Remediation potential of mining, agro-industrial, and urban wastes against acid mine drainage

Abstract

Acid mine drainage (AMD) poses serious consequences for human health and ecosystems. Novel strategies for its treatment involve the use of wastes. This paper evaluates the remediation potential of wastes from urban, mining and agro-industrial activities to address acidity and high concentrations of potentially toxic elements (PTE) in AMD. Samples of these waste products were spiked with an artificially prepared AMD, then pH, electrical conductivity (EC), and PTE concentrations in the leachates were measured. The artificial AMD obtained through oxidation of Aznalcóllar’s tailing showed an ultra-acid character (pH − 2.89 ± 0.03) and extreme high electrical conductivity (EC − 3.76 ± 0.14 dS m−1). Moreover, most PTE were above maximum regulatory levels in natural and irrigation waters. Wastes studied had a very high acid neutralising capacity, as well as a strong capacity to immobilise PTE. Inorganic wastes, together with vermicompost from pruning, reduced most PTE concentrations by over 95%, while organic wastes retained between 50 and 95%. Thus, a wide range of urban, mining, and agro-industrial wastes have a high potential to be used in the treatment of AMD. This study provides valuable input for the development of new eco-technologies based on the combination of wastes (eg. Technosols, permeable reactive barriers) to remediate degraded environments.

Technosols Derived from Mining, Urban, and Agro-Industrial Waste for the Remediation of Metal(loid)-Polluted Soils: A Microcosm Assay

“…Technosols were incubated for 2 months at room temperature (20-25 • C) with periodic watering and aeration (every 3 days), maintaining 70% of field capacity. The main physicochemical and biological characteristics of the amendments, as well as their metal(loid) retention capacity in simulated acid mine drainage, as analysed in [30], can be found in Tables S1 and S2, respectively. Polluted soil (PS), iron oxyhydroxide-rich sludge (IO), carbonated waste from peat extraction (CW), marble cutting and polishing sludge (MS), solid olive mill by-product (OL), composted sewage sludge (WS), vermicompost from pruning and gardening (VC).…”

Adsorption of Toxic Metals Using Hydrous Ferric Oxide Nanoparticles Embedded in Hybrid Ion-Exchange Resins

“…AMD is the acidic and metal-rich water that results from the oxidation of sulfide-containing minerals exposed during mining activities [ 1 , 2 ]. AMD can pollute nearby water resources, endangering the ecosystem and human health [ 3 , 4 ]. Heavy metals are persistent in the environment and can accumulate in soft tissues, disrupting the normal functioning of vital organs and systems [ 5 , 6 ].…”

Microbial community structure in an uranium-rich acid mine drainage site: implication for the biogeochemical release of uranium

“…Acid mine drainage (AMD) is the biggest environmental problem facing the global mining industry, characterized by strong acidity and high concentrations of sulfates and toxic metals, thereby posing a severe risk of environmental contamination in proximity to mining sites and presenting a persistent threat to ecosystems ( Acharya and Kharel, 2020 ; Aguilar-Garrido et al, 2023 ). It is produced through the oxidation of sulfide minerals (e.g., pyrite), and the total reaction process is as follows: FeS 2 + 3.5O 2 + H 2 O → Fe 2+ + 2SO 4 2− + 2H + ( Baker and Banfield, 2003 ).…”