pyrite

Managed aquifer recharge (MAR) is an increasingly used water management technique that enhances water availability while commonly generating water quality benefits. However, MAR activities may also trigger adverse geochemical reactions, especially during the injection of oxidant-enriched waters into reducing aquifers. Where this occurs, the environmental risks and the viability of mitigating them must be well understood. Here, we develop a rigorous approach for assessing and managing the risks from MAR-induced metal mobilization...

Pyrite is widely distributed in lacustrine shales and has become a research focus in unconventional oil and gas exploration. Pyrite morphology is useful for identifying different types of organic matter and assessing shale oil enrichment in organic-rich shale. Abundant pyrite is developed in the source rocks from the Chang 7 Member of the Yanchang Formation in the Ordos Basin, NW China. However, the relationship between different pyrite types and the differential enrichment of shale oil still needs to be clarified...

The possibility of selective Cu and Zn leaching from the sample of old pyrite tailings, which is one of the most widespread types of solid waste forming during non-ferrous metal production, using sulfuric acid solutions and water was studied. It was shown that water leaching provided selective extraction of Cu and Zn and comparatively low iron ion extraction. At the same time, acid leaching provided the obtainment of pregnant solutions with high ferric ion concentration, which can be used for oxidative leaching of substandard copper concentrates...

The thorough redox alteration of a lava flow is an undescribed feature in intraplate basaltic provinces. The Early Cretaceous (134.5 Ma) Paraná Province displays that alteration in the major Muralha Flow. This oxidized and reduced flow from the southern part of the province was studied with satellite images, field surveying, petrography, and published whole rock geochemistry. The 100 x 100 km flow from the Cuesta de Haedo presents two hydrothermal tiers - lower Tier 1 is gray to white, upper Tier 2 is red...

Acid mine drainage (AMD) induced by pyrite oxidation is a notorious and serious environmental problem, but the management of AMD in an economical and environmentally friendly way remains challenging. Here, lignin, a natural polymer and abundant waste, was employed as both a bactericide and passivator to prevent AMD formation. The addition of lignin to a mimic AMD formation system inoculated with Acidithiobacillus ferrooxidans at a lignin-to-pyrite weight ratio of 2.5: 10 reduced the combined abiotic and biotic oxidation of pyrite by 68...

Arsenopyrite and pyrite often coexist in metal deposits and tailings, thus simultaneous bioleaching of both sulfides has economic (as well as environmental) significance. Important targets in bio-oxidation operations are high solubilization rates and minimized accumulation of Fe(III)/As-bearing secondary products. This study investigated the role of pyrite bioleaching in the enhancement of arsenopyrite dissolution. At a pyrite to arsenopyrite mass ratio of 1:1, 93.6% of As and 93.0% of Fe were solubilized. The results show that pyrite bio-oxidation can promote arsenopyrite dissolution, enhance S0 bio-oxidation, and inhibit the formation of jarosites, tooeleite, and amorphous ferric arsenate...

T2.26MG-112.2 is a Ciceribacter strain that has been isolated from the deep subsurface of the Iberian Pyrite Belt. We report its draft genome consisting of a chromosome of ≈4.9 Mb and a plasmid of 357 kb. The annotation reveals 4,824 coding sequences, 48 tRNA genes, and 1 rRNA operon.

Osteosarcoma (OS) is an aggressive bone tumor with strong invasiveness, rapid metastasis, and dreadful mortality. Chemotherapy is a commonly used approach for OS treatment but is limited by the development of drug resistance and long-term adverse effects. To date, OS still lacks the curative treatment. Herein, we fabricated pyrite-based nanoparticles (FeS2 @CP NPs) as synergetic therapeutic platform by integrating photothermal therapy (PTT) and chemo-dynamic therapy (CDT) into one system. The synthetic FeS2 @CP NPs showed superior Fenton reaction catalytic activity...

Metallurgical applications of deep eutectic solvents (DESs), known as ionometallurgy, have received significant research attention in recent years. While many studies claim that DESs are generally green and enhance process efficiency, others believe that industrial applications of ionometallurgy are generally not viable. Here, we report on leaching experiments of a sulfide flotation concentrate using ethaline, a chloride-based DES, in the presence of common oxidants. Following a mineral-based approach, we compare results with those obtained from aqueous chloride solutions to assess the influence of the leaching medium...

Coal gangue (CG), an industrial solid waste with high contents of Li and Ga, has attracted the attention of researchers. However, the utilization of CG remains an economic challenge. Pre-enrichment of Li and Ga by flotation was carried out with a view to improving the comprehensive utilization of CG. Mineral composition, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and elemental composition were used to investigate the embeddedness of each mineral and the mode of elemental occurrence in the CG...

This study investigates the nitrogen removal efficacy and microbial community dynamics in seawater aquaculture effluent treatment using three different substrate combinations of microscale laboratory aerated filters (MFs) - MF1 (LECA), MF2 (LECA/Fe-C), and MF3 (LECA/Pyrite). The findings indicated that the COD removal exceeded 95% across all MFs, with higher removal efficiencies in MF2 and MF3. In terms of nitrogen removal performance, MF2 exhibited the highest average nitrogen removal of 93.17%, achieving a 12...

Designing iron-based catalysts for Fenton-like reactions with peroxymonosulfate (PMS) as oxidants have attracted growing attentions. Herein, pyrite FeS2 supported on carbon spheres (FeS2 @C) is synthesized by a facile low-temperature method. The FeS2 @C/PMS system can degrade carbamazepine (CBZ) effectively in a wide pH range. Sulfate radicals (SO4 ·- ), hydroxyl radicals (·OH), superoxide radical (O2 ·- ), and singlet oxygen (1 O2 ) are the responsible reactive oxygen species (ROSs) for CBZ degradation...

Mineral processing encounters the challenge of separating chalcopyrite and pyrite, with the conventional high alkali process characterized by issues such as large dosages of reagents, complex procedures, and environmental pollution. This study addresses this challenge by isolating and enriching Thiobacillus ferrooxidans (T·f) from acidic mine drainage, employing it as a biosurfactant. The modification mechanism of T·f was thoroughly analyzed. Fe dissolution through biological oxidation formed a passivation layer (jarosite [KFe3 (SO4 )2 (OH)6 ], elemental sulfur (S0 ), and metal sulfides (Cu/Fe-S) on the surface of minerals...

Groundwater is an essential source for drinking water production. Nitrate infiltration into groundwater due to over-fertilization can cause a potential risk for groundwater quality. Pyrite and other geogenic minerals can be oxidized and trace metals consequently released into water, e.g., nickel and uranium. To achieve a better understanding of the nitrate-induced mobilization of metals, this study investigated the release of antimony, arsenic, chromium, cobalt, molybdenum, uranium, and vanadium from three different reduced sediments after nitrate addition...

The oxidation of pyrite is the main cause of acidic mine drainage (AMD), which is a very serious environmental problem in numerous mining areas around the world. Previous studies have shown that passivation agents create a hydrophobic film on the surface of pyrite, effectively isolating oxygen and water. However, the presence of abundant sulfide minerals in tailings ponds may exacerbate AMD when exposed to solar radiation, due to the semiconductor properties of pyrite. It remains uncertain whether the current surface passivation coating can effectively prevent the oxidation of pyrite under light conditions...

Pharmaceutical residues in sediments are concerning as ubiquitous emerging contaminants. Pyrite is the most abundant sulfide minerals in the estuarine and coastal sediments, making it a major sink for pharmaceutical pollutants such as sulfamethoxazole (SMX). However, research on the adsorption and redox behaviors of SMX on the pyrite surface is limited. Here, we investigated the impact of the nonphotochemical process of pyrite on the fate of coexisting SMX. Remarkably, sulfur vacancies (SVs) on pyrite promoted the generation of nonradical species (hydrogen peroxide, H2 O2 and singlet oxygen, 1 O2 ), thereby exhibiting prominent SMX degradation performance under darkness...

Sulfur degassed at volcanic arcs calls for dissolved sulfate ions (S6+ ) released by subduction-zone fluids, oxidizing (in association with carbon) the subarc mantle, but sulfur speciation in subduction fluids at subarc depths remains unclear. We apply electrolytic fluid thermodynamics to model the dissolution behavior of pyrite in metacarbonate sediments as a function of P , T and rock redox state up to 4.3 gigapascals and 730°C. At subarc depth and the redox conditions of the fayalite-magnetite-quartz oxygen buffer, pyrite dissolution releases oxidized sulfur in fluids by disproportionation into sulfate, bisulfite, and sulfide species...

Sulfate reduction is an essential metabolism that maintains biogeochemical cycles in marine and terrestrial ecosystems. Sulfate reducers are exclusively prokaryotic, phylogenetically diverse, and may have evolved early in Earth's history. However, their origin is elusive and unequivocal fossils are lacking. Here we report a new microfossil, Qingjiangonema cambria, from ∼518-million-year-old black shales that yield the Qingjiang biota. Qingjiangonema is a long filamentous form comprising hundreds of cells filled by equimorphic and equidimensional pyrite microcrystals with a light sulfur isotope composition...

Natural pyrite (NP) is an alternative catalyst for wastewater purification via advanced oxidation processes (AOPs). However, the activation performance and mechanism of periodate (PI) by NP have not yet been revealed. Herein, this work examines the activation performance of NP towards PI and its application in the degradation of antibiotic wastewater. Interestingly, 95.69% of chlortetracycline (CTC) was degraded by NP within 20 min via PI activation. Besides, NP shows effective degradation of various pollutants such as rhodamine B (65...

Laccase immobilized and cross-linked on Fe3 S4 /earthworm-like mesoporous SiO2 (Fe3 S4 /EW-mSiO2 ) was used to degrade methoxychlor (MXC) in aqueous environments. The effects of various parameters on the degradation of MXC were determined using free and immobilized laccase. Immobilization improved the thermal stability and reuse of laccase significantly. Under the conditions of pH 4.5, temperature 40 °C, and reaction time 8 h, the degradation rate of MXC by immobilized laccase reached a maximum value of 40...