In Situ Use of Mining Substrates for Wetland Construction: Results of a Pilot Experiment

• Published in: Plants (Basel) 2024-04, Vol.13 (8), p.1161
• Main Authors: Hernández-Pérez, Carmen, Martínez-López, Salvadora, Martínez-Sánchez, María José, Martínez-Martínez, Lucia Belén, García-Lorenzo, María Luz, Perez Sirvent, Carmen
• Format: Article
• Language: English
• Subjects: Acid mine drainage; Alkalinity; Aquatic plants; Artificial wetlands; coastal areas; Constructed wetlands; Ecosystem services; Experiments; Flowers & plants; Heavy metals; Limestone; Macrophytes; Materials; Mine drainage; Mine wastes; Mineralogy; Mining; mining sites; Natural attenuation; Oxidation; Peat; Phytoremediation; Pilot projects; potentially toxic elements; Precipitation; Reclamation; Rhizosphere; Runoff; Scanning electron microscopy; Sediments; Sediments (Geology); Soil conservation; Soil management; Substrates; Topsoil; Toxicity; Water treatment; wetland; Wetlands
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants13081161

This paper evaluates an experimental wetland as part of a pilot soil reclamation project in a mining area. The wetland was constructed using materials of mining origin from the area; most reactive materials of acid pH were stabilised using limestone filler. The study selected macrophytes that are tolerant to potentially toxic elements (PTEs) and resistant to salinity, namely , , and . These macrophytes were then placed in pots containing substrates composed of different mixtures of topsoil, peat, and mining waste (black or yellow sand). A thorough analysis of the physicochemical and mineralogical characteristics of the materials included studies of PTE mobilisation. This study emphasises the significance of the rhizosphere in directing the transfer of PTEs to the plant and the correlation between the substrate and the development of plant defence mechanisms, such as the formation of Fe-plates. Scanning electron microscopy was used to highlight these aspects and validate the results of the analytical determinations. These wetlands can be proposed as a phytoremediation strategy for areas affected by mining and maritime influence. They are easy to construct and remain stable, providing important ecosystem services such as the natural attenuation of acid mine drainage, support for vegetation development and fauna, and a clean ecosystem.