DOI: 10.1016/j.scitotenv.2024.172451
• Publication Date: 2024-04-18T02:03:57Z
• Authors: Rubén Forján; Manuel Arias-Estévez; José Luis R. Gallego; Erika Santos; Daniel Arenas-Lago
• Keywords: Biogeochemical Cycle; Soil carbon; Cation-exchange capacity

Here we addressed the capacity of distinct amendments to reduce arsenic (As), copper (Cu), selenium (Se) and zinc (Zn) associated risks improve biogeochemical functions post-mining soil. To this, examined nanoparticles (NPs) and/or biochar effects, combined with phytostabilization using Lolium perenne L. Soil samples were taken in a former metal mine surroundings. Ryegrass seeds sown pots containing different combinations NPs (zero-valent iron (nZVI) or hydroxyapatite (nH)) (0 2 %), (0, 3 5 %). Plants grown for 45 days plant yield element accumulation evaluated, also soil properties (element distribution within fractions, fertility, enzymatic activities microbiota functionality nutrient cycling) determined. Results showed biochar-treated had higher pH, much organic carbon (C) content than control NP-treated soils, it revealed increased labile C, total N, available P concentrations. treatment NP-biochar exchangeable non-acid cation concentrations reduced Na%, improved sodicity risk, ryegrass biomass. Enzymatic activities, particularly dehydrogenase glucosidase, upon addition biochar, this effect was fostered by NPs. Most treatments led significant reduction metal(loid)s contents biomass, mitigating contamination risks. The two similar effects many parameters, nH outperformed nZVI terms nutrients, C content, activities. On basis our results, biochar-NP use, specially nH, emerges as potential restoration strategy.