Soils around coal mining are important reservoir of hazardous elements (HEs), nanominerals, and ultrafine compounds. This research reports and discusses the soil concentrations of HEs (As, Cd, Cr, ...Cu, Ni, Pb, and Zn) in coal residues of abandoned mines.
To assess differences regarding environmental impact and risk assessment between coal abandoned mines from the Santa Catarina state, eighteen coal cleaning rejects with different mineralogical and chemical composition, from eight abandoned mines were collected.
Nanominerals and ultra-fine minerals from mining-contaminated areas were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscope (HR-TEM), providing new information on the mineralogy and nano-mineralogy of these coal residues. The total contents of 57 elements (HEs, alkali metals, and rare earth elements) were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The calculation of NWACs (Normalized Average Weighted Concentration), together with the chemometric analysis by Principal component analysis (PCA) confirmed the variability of the samples regarding their city and their mine of origin. Moreover, the results confirmed the existence of hotspots in mines near urban areas.
•Assessment of the human health and environmental implications of abandoned Brazilian coal area was performed.•Grave effort should be made to set clear restrictions of generated soil utilization in agricultural activities.•The analytical procedure has been applied to investigate elements occurrence in ultra-fine and nano-particles.
•Four anthracites and one anthracite-rank carbonaceous shale were analyzed.•Three of the coals showed an enrichment in the middle to heavy rare earths.•The Virginia anthracite showed substitution of ...As, Hg, and Se in pyrite.•Carbon nanotubes were observed in the three highest-rank coals.
Petrographic, geochemical, and electron microbeam investigations of selected anthracites and anthracite-rank coaly shales were conducted. The Pennsylvania, Rhode Island, and KwaZu-Natal anthracites show an enrichment in the middle to heavy rare earths (REE) while the Virginia semi-anthracite exhibited a decreasing trend through the light REE, a peak in Gd, and a depletion in the heavy REE. Substitution of As, Hg, and Se in pyrite was most apparent in the Virginia coal. The Pennsylvania, Rhode Island, and KwaZu-Natal anthracites contained spherical carbon nanotube (CNT) structures. The CNTs contained several elements, including Hg, Cd, F, Cl, and Br. While CNTs are known to be produced from coals of varying ranks, this seems to be the first report of naturally occurring CNTs.
The coal (anthracite A) in Douro Coalfield (NW of Portugal) has been exploited for many years and has been mainly used as fuel supply by a thermal power plant. The mining activities inevitably ...impacted the environment, which includes a large number of coal waste piles emplaced over the old mine sites and adjacent areas of the Douro Coalfield. The disposal of coal mining residues represents significant environmental concerns due to their potential influence on soils and sediments, as well as on the surface and groundwater of the surrounding areas. In the present study, the development of sequential extraction combined with various advanced analytical techniques was performed to provide an improved understanding of the complex processes related with sulfide-rich coal waste oxidation, sequences of mineral formation, and the transport mechanisms of hazardous elements by specific neoformed soluble minerals. The results showed the presence of amorphous iron (oxy-) hydroxides and goethite with various degrees of crystallinity, containing hazardous elements, such as As, Cr, Hg, Mo, Se, Pb, U, and others. Some of the neoformed minerals found in the coal waste material are the same as those commonly associated with coal acid drainage, in which oxidation of sulfides plays an important role. The precipitated neoformed minerals include pickeringite, blödite, and a mixture of epsomite, pickeringite, and hexahydrite. As these sulfates may dissolve after the first rain, they may release above-mentioned elements into surrounding water bodies.
► Oxidation is the major process for mineral transformation in coal waste. ► The electron bean methodology has been applied to investigate neoformed minerals. ► Coal waste geochemisty can provide increase information in coal-ming areas.
In this study, avocado seed was successfully used as raw material for producing activated carbons by conventional pyrolysis. In order to determine the best condition to produce the activated carbons, ...a 2
2
full-factorial design of experiment (DOE) with three central points was employed by varying the temperature and time of pyrolysis. The two evaluated factors (temperature and time of pyrolysis) strongly influenced the
S
BET
, pore volumes, hydrophobicity–hydrophilicity ratio (HI) and functional groups values; both factors had a negative effect over
S
BET
, pore volumes and functional groups which means that increasing the values of factors leads to decrease of these responses; on the other hand, with regards to HI, both factors caused a positive effect which means that increasing their values, the HI has an enhancement over its values. The produced activated carbon exhibited high specific surface areas in the range of 1122–1584 m
2
g
−1
. Surface characterisation revealed that avocado seed activated carbons (ASACs) have hydrophilic surfaces and have predominantly acidic groups on their surfaces. The prepared ASACs were employed in the adsorption of 25 emerging organic compounds such as 10 pharmaceuticals and 15 phenolic compounds which presented high uptake values for all emerging pollutants. It was observed that the activated carbon prepared at higher temperature of pyrolysis (700 °C), which generated less total functional groups and presented higher HI, was the activated carbon with higher sorption capacity for uptaking emerging organic contaminants. Based on results of this work, it is possible to conclude that avocado seed can be employed as a raw material to produce high surface area and very efficient activated carbons in relation to treatment of polluted waters with emerging organic pollutants.
Atmosphere contamination management is one of the most important features in pollution risk management. The worldwide rise in tourism increases apprehension about its probable destructive ...conservation influence on various aspects of global conservation. One of the principal dangers increased by tourism-based modes of travel are nanoparticles (NPs) containing potentially hazardous elements (PHEs) contamination. One example of this is island destination of Lanzarote, in Spain’s Canary Islands in which we examined contamination of the local atmosphere, water and soil. Important NPs containing PHEs, (e.g. arsenic, chromium, lead, and mercury), were found in this locale. It is reasonable to assume that this pollution poses an increased environmental danger to the local biome(s). Modes of transport (i.e. by car, airplane, bus) were shown to be an important contributor to this localized contamination as demonstrated by particulate matter (PM) readings collected near the island’s airport. If no measures are taken to reduce vehicle and aircraft traffic, the tendency is to increase environmental degradation will continue unabated. As this particular area of Lanzarote is also one of wine production, increased pollution has the potential for negative impacts on the region’s economy.
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•The volcanic and human impacts by nanoparticles has been found out on Canary Island.•A work of nanoparticles and hazardous elements association were executed.•The pollution may characterize a reasonable environmental danger to native systems.•Continuous traffic is an important cause of topsoil contamination on the Lanzarote.
Detailed geochemistry similarities between the burning coal cleaning rejects (BCCRs) and non-anthropogenic geological environments are outlined here. While no visible flames were detected, this ...research revealed that auto-combustion existed in the studied area for many years. The occurrence of several amorphous phases, mullite, hematite and many other Al/Fe-minerals formed by high temperature was found. Bad disposal of coal-dump wastes represents significant environmental concerns due to their potential influence on atmosphere, river sediments, soils and as well as on the surface and groundwater in the surroundings of these areas. The present work using multi-analytical techniques were performed to provide an improved understanding of the complex processes related with sulphide-rich coal waste oxidation, spontaneous combustion and newmineral creation. It recording huge numbers of rare minerals with alunite, montmorillonite, szmolnockite, halotrichite, coquimbite and copiapite at the BCCRs. The information presented the presence of abundant amorphous Si–Al–Fe–Ti as (oxy-)hydroxides and Fe-hydro/oxides with goethite and hematite with various degrees of crystallinity, containing potential hazardous elements (PHEs), such as Cu, Cr, Hf, Hg, Mo, Ni, Se, Pb, Th, U, Zr, and others. Most of the nano-particles and ultra-fine particles found in the burned coal-dump wastes are the same as those commonly associated with coal cleaning rejects, in which oxidation of sulphides plays an important impact to environment and subsequently animal and human health.
•Evaluation of the environmental impact of abandoned Brazilian coal fires area was performed.•Grave effort should be made to set clear restrictions of gendered soil utilization in cement industry.•The multi-analytical methodology has been applied to investigate elements occurrence in ultra-fine and nano-particles.
A rise in temperature triggers a structural change in the human Type I 40 kDa heat shock protein (Hsp40/DnaJ), known as DNAJA1. This change leads to a less compact structure, characterized by an ...increased presence of solvent‐exposed hydrophobic patches and β‐sheet‐rich regions. This transformation is validated by circular dichroism, thioflavin T binding, and Bis‐ANS assays. The formation of this β‐sheet‐rich conformation, which is amplified in the absence of zinc, leads to protein aggregation. This aggregation is induced not only by high temperatures but also by low ionic strength and high protein concentration. The aggregated conformation exhibits characteristics of an amyloidogenic structure, including a distinctive X‐ray diffraction pattern, seeding competence (which stimulates the formation of amyloid‐like aggregates), cytotoxicity, resistance to SDS, and fibril formation. Interestingly, the yeast Type I Ydj1 also tends to adopt a similar β‐sheet‐rich structure under comparable conditions, whereas Type II Hsp40s, whether human or from yeast, do not. Moreover, Ydj1 aggregates were found to be cytotoxic. Studies using DNAJA1‐ and Ydj1‐deleted mutants suggest that the zinc‐finger region plays a crucial role in amyloid formation. Our discovery of amyloid aggregation in a C‐terminal deletion mutant of DNAJA1, which resembles a spliced homolog expressed in the testis, implies that Type I Hsp40 co‐chaperones may generate amyloidogenic species in vivo .
Sediments from coal mine drainages (CMDs) contain large quantities of suspended pollutants (possibly numerous chemical substances) along with sulfates and hazardous elements (e.g., chromium, zinc, ...copper, lead) that irreversibly accumulate in the water. As this accumulation can continue for decades after discontinuation of coal extraction, it is necessary to employ multidisciplinary approaches to control the threat in such zones. The quantity of amorphous material in some CMDs was evaluated by X-ray powder diffraction (XRD) using the Rietveld-based SIROQUANT software package. Modern Dual Beam Focused Ion Beam (FIB), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscope (H-TEM), and energy-dispersive X-ray spectrometer (EDS) were used to evaluate the occurrence and transformation of nanophases (NPs). FIB is used to determine the 3D distribution of different species (internal structure) within individual NPs, whereas EDS is used to observe NP features (e.g., shape, constituent, range, assembly, and form of polymerization). The mineralogy of the sediment from the Brazilian CMDs, including the proportions of quartz, clays, Al–Fe-oxides, and amorphous NPs, appears to be related to the nature of the mineral matter in the relevant coal cleaning rejects (CCRs). The sediments of CMDs from the Brazilian coal area derived at a lower-pH range have different amorphous compositions as compared to those derived at a higher pH range. These special amorphous compositions are shown to be related to several other sediment properties such as particle surface area. The information gleaned in this study will be useful for further geochemical evaluation of CMDs in other parts of the world.
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•Coal rejects, an acidic mine waste, is mixed with clay, a basic waste.•The effects of nanominerals and saturated sand barrier are studied.•Iron sulphides and extractable heavy metals increased in excess of critical limits.•This work is complemented with field measurements and chemical modeling.
•Medicinal plants have antimicrobial activity on oral microorganism’s producers of volatile sulphur compounds.•They have the potential to reduce halitosis of oral origin.•The Pomegranate extract was ...the only extract that inhibited all the evaluated microorganisms.
This study aimed to evaluate the in vitro activity of the crude extracts obtained from Caesalpinia ferrea Mart. (Jucá), Cinnamomum cassia B. (Cinnamon), Mallow sylvestris L. (Mallow), Punica granatum L. (Pomegranate), Rosmarinus officinalis L. (Rosemary), Aeolanthus suaveolens (Als.) Spreng. (Macassá), Sysygium aromaticum L. (Clove), and Tamarindus indica L. (Tamarind) against oral microorganisms (e.g., Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, and Parvimonas micra) that produce volatile sulfur compounds (VSC). The pure extracts were placed in culture medium for the diffusion test in agar. The Minimum Inhibitory Concentration (MIC) was determined by the microdilution method, and microbial growth was assayed with resazurin. Total polyphenols in the extracts were measured by using the Prussian Blue Method. For the salivary sediment test, the sediments were exposed to the Jucá and Pomegranate extracts, which was followed by incubation and organoleptic measurements with a monitor (Halimeter®) at 1-, 2-, 4-, and 24 -h intervals. The diffusion test revealed mixed results for the extracts. When the zone of inhibition was present, it ranged from 1.6–10.3 mm. The Pomegranate extract was the only extract that inhibited all the evaluated microorganisms; the MIC values ranged from 50 to 400 μg/mL. The Pomegranate and Jucá extracts presented higher levels of polyphenols, 7.3 % and 3.9 %, respectively, and less VSC formation as compared to the negative control. In conclusion, the extracts display antimicrobial activity against the tested microorganisms. The investigated plants have the potential to reduce the main substances related to halitosis of oral origin.
Sludge-derived activated carbons (ACs) were prepared by conventional heating and microwave pyrolysis. The ACs were characterized using several analytical and functional techniques and used for ...removal of six phenolic compounds from aqueous solutions. The adsorbents exhibited similar features and possessed hydrophobic surfaces. The ACs were assigned mesoporous materials, with specific surface areas of up to 641 and 540 m
2
g
−1
for CAC-500 and MAC-980, respectively. The preliminary results indicated that phenol removal onto the ACs increased in the order: m-cresol < phenol < o-cresol < 2-chrorophenol < 2-nitrophenol < hydroquinone. Hydroquinone exhibited the highest adsorption capacity and was chosen to continue the remaining part of the experimental work—kinetic and isothermal studies. The adsorption kinetic and isotherm data were well described by the Avrami fractionary order and Redlich–Peterson models, respectively. The maximum amounts (
Q
max
) of hydroquinone adsorbed at 25 °C were too high, reaching 1218.3 and 1202.1 mg g
−1
for CAC-500 and MAC-980, respectively. The mechanism of adsorption was proposed in this work, and it was suggested that donor–acceptor complex and
π
–
π
interactions play major roles in the adsorption process. The adsorbents were also tested on simulated effluents. The two ACs displayed good efficiency for the treatment of industrial simulated effluents.
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