Mercury biomagnification in the food chain of a piscivorous turtle species (Testudines: Chelidae: Chelus fimbriata) in the Central Amazon, Brazil.

Due to their natural history and ecological attributes, turtles are excellent organisms for studies of heavy metal contamination. Turtles have a large geographical distribution, occupy different aquatic habitats, and occupy various trophic levels. The present study investigated mercury bioaccumulation in the carnivorous chelonian Chelus fimbriata (Matamata turtle) and Hg biomagnification in relation to its aquatic food chain in the middle Rio Negro, AM-Brazil.

A techno-economic analysis of diesel exhaust injection into mine tailings for carbon sequestration.

The environmental impact of off-grid mines in remote, cold climates is significantly intensified by their dependence on fossil fuels for power and heating. A promising solution lies in the potential to capture and permanently store carbon within mine tailings, thus allowing the mining industry to take a leading role in carbon removal initiatives and provide sustainable solutions. This study explores energy-optimal design scenarios for flue gas injection into mine waste to capture carbon.

Parameters and surrounding rock control of gob-side driving under double key stratum after roof cutting.

Taking the return-airway 4204 with roof cutting in Longquan Coal Mine as the engineering background, roof structure, key parameters, and deviatoric stress evolution were studied. Conclusion: The Key Stratum within a 4-8 times mining height is considered as Near Key Stratum. Cutting the roof makes it possible to form a cantilever structure of the Key Stratum on the solid coal side, which is more conducive to the stability of gob-side roadway.

Synthetic biology tools for environmental protection.

Synthetic biology transforms the way we perceive biological systems. Emerging technologies in this field affect many disciplines of science and engineering. Traditionally, synthetic biology approaches were commonly aimed at developing cost-effective microbial cell factories to produce chemicals from renewable sources.

Acute ecotoxicological effects of Hg(CN) in Danio rerio (zebrafish).

Artisanal and small-scale gold mining (ASGM) is the largest source of anthropogenic Hg emissions on the planet. In addition, Hg-contaminated tailings are often reprocessed with sodium cyanide (NaCN) to extract the residual gold remaining in the material. This leads to the formation of mercury cyanide (Hg(CN)) complexes, which are often discharged in untreated form into local drainages, leading to large amounts of free cyanide being released.

GIPPE-RPT: Geant4 interface for particle physics experiments applied to Radioactive Particle Tracking.

Radioactive Particle Tracking (RPT) is a non-invasive experimental technique that tracks the motion of a gamma-emitting radionuclide. Despite the RPT's high versatility, the lack of dedicated software represents a significant barrier to its wider adoption. This article introduces a new software, GIPPE-RPT, designed to bring the technique closer to a wider group of users.

Cyanide Contamination of the Puyango-Tumbes River Caused by Artisanal Gold Mining in Portovelo-Zaruma, Ecuador.

Purpose Of Review: To examine cyanide (CN-) contamination of a large river in southeastern Ecuador that has been severely impacted by the indiscriminate discharge of untreated gold processing effluents.

Recent Findings: Poor environmental stewardship of cyanide (CN-) use by 87 gold processing centers in Portovelo-Zaruma in southern Ecuador to leach residual gold from Hg-contaminated tailings has resulted in high CN- contamination of the Puyango-Tumbes River downstream from the centers. Free CN- concentrations were high in river surface waters for 50 km below the processing plants, with the highest concentration 9088 times above the CCME standard of 5 μg/L and 1136 times above the 24-h LC concentration of 40 μg/L free CN- for some fish species.

Preparation of a Composite Calcium Silicate Board with Carbide Slag and Coal-Based Solid Waste Activated by Different Alkali Activators.

Overall performance of composite calcium silicate boards (CCSBs) was investigated to further promote their application. The alkali activators were used to fully hydrate the calcium and silicon raw materials, which further improved the comprehensive performance of the CCSBs made of four pure industrial solid wastes. Within the range of dosage in this study, single doping of different proportions of the alkali activator improved the flexural strength of the CCSB.

Distinguishing reclamation, revegetation and phytoremediation, and the importance of geochemical processes in the reclamation of sulfidic mine tailings: A review.

The reclamation of tailings, especially acid-generating tailings resulting from the oxidation of sulfide minerals, has been an urgent but difficult task for a long period. Phytoremediation has been received great concerns in the area of metal (loid)s removal in recent two decades. However, in the reclamation of tailings, the term "revegetation" has been mentioned frequently.

Mobilization of Metal(oid) Oxyanions through Circumneutral Mine Waste-Rock Drainage.

Most studies on the weathering of mine waste rock focus on the generation of acidic drainage with high metal concentrations, whereas metal(loid) release under neutral-rock drainage (NRD) conditions has received limited attention. Here, we present geochemical and mineralogical data from a long-term (>10 years) kinetic testing program with 50 waste-rock field barrels at the polymetallic Antamina mine in Peru. The weathering of most rock lithologies in the field experiments generated circumneutral to alkaline drainage (6 < pH < 9) but with concentrations of the oxyanion-forming metal(loid)s As, Mo, Se, and Sb in the mg/L range.

Response to Critique of "The Insignificance of Thresholds in Environmental Impact Assessment: An Illustrative Case Study in Canada".

Our paper, "The Insignificance of Thresholds in Environmental Impact Assessment: An Illustrative Case Study in Canada" received a critique that challenged us on a number of grounds. Namely, that we defame EIA practitioners, that we advocate EIAs to become a scientific enterprise, that we do not recognize the complexity inherent in EIA, and that EIA undergo an independent assessment by regulators. We respond to all of these points, and argue that conflict of interest is an institutional issue (not one of corrupt practitioners), and that we critique the science that forms the basis of evidence in EIA.

Mercury isotopic signatures of tailings from artisanal and small-scale gold mining (ASGM) in southwestern Ecuador.

Artisanal and small-scale gold mining (ASGM) is currently one of the largest anthropogenic sources of mercury (Hg) to the atmosphere and a significant source to downstream terrestrial aquatic systems. Given the potential toxicity of Hg when it is released to aquatic ecosystems, both scientific and regulatory communities have interest in the development of tools and methods for understanding the fate and transport of Hg in the environment. Although Hg isotopes are applied extensively to trace other anthropogenic point sources of Hg in aquatic ecosystems, few studies have used isotopic analyses to investigate the downstream impacts of ASGM.

Training artisanal miners: A proposed framework with performance evaluation indicators.

Worldwide, approximately 30 million people depend directly on artisanal mining of many different minerals to provide for themselves and their families. However, poverty and a lack of education and training keep artisanal miners trapped in a cycle of rudimentary practices, which generate both environmental and health impacts. As the needs and motivations of artisanal miners are often ignored, previous attempts to deliver training projects have resulted in little sustained success.

An investigation of mercury sources in the Puyango-Tumbes River: Using stable Hg isotopes to characterize transboundary Hg pollution.

Mercury (Hg) concentrations and stable isotopes along with other trace metals were examined in environmental samples from Ecuador and Peru's shared Puyango-Tumbes River in order to determine the extent to which artisanal- and small-scale gold mining (ASGM) in Portovelo-Zaruma, Ecuador contributes to Hg pollution in the downstream aquatic ecosystem. Prior studies investigated the relationship between ASGM activities and downstream Hg pollution relying primarily on Hg concentration data. In this study, Hg isotopes revealed an isotopically heavy Hg signature with negligible mass independent fractionation (MIF) in downstream sediments, which was consistent with the signature observed in the ASGM source endmember.

Identification of lanthanum-specific peptides for future recycling of rare earth elements from compact fluorescent lamps.

As components of electronic scrap, rare earth minerals are an interesting but little used source of raw materials that are highly important for the recycling industry. Currently, there exists no cost-efficient technology to separate rare earth minerals from an electronic scrap mixture. In this study, phage surface display has been used as a key method to develop peptides with high specificity for particular inorganic targets in electronic scrap.

Identification of mineral-binding peptides that discriminate between chalcopyrite and enargite.

Innovative approaches to the separation of minerals and subsequent extraction of metals are imperative owing to the increasing mineralogical complexity of ore deposits that are difficult or even impossible to separate into slurries or solutions containing only the minerals or metals of interest. Low recovery of metal is typical for these complex deposits leading to significant losses to tailings. In addition, the minerals often contain impurities, some toxic, which are difficult and costly to control or manage during the processing of a concentrate or other mineral product.

Cyanidation of Mercury-Contaminated Tailings: Potential Health Effects and Environmental Justice.

There is a variety of health and environmental issues associated with artisanal and small-scale gold mining (ASGM), which includes concerns regarding mercury pollution. In many countries, intervention programs and policies emphasized the importance of reducing mercury use by focusing on viable alternative methods to amalgamation that may include a transition to cyanidation. ASGM communities that now employ a combination of both methods may be increasing health and environmental risks by using mercury-contaminated tailings in the cyanidation process.

Biotechnology and the Mine of Tomorrow.

Biotechnology could provide many innovative alternatives for changing the way metals are obtained. Microbes have been used to dissolve metallic minerals and release metal ions into solution, from which pure metal can be obtained by electrolysis. Plants that accumulate metals in their roots and leaves have been used to concentrate metals, and mineral-binding peptides might be used to separate minerals.

The effect of acidic pH and presence of metals as parameters in establishing a sulfidogenic process in anaerobic reactor.

The successful use of anaerobic reactors for bioremediation of acid mine drainage has been shown in systems with neutral pH. However, the choice of an efficient and suitable process for such wastewater must consider the capability of operating at acidic pH and in the presence of metals. This work studies the performance of an anaerobic batch reactor, under conditions of varying initial pH for its efficiencies in sulfate removal and metal precipitation from synthetic acid mine drainage.

Dilute solution properties of carboxymethyl celluloses of various molecular weights and degrees of substitution.

The intrinsic viscosities of six carboxymethyl celluloses (CMC) of different degrees of substitution, molecular weights, and molecular weight distributions (MWDs) were measured as a function of pH, ionic strength, and temperature. The molecular weights and MWDs were determined by analytical ultracentrifugation. It was demonstrated that the raw viscosity data could be represented by the Fedors equation allowing for accurate determination of the intrinsic viscosity.

Bacteriophage-induced aggregation of oil sands tailings.

Very large quantities of tailings are produced as a result of processing oil sands. After the sand particles settle out, a dense stable mixture of clay, silt, water with residual bitumen, salts, and organics called mature fine tailings (MFT) can remain in suspension for decades. Research into developing methods that would allow consolidation and sedimentation of the suspended particles is ongoing.

Effects of bacteriophage on the surface properties of chalcopyrite (CuFeS₂), and phage-induced flocculation of chalcopyrite, glacial till, and oil sands tailings.

The binding of mineral-specific phage to the surface of chalcopyrite (CuFeS(2)) was investigated by using X-ray photoelectron spectroscopy and scanning Auger microscopy. These studies confirmed the elemental composition of the minerals and confirmed that bacteriophage were bound to the mineral surface. These techniques also revealed that the phage were not forming a continuous film over the entire surface of the CuFeS(2) particles, but selectively bound to the slimes coating the particles.