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1.
J Hazard Mater ; 470: 134200, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38593661

RESUMO

Non-ferrous metal smelting emits large amounts of organic compounds into the atmosphere. Herein, 20 parent polycyclic aromatic hydrocarbons (PPAHs), 9 nitrated PAHs (NPAHs), 14 chlorinated PAHs (ClPAHs), and 6 alkylated PAHs (APAHs) in atmospheric samples from a typical non-ferrous metal smelting plant (NMSP) and residential areas were detected. In NMSP, benzo[a]pyrene, dibenz[a,h]anthracene, 6-nitrochrysene, 9-chlorofluorene, and 1-methylfluorene were the predominant compounds in the particulate phase, while phenanthrene constituted 57.3% in the gaseous phase. The concentration of PAHs in residential areas around NMSP was 1.8 times higher than that in the control area. Additionally, there was a significant negative correlation between the concentration and the distance from the NMSP. In terms of health risks, although the skin penetration coefficient of PM2.5 is smaller than that of the gaseous phase, dermal absorption of PM2.5 posed a greater threat to the population, the incremental lifetime cancer risk (ILCR) of NMSP was 1.8 × 10-4. After considering bioavailability, BILCR decreased by 1-2 orders of magnitude in different regions, and dermal absorption decreased more than inhalation intake. Nevertheless, the dermal absorption of PM2.5 in NMSP still presents a probable carcinogenic risk. This study provides a necessary reference for the subsequent control of NMSP contamination.


Assuntos
Poluentes Atmosféricos , Disponibilidade Biológica , Metalurgia , Hidrocarbonetos Policíclicos Aromáticos , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Atmosféricos/análise , Humanos , Medição de Risco , Material Particulado/análise , Monitoramento Ambiental
2.
J Environ Sci (China) ; 143: 60-70, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38644024

RESUMO

Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological environment. Soil samples were collected from different depths (0 to 13 m) and analyzed for metal(loid)s content and fractionation, as well as microbial activities. The potential ecological risk indices for the different soil depths (ordered from high to low) were: 1 m (D-1) > surface (S-0) > 5 m (D-5) > 13 m (D-13) > 9 m (D-9), ranging between 1840.65-13,089.62, and representing extremely high environmental risks, of which Cd (and probably not arsenic) contributed to the highest environmental risk. A modified combined pollution risk index (MCR) combining total content and mobile proportion of metal(loid)s, and relative toxicities, was used to evaluate the degree of contamination and potential environmental risks. For the near-surface samples (S-0 and D-1 layers), the MCR considered that As, Cd, Pb, Sb, and Zn achieved high and alarming degrees of contamination, whereas Fe, Mn, and Ti were negligible or low to moderate pollution degrees. Combined microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity characteristics. Correlation analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics (p < 0.05). The microbial metabolic activity in the D-1 layer was low presumably due to heavy metal stress. Enzyme activity indicators and microcalorimetric growth rate (k) measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites.


Assuntos
Monitoramento Ambiental , Microbiologia do Solo , Poluentes do Solo , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Solo/química , Medição de Risco , Metais Pesados/análise , Metais Pesados/toxicidade , Metalurgia , Metais/toxicidade , Metais/análise
3.
Sci Total Environ ; 927: 171892, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38531450

RESUMO

The majority of the studies on nanoscale zero-valent iron (nZVI) are conducted at a laboratory-scale, while field-scale evidence is scarce. The objective of this study was to compare the metal(loid) immobilization efficiency of selected Fe-based materials under field conditions for a period of one year. Two contrasting metal(loid) (As, Cd, Pb, Zn) enriched soils from a smelter-contaminated area were amended with sulfidized nZVI (S-nZVI) solely or combined with thermally stabilized sewage sludge and compared to amendment with microscale iron grit. In the soil with higher pH (7.5) and organic matter content (TOC = 12.7 %), the application of amendments resulted in a moderate increase in pH and reduced As, Cd, Pb, and Zn leaching after 1-year, with S-nZVI and sludge combined being the most efficient, followed by iron grit and S-nZVI alone. However, the amendments had adverse impacts on microbial biomass quantity, S-nZVI being the least damaging. In the soil with a lower pH (6.0) and organic matter content (TOC = 2.3 %), the results were mixed; 0.01 M CaCl2 extraction data showed only S-nZVI with sludge as remaining effective in reducing extractable concentrations of metals; on the other hand, Cd and Zn concentrations were increased in the extracted soil pore water solutions, in contrast to the two conventional amendments. Despite that, S-nZVI with sludge enhanced the quantity of microbial biomass in this soil. Additional earthworm avoidance data indicated that they generally avoided soil treated with all Fe-based materials, but the presence of sludge impacted their preferences somewhat. In summary, no significant differences between S-nZVI and iron grit were observed for metal(loid) immobilization, though sludge significantly improved the performance of S-nZVI in terms of soil health indicators. Therefore, this study indicates that S-nZVI amendment of soils alone should be avoided, though further field evidence from a broader range of soils is now required.


Assuntos
Ferro , Poluentes do Solo , Solo , Poluentes do Solo/análise , Ferro/química , Solo/química , Metais Pesados/análise , Nanopartículas Metálicas/química , Metalurgia , Recuperação e Remediação Ambiental/métodos
4.
Int Endod J ; 57(5): 601-616, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38376108

RESUMO

AIM: To compare eight large- and low-tapered heat-treated reciprocating instruments regarding their design, metallurgy, mechanical properties, and irrigation flow through an in silico model. METHODOLOGY: A total of 472 new 25-mm E-Flex Rex (25/.04 and 25/.06), Excalibur (25/.05), Procodile (25/.06), Reciproc Blue R25 (25/.08v), WaveOne Gold Primary (25/.07v), and Univy Sense (25/.04 and 25/.06) instruments were evaluated regarding their design (stereomicroscopy, scanning electron microscopy, and 3D surface scanning), metallurgy (energy-dispersive X-ray spectroscopy and differential scanning calorimetry), and mechanical performance (cyclic fatigue, torsional resistance, cutting ability, bending and buckling resistance). Computational fluid dynamics assessment was also conducted to determine the irrigation flow pattern, apical pressure, and wall shear stress in simulated canal preparations. Kruskal-Wallis and one-way anova post hoc Tukey tests were used for statistical comparisons (α = 5%). RESULTS: Instruments presented variations in blade numbers, helical angles, and tip designs, with all featuring non-active tips, symmetrical blades, and equiatomic nickel-titanium ratios. Cross-sectional designs exhibited an S-shaped geometry, except for WaveOne Gold. Univy 25/.04 and Reciproc Blue displayed the smallest and largest core diameters at D3. Univy 25/.04 and E-Flex Rec 25/.04 demonstrated the longest time to fracture (p < .05). Reciproc Blue and Univy 25/.04 exhibited the highest and lowest torque to fracture, respectively (p < .05). Univy 25/.04 and Reciproc Blue had the highest rotation angles, whilst E-Flex Rec 25/.06 showed the lowest angle (p < .05). The better cutting ability was observed with E-Flex Rec 25/.06, Procodile, Excalibur, and Reciproc Blue (p > .05). Reciproc R25 and E-Flex Rec showed the highest buckling resistance values (p < .05), with WaveOne Gold being the least flexible instrument. The impact of instruments' size and taper on wall shear stress and apical pressure did not follow a distinct pattern, although Univy 25/.04 and E-Flex Rec 25/.06 yielded the highest and lowest values for both parameters, respectively. CONCLUSIONS: Low-tapered reciprocating instruments exhibit increased flexibility, higher time to fracture, and greater angles of rotation, coupled with reduced maximum bending loads and buckling strength compared to large-tapered instruments. Nevertheless, low-tapered systems also exhibit lower maximum torque to fracture and inferior cutting ability, contributing to a narrower apical canal enlargement that may compromise the penetration of irrigants in that region.


Assuntos
Instrumentos Odontológicos , Titânio , Estudos Transversais , Desenho de Equipamento , Teste de Materiais , Estresse Mecânico , Titânio/química , Preparo de Canal Radicular , Metalurgia
5.
J Environ Sci (China) ; 140: 46-58, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38331514

RESUMO

Reducing CO2 emissions of the iron and steel industry, a typical heavy CO2-emitting sector, is the only way that must be passed to achieve the 'dual-carbon' goal, especially in China. In previous studies, however, it is still unknown what is the difference between blast furnace-basic oxygen furnace (BF-BOF), scrap-electric furnace (scrap-EF) and hydrogen metallurgy process. The quantitative research on the key factors affecting CO2 emissions is insufficient. There is also a lack of research on the prediction of CO2 emissions by adjusting industrial structure. Based on material flow analysis, this study establishes carbon flow diagrams of three processes, and then analyze the key factors affecting CO2 emissions. CO2 emissions of the iron and steel industry in the future is predicted by adjusting industrial structure. The results show that: (1) The CO2 emissions of BF-BOF, scrap-EF and hydrogen metallurgy process in a site are 1417.26, 542.93 and 1166.52 kg, respectively. (2) By increasing pellet ratio in blast furnace, scrap ratio in electric furnace, etc., can effectively reduce CO2 emissions. (3) Reducing the crude steel output is the most effective CO2 reduction measure. There is still 5.15 × 108-6.17 × 108 tons of CO2 that needs to be reduced by additional measures.


Assuntos
Poluentes Atmosféricos , Ferro , Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Aço , Carbono , Metalurgia , Hidrogênio
6.
J Mech Behav Biomed Mater ; 152: 106466, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38387120

RESUMO

Ti-15Mo/HA composite was prepared by powder metallurgy, and the influence of Hydroxyapatite (HA) on the microstructure, tribological behavior and in vitro biocompatibility was studied by comparison with TC4. The results show that the Ti-15Mo/HA composite consists of increased α-Ti, decreased ß-Ti and a variety of ceramic phases (CaTiO3, Ca3(PO4)2, CaO, etc.) with the increase of HA content. The friction coefficient and wear rate of Ti-15Mo/HA composite is apparently lower than those of TC4 due to solid solution strengthening of Mo in Ti and dispersion strengthening of ceramic phases. Ti-15Mo/5HA displays more excellent wear resistance than the other composite. TC4 alloy is dominated by adhesive wear, however, Ti-15Mo alloy is a combination of adhesive wear and abrasive wear. Ti-15Mo/HA composite is mainly subjected to abrasive wear, together with adhesive wear. The viability and the number of mouse osteoblasts in Ti-15Mo/5HA extract are higher than that of Ti-15Mo. The morphology of the osteoblasts is clear and full, and the growth and proliferation are satisfactory with the increased cell pseudopodia with the culture time. The Ti-15Mo/HA composite displays good wear resistance and biocompatibility, and accordingly has a potential application in bone repair materials.


Assuntos
Cerâmica , Titânio , Animais , Camundongos , Pós , Titânio/farmacologia , Durapatita , Metalurgia
8.
Waste Manag ; 175: 121-132, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38194797

RESUMO

Kish graphite is a typical byproduct of steel production, and its enrichment and purification are essential prerequisites for its high value and comprehensive utilization. To solve the problem of recovery and application of difficult-to-treat kish graphite with a small particle size obtained from metallurgical dust, kish graphite in blast furnace tapping yard dust was effectively enriched and purified by a comprehensive flotation-acid leaching treatment process in this study. The influence of the flotation agents on the flotation process was explored. The results showed that the optimized flotation agent dosage was 500.0 g·t-1 (collector) and 120.0 g·t-1 (frother), respectively. Based on the optimized flotation scheme, a graphite concentrate (FG) with 79.12 % carbon content and 93.5 % carbon recovery was obtained. After the leaching treatment with a HCl-HF mixed acid solution, the carbon content of the graphite concentrate increased to 95.55 %. The ID/IG value of the graphite concentrate was 0.145, and the average lattice spacing was approximately 0.3354 nm. The SEM results showed that the leaching-treated graphite concentrate (AFG) had a loose, fragment-like structure. When used as an anode material for lithium-ion batteries, The AFG still provided a high reversible capacity of âˆ¼370 mAh·g-1 and excellent coulombic efficiency of 99.6 % after 350 cycles. In addition, an industrial-grade recycling and utilization path for kish graphite based on a circular supply chain strategy was proposed. The results of this study may serve as a conceptual basis for the recovery and application of kish graphite from metallurgical dust.


Assuntos
Grafite , Carbono , Poeira , Fontes de Energia Elétrica , Metalurgia
9.
J Environ Manage ; 352: 120051, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38262282

RESUMO

With the rapid growth of the metallurgical industry, there is a significant increase in the production of metallurgical slags. The waste slags pose significant challenges for their disposal because of complex compositions, low utilization rates, and environmental toxicity. One promising approach is to utilize metallurgical slags as catalysts for treatment of refractory organic pollutants in wastewater through advanced oxidation processes (AOPs), achieving the objective of "treating waste with waste". This work provides a literature review of the source, production, and chemical composition of metallurgical slags, including steel slag, copper slag, electrolytic manganese residue, and red mud. It emphasizes the modification methods of metallurgical slags as catalysts and the application in AOPs for degradation of refractory organic pollutants. The reaction conditions, catalytic performance, and degradation mechanisms of organic pollutants using metallurgical slags are summarized. Studies have proved the feasibility of using metallurgical slags as catalysts for removing various pollutants by AOPs. The catalytic performance was significantly influenced by slags-derived catalysts, catalyst modification, and process factors. Future research should focus on addressing the safety and stability of catalysts, developing green and efficient modification methods, enhancing degradation efficiency, and implementing large-scale treatment of real wastewater. This work offers insights into the resource utilization of metallurgical slags and pollutant degradation in wastewater.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Águas Residuárias , Cobre , Substâncias Perigosas , Metalurgia , Oxirredução , Poluentes Químicos da Água/análise
10.
J Biomed Mater Res B Appl Biomater ; 112(1): e35338, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37846459

RESUMO

Titanium and its alloys are used to make dental implants because of its low density, high strength, and corrosion resistance. This paper describes the development of a potential biomaterial Ti-10Nb by powder metallurgy utilizing four different compaction pressures and analyses its microstructural, physical, mechanical, electrochemical, biological, and tribological behavior under various situations. The alloys were fabricated using four different compaction pressures, that is, 600, 650, 700, and 750 MPa, and sintered in a vacuum atmosphere at 1000°C for 1.5 h. The density of the samples was measured using Archimedes principle. X-ray diffraction and scanning electron microscopy equipped with energy dispersive spectroscopy were used to investigate the phase composition and microstructure, and a profilometer was used to examine the surface roughness of various samples. Vickers hardness tester was used to evaluate hardness, and a universal testing machine was used for compression testing. Corrosion and wear behavior were examined using a potentiostat and a Bio-Tribometer, respectively. This Ti-10Nb alloys consist of α + ß phase, and have 16% highest porosity in sample compacted at 600 MPa. The samples compacted at 750 MPa achieved highest hardness, yield strength, compressive strength, and elastic modulus of 450 ± 29.72 HV, 718.22 ± 16.37 MPa, 1543.59 ± 24.37 MPa, and 41.27 ± 3.29 GPa, respectively. In addition, it also possesses highest corrosion and wear resistance with lowest icorr of 0.3954 ± 0.008 µA/cm2 and wear volume of (31.25 ± 0.206) × 10-3 mm3 . These results indicate that the developed alloys have a variety of desirable properties, including high hardness, adequate compressive strength, good corrosion and wear resistance, apatite-forming capability, and a low elastic modulus, which is advantageous for avoiding stress shielding. Therefore, it may be recommended to use it as a dental implant material.


Assuntos
Ligas , Titânio , Ligas/química , Titânio/química , Pós , Materiais Biocompatíveis , Corrosão , Metalurgia , Teste de Materiais
11.
Int J Environ Health Res ; 34(2): 1044-1052, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36970880

RESUMO

The incidence of DNA damage from exposure to specific types of metalworking fluids has been reported. In this research, size-selective permissible limits to prevent genotoxic damage in A549 cell lines exposed to two types of mineral oil were estimated for the first time using a benchmark dose approach and extrapolated to workers. The comet assay was performed based on Olive and Banath protocol to determine DNA damage. Then, the Benchmark Dose, the 95% lower bound confidence limit BMD, and the 95% upper-bound confidence limit BMD were determined using continuous response data. Finally, the four Benchmark Dose levels reported in the A549 cell line were extrapolated to the human population in occupational settings in two phases. This study showed when determining the permissible limits, the type used or unused, the type of injury, the organ affected in the body and the size of the particles should also be considered.


Assuntos
Poluentes Ocupacionais do Ar , Exposição Ocupacional , Humanos , Exposição Ocupacional/análise , Óleo Mineral/toxicidade , Metalurgia , Dano ao DNA
12.
Int Arch Occup Environ Health ; 97(1): 57-64, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38070038

RESUMO

OBJECTIVE: The relationship between metalworking fluids (MWFs) and nonalcoholic fatty liver disease (NAFLD) has not been previously explored. We aim to investigate the relationship between occupational exposure to MWFs and the prevalence of NAFLD and to determine the cumulative exposure threshold per day. METHODS: In 2020, 2079 employees were selected randomly from one computer numerical control machining factory in Wuxi for a questionnaire survey, and occupational health examinations were conducted at the affiliated branch of Wuxi Eighth People's Hospital. MWF samples were collected within the factory using the National Institute for Occupational Safety and Health (NIOSH) 5524 method. NAFLD was defined as having a hepatic steatosis index (HSI) ≥ 36 without significant alcohol consumption. The relationship between NAFLD and MWFs was analyzed using logistic regression, and the daily exposure threshold was calculated using R software. RESULTS: MWF exposure was found to be a risk factor for NAFLD in exposed workers compared to the non-exposed group. The OR for NAFLD in workers exposed to MWFs compared to controls was 1.42 (95% CI: 1.04-1.95). An increased risk of NAFLD was shown to be associated with an increasing dose. The daily exposure dose threshold to MWFs was found to be 6.54 mg/m3 (OR = 2.09, 95% CI: 1.24-3.52). CONCLUSION: An association between occupational exposure to MWFs and NAFLD was found. As the concentration of exposure rose, the prevalence of NAFLD was also escalated.


Assuntos
Poluentes Ocupacionais do Ar , Hepatopatia Gordurosa não Alcoólica , Exposição Ocupacional , Humanos , Poluentes Ocupacionais do Ar/análise , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Metalurgia , Exposição Ocupacional/análise , Fatores de Risco
14.
J Environ Manage ; 350: 119649, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38007928

RESUMO

A profound green transformation of China's heavy industrial aggregation regions is required to conquer severe air pollution, and fulfill carbon peak pledge. Here, to clarify the coordinated mechanism and an optimal roadmap for the reduction of CO2 and gaseous pollutants, we integrated input-output modelling, system dynamics, and multi-objective programming to construct a CO2 and gaseous pollutants synergistic reduction model initially; investigated incentive approaches from 2020 to 2035; Hebei, with the largest steel production in China, was adopted as a demonstrative region. Results revealed that intensive dual control of efficiency and structure in energy and industry can accelerate achieving carbon peak in 2029. In optimal case, CO2 emission intensity can reach a 75.2% reduction compared to 2020, and gaseous pollutants continue decline simultaneously (SO2 and NOx can drop by 63% and 48%); and the synergistic reduction level is expected to improve. Thus, vigorously develop decoupling between economy-air pollution-carbon reduction in Hebei. As opposed to efficiency improvement, structural adjustments were demonstrated to be more effective than short-term efficiency improvements. In addition, the estimated development potential of traditional heavy industries such as steel and petrochemicals is limited, whereas the equipment manufacturing industry, closely linked to traditional industries, is expected to continue its development. Furthermore, although in the electrification process, coal consumption is still needed because of its indispensable role in the production process of heavy industries. The results can facilitate policy-making for heavy industrial aggregation areas' green transformation in shaping policies and actions with clear objectives, effective measures, and sound coordination.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Gases , China , Metalurgia , Carbono , Aço
15.
PLoS One ; 18(12): e0294569, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38113240

RESUMO

Metalwork was a major technological innovation that displaced stone-tool technologies and transformed human society and the environment. However, our understanding of these processes remains partial. In this paper, we approach the stone-to-metal transition from a novel angle-the presence of flint knapping at metal production sites. Drawing on excavations at the Late Bronze and Iron Age copper smelting sites in Timna Valley, Israel, we demonstrate that systematic production of expedient stone tools was integral to these sites' industrial operations, placing it at the heart of the very same metal circulation networks that were presumably responsible for its displacement. The observations from Timna, coupled with evidence for the use of chipped stone technology in other early Iron Age metallurgical contexts, support the hypothesis that it was probably both the high accessibility of iron and its qualities that put an end to the stone tool industry. Copper and bronze could not easily fulfill the function of the ad hoc stone tools and were not used to replace stone tools even if they were available and accessible.


Assuntos
Arqueologia , Cobre , Humanos , Israel , Tecnologia , Metalurgia
16.
Environ Geochem Health ; 46(1): 12, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38147164

RESUMO

To conduct a precise health risk assessment of heavy metals (HMs) in soil, it is imperative to ascertain the primary sources of potential health risks. In this study, we conducted comprehensive measurements of HMs, specifically focusing on the accumulation of Cu, Cd, Sb, Zn, and Pb in local soil, which may pose threats to environmental quality. To achieve our objective, we employed a method that combines positive matrix factorization with a health risk assessment model to quantify the health risks associated with specific sources. The results obtained from the geo-accumulation index indicate that the majority of HMs found in the local soil are influenced by anthropogenic activities. Among these sources, local industrial-related activities contributed the largest proportion of HMs to the soil at 34.7%, followed by natural sources at 28.7%, mining and metallurgy-related activities at 28.2%, and traffic-related activities at 8.40%. Although the non-carcinogenic and carcinogenic risks associated with individual HMs were found to be below safety thresholds, the cumulative health risks stemming from total HMs exceeded safety limits for children. Moreover, the unacceptable health risks for children originating from industrial-related activities, natural sources, and mining and metallurgy-related activities were primarily concentrated in proximity to mining sites and industrial areas within the local region. This investigation furnishes valuable insights that can aid governmental authorities in formulating precise control policies to mitigate health threats posed by soils in polymetallic mining areas.


Assuntos
Metalurgia , Metais Pesados , Criança , Humanos , China , Metais Pesados/toxicidade , Medição de Risco , Solo
17.
Environ Sci Pollut Res Int ; 30(57): 119627-119653, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37962753

RESUMO

Metallurgy is pivotal for societal progress, yet it yields wastewater laden with hazardous compounds. Adhering to stringent environmental mandates, the scientific and industrial sectors are actively researching resilient treatment and disposal solutions for metallurgical effluents. The primary origins of organic pollutants within the metallurgical sector include processes such as coke quenching, steel rolling, solvent extraction, and electroplating. This article provides a detailed analysis of strategies for treating steel industry waste in wastewater treatment. Recent advancements in membrane technologies, adsorption, and various other processes for removing hazardous pollutants from steel industrial wastewater are comprehensively reviewed. The literature review reveals that advanced oxidation processes (AOPs) demonstrate superior effectiveness in eliminating persistent contaminants. However, the major challenges to their industrial-scale implementation are their cost and scalability. Additionally, it was discovered that employing a series of biological reactors instead of single-step biological processes enhances command over microbial communities and operating variables, thus boosting the efficacy of the treatment mechanism (e.g., achieving a chemical oxygen demand (COD) elimination rate of over 90%). This review seeks to conduct an in-depth examination of the current state of treating metallurgical wastewater, with a particular emphasis on strategies for pollutant removal. These pollutants exhibit distinct features influenced by the technologies and workflows unique to their respective processes, including factors such as their composition, physicochemical properties, and concentrations. Therefore, it is of utmost importance for customized treatment and disposal approaches, which are the central focus of this review. In this context, we will explore these methods, highlighting their advantages and characteristics.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Resíduos Industriais/análise , Metalurgia , Aço
18.
PLoS One ; 18(10): e0289771, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37856549

RESUMO

This paper discusses the use of "legacy data" in research on Roman Period iron smelting in the territory of the Przeworsk Culture in Magna Germania. The dataset includes results of 240 analyses of smelting slag and iron ores chemistry. A majority of these analyses were conducted in the 1950s-1980s. The quality of these data is far below present-day standards. Only major elements were reported, analytical methods were often not specified (although optical emission spectroscopy and wet chemical analyses can be assumed in such cases) and information on detection limits, precision and accuracy of the results is missing. In spite of this, a Principal Component Analysis-Agglomerative Hierarchical Clustering treatment successfully isolated observations from the three main iron smelting regions of the Przeworsk Culture (the Holy Cross Mountains, Masovia and Silesia). These results to a degree confirm a theory proposed in the 1960s by J. Piaskowski, according to whom it was possible to distinguish iron produced in the Holy Cross Mountains from the iron produced elsewhere in the territory of what is now Poland on the basis of metal characteristics. These findings will pave the way to the ongoing research project on the Przeworsk Culture metallurgy. It is also argued that, apart from a search for new methods in iron provenance studies, more attention should be paid to results of earlier analyses and to a compilation of legacy databases. The other result is an open and flexible Agglomerative Hierarchical Clustering R code to examine discrimination between production areas and to propose artefact provenance patterns in a convenient interactive way using the R development environment.


Assuntos
Ferro , Metais , Ferro/química , Metalurgia , Polônia , Artefatos
20.
Sci Rep ; 13(1): 14954, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37737292

RESUMO

Since February 2022, the full-scale war in Ukraine has been strongly affecting society and economy in Ukraine and beyond. Satellite observations are crucial tools to objectively monitor and assess the impacts of the war. We combine satellite-based tropospheric nitrogen dioxide (NO2) and carbon dioxide (CO2) observations to detect and characterize changes in human activities, as both are linked to fossil fuel combustion processes. We show significantly reduced NO2 levels over the major Ukrainian cities, power plants and industrial areas: the NO2 concentrations in the second quarter of 2022 were 15-46% lower than the same quarter during the reference period 2018-2021, which is well below the typical year-to-year variability (5-15%). In the Ukrainian capital Kyiv, the NO2 tropospheric column monthly average in April 2022 was almost 60% smaller than 2019 and 2021, and about 40% smaller than 2020 (the period mostly affected by the COVID-19 restrictions). Such a decrease is consistent with the essential reduction in population and corresponding emissions from the transport and commercial/residential sectors over the major Ukrainian cities. The NO2 reductions observed in the industrial regions of eastern Ukraine reflect the decline in the Ukrainian industrial production during the war (40-50% lower than in 2021), especially from the metallurgic and chemical industry, which also led to a decrease in power demand and corresponding electricity production by thermal power plants (which was 35% lower in 2022 compared to 2021). Satellite observations of land properties and thermal anomalies indicate an anomalous distribution of fire detections along the front line, which are attributable to shelling or other intentional fires, rather than the typical homogeneously distributed fires related to crop harvesting. The results provide timely insights into the impacts of the ongoing war on the Ukrainian society and illustrate how the synergic use of satellite observations from multiple platforms can be useful in monitoring significant societal changes. Satellite-based observations can mitigate the lack of monitoring capability during war and conflicts and enable the fast assessment of sudden changes in air pollutants and other relevant parameters.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Dióxido de Nitrogênio , Ucrânia , Metalurgia , Fatores Socioeconômicos
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