High-resolution temporal monitoring of rare earth elements in acidic drainages from an abandoned sulphide mine (iberian pyrite belt, Spain).

Rare earth elements (REE) are strategic elements due to their economic importance. However, the studies dedicated to the distribution and behaviour of REE in aquatic systems have been scarce until a few decades ago. This work studies the seasonal variations of REE concentrations in acid mine drainage (AMD) affected water courses and the factors controlling their mobility under different hydrological conditions.

Wildfire effects on the hydrogeochemistry of a river severely polluted by acid mine drainage.

This study evaluates for the first time the impact of a large wildfire on the hydrogeochemistry of a deeply AMD-affected river at the beginning of the wet season. To accomplish this, a high-resolution water monitoring campaign was performed within the basin coinciding with the first rainfalls after summer. Unlike similar events recorded in AMD-affected areas, where dramatic increases in most dissolved element concentrations, and decreases in pH values are observed as a result of evaporitic salts flushing and the transport of sulfide oxidation products from mine sites, a slight increase in pH values (from 2.

Environmental management and potential valorization of wastes generated in passive treatments of fertilizer industry effluents.

A phosphogypsum stack located in SW Spain releases highly acidic and contaminated leachates to the surrounding estuarine environment. Column experiments, based on a mixture of an alkaline reagent (i.e.

Design and optimization of sustainable passive treatment systems for phosphogypsum leachates in an orphan disposal site.

The optimization of the dispersed alkaline substrate (DAS) technology was investigated to achieve the treatment of highly acidic and polluted effluents from a phosphogypsum pile in an orphan site of SW Spain. This phosphogypsum disposal area is located on the Tinto river marsh soils, where it acts as a source of pollution for the estuarine environment, releasing high concentrations of metal(loid)s and radionuclides, which degrade the surrounding waters. The methodology consists of flowing the leachates through columns loaded with a combination of a fine-grained alkaline reagent scattered in a non-reactive matrix to raise the water pH while decreasing the solubility of dissolved contaminants.

Metal partitioning and speciation in a mining-impacted estuary by traditional and passive sampling methods.

This study deals with the metal partitioning and bioavailability of metal/loids in the estuary Ria of Huelva (SW Spain) which is strongly affected by historical mining and industrial activities. To address this issue, traditional (i.e.

Causes and impacts of a mine water spill from an acidic pit lake (Iberian Pyrite Belt).

In May 2017, a spill from La Zarza pit lake (SW Spain) resulted in the release of approximately 270,000 m of extremely acidic waters to the Odiel River. Around 780 × 10 kg of Fe, 170 × 10 kg of Al, 2.15 × 10 kg of As and high amounts of other trace metals and metalloids were spilled.

Assessment of metals mobility during the alkaline treatment of highly acid phosphogypsum leachates.

This research evaluates the feasibility of an alkaline treatment system for highly acid leachates from a phosphogypsum stack located in an estuarine environment degraded by such pollution. The presented methodology consists of the addition of a Ca(OH) solution to the different types of phosphogypsum-related acidic leachates with the aim to increase their pH and subsequently, to provoke the precipitation and immobilization of the dissolved contaminants. In fact, phosphates and fluorides reached removal of 100% and 90%, respectively.