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1.
Curr Biol ; 34(6): 1341-1348.e3, 2024 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-38460511

RESUMO

Restoration is increasingly seen as a necessary tool to reverse ecological decline across terrestrial and marine ecosystems.1,2 Considering the unprecedented loss of coral cover and associated reef ecosystem services, active coral restoration is gaining traction in local management strategies and has recently seen major increases in scale. However, the extent to which coral restoration may restore key reef functions is poorly understood.3,4 Carbonate budgets, defined as the balance between calcium carbonate production and erosion, influence a reef's ability to provide important geo-ecological functions including structural complexity, reef framework production, and vertical accretion.5 Here we present the first assessment of reef carbonate budget trajectories at restoration sites. The study was conducted at one of the world's largest coral restoration programs, which transplants healthy coral fragments onto hexagonal metal frames to consolidate degraded rubble fields.6 Within 4 years, fast coral growth supports a rapid recovery of coral cover (from 17% ± 2% to 56% ± 4%), substrate rugosity (from 1.3 ± 0.1 to 1.7 ± 0.1) and carbonate production (from 7.2 ± 1.6 to 20.7 ± 2.2 kg m-2 yr-1). Four years after coral transplantation, net carbonate budgets have tripled and are indistinguishable from healthy control sites (19.1 ± 3.1 and 18.7 ± 2.2 kg m-2 yr-1, respectively). However, taxa-level contributions to carbonate production differ between restored and healthy reefs due to the preferential use of branching corals for transplantation. While longer observation times are necessary to observe any self-organization ability of restored reefs (natural recruitment, resilience to thermal stress), we demonstrate the potential of large-scale, well-managed coral restoration projects to recover important ecosystem functions within only 4 years.


Assuntos
Antozoários , Animais , Antozoários/metabolismo , Ecossistema , Recifes de Corais , Carbonatos/metabolismo , Carbonato de Cálcio
2.
Appl Microbiol Biotechnol ; 108(1): 202, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349550

RESUMO

Aureobasidium is omnipresent and can be isolated from air, water bodies, soil, wood, and other plant materials, as well as inorganic materials such as rocks and marble. A total of 32 species of this fungal genus have been identified at the level of DNA, of which Aureobasidium pullulans is best known. Aureobasidium is of interest for a sustainable economy because it can be used to produce a wide variety of compounds, including enzymes, polysaccharides, and biosurfactants. Moreover, it can be used to promote plant growth and protect wood and crops. To this end, Aureobasidium cells adhere to wood or plants by producing extracellular polysaccharides, thereby forming a biofilm. This biofilm provides a sustainable alternative to petrol-based coatings and toxic chemicals. This and the fact that Aureobasidium biofilms have the potential of self-repair make them a potential engineered living material avant la lettre. KEY POINTS: •Aureobasidium produces products of interest to the industry •Aureobasidium can stimulate plant growth and protect crops •Biofinish of A. pullulans is a sustainable alternative to petrol-based coatings •Aureobasidium biofilms have the potential to function as engineered living materials.


Assuntos
Aureobasidium , Biofilmes , Carbonato de Cálcio , Produtos Agrícolas , Gasolina
3.
Chemosphere ; 353: 141503, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382718

RESUMO

Recently, water contamination caused by the misuse of antibiotics has become a growing concern. In this study, an economical chitin/calcite composite (CCA) was extracted from crab shell waste, and the effects and mechanisms of its removal of ciprofloxacin (CIP) and tetracycline (TC) from aqueous solution were investigated. The functional groups of chitin and the metal phase of calcite gave CCA the ability to remove antibiotics. Experiments on kinetics, isothermal adsorption, thermodynamics, co-removal, and reusability were conducted to systematically explore the adsorption performances of CCA toward antibiotics. The pseudo-second-order (FSO) and Langmuir models suited the data obtained from experiments best and displayed a good fit for the chemisorption and a certain homogeneity of adsorption sites. At 25 °C, the maximum adsorption capacities (Qmax) toward CIP and TC were 228.86 and 150.76 mg g-1, respectively. The adsorption mechanisms of CCA with TC and CIP are pH dependent since pH can affect the surface charge of CCA and the form in which CIP and TC are existing. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) demonstrated that the keto-O and carboxyl groups of CIP and the carbonyl, hydroxyl, and amido groups of TC could be responsible for the binding with the calcite and the functional groups of chitin through surface complexation, cation bridge and hydrogen bonding.


Assuntos
Ciprofloxacina , Poluentes Químicos da Água , Ciprofloxacina/química , Carbonato de Cálcio , Quitina , Antibacterianos/química , Tetraciclina/química , Poluentes Químicos da Água/análise , Adsorção , Cinética , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Environ Sci Pollut Res Int ; 30(54): 115870-115881, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37897576

RESUMO

Artificial light at night (ALAN) is a growing environmental hazard with economic, ecological, and public health implications. Previous studies suggested a higher burden of light pollution and related adverse effects in disadvantaged communities. It is critical to characterize the geographic distribution and temporal trend of ALAN and identify associated demographic and socioeconomic factors at the population level to lay the foundation for environmental and public health monitoring and policy-making. We used satellite data from the Black Marble suite to characterize ALAN in all counties in contiguous US and reported considerable variations in ALAN spatiotemporal patterns between 2012 and 2019. As expected, ALAN levels were generally higher in metropolitan and coastal areas; however, several rural counties in Texas experienced remarkable increase in ALAN since 2012, while population-level ALAN burden also increased substantially in many metropolitan areas. Importantly, we found that during this period, although the overall ALAN levels in the USA declined modestly, the temporal trend of ALAN varied across areas with different racial/ethnic compositions: counties with a higher percentage of racial/ethnic minority groups, particularly Hispanic populations, exhibited significantly less decline. As a result, the differences in ALAN levels, as measured by the Black Marble product, across racial/ethnic groups became larger between 2012 and 2019. In conclusion, our study documented variations in ALAN spatiotemporal patterns across America and identified multiple population correlates of ALAN patterns that warrant further investigations. Future studies should identify underlying factors (e.g., economic development and decline, urban planning, and transition to newer lighting technologies such as light emitting diodes) that may have contributed to ALAN disparities in the USA.


Assuntos
Etnicidade , Poluição Luminosa , Humanos , Justiça Ambiental , Grupos Minoritários , Carbonato de Cálcio
5.
Appl Environ Microbiol ; 89(8): e0179422, 2023 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-37439668

RESUMO

Current production of traditional concrete requires enormous energy investment that accounts for approximately 5 to 8% of the world's annual CO2 production. Biocement is a building material that is already in industrial use and has the potential to rival traditional concrete as a more convenient and more environmentally friendly alternative. Biocement relies on biological structures (enzymes, cells, and/or cellular superstructures) to mineralize and bind particles in aggregate materials (e.g., sand and soil particles). Sporosarcina pasteurii is a workhorse organism for biocementation, but most research to date has focused on S. pasteurii as a building material rather than a biological system. In this review, we synthesize available materials science, microbiology, biochemistry, and cell biology evidence regarding biological CaCO3 precipitation and the role of microbes in microbially induced calcium carbonate precipitation (MICP) with a focus on S. pasteurii. Based on the available information, we provide a model that describes the molecular and cellular processes involved in converting feedstock material (urea and Ca2+) into cement. The model provides a foundational framework that we use to highlight particular targets for researchers as they proceed into optimizing the biology of MICP for biocement production.


Assuntos
Carbonato de Cálcio , Conservação de Recursos Energéticos , Microbiologia Industrial , Sporosarcina , Compostos de Amônio/metabolismo , Carbonato de Cálcio/economia , Carbonato de Cálcio/metabolismo , Precipitação Química , Sporosarcina/citologia , Sporosarcina/metabolismo , Ureia/metabolismo
6.
Environ Monit Assess ; 195(8): 1007, 2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37515672

RESUMO

Land elevation exerts a significant influence on soil fertility through affecting macro and micro climatic conditions and geomorphological processes. To evaluate the soil fertility at different elevation classes, namely 1600-2000, 2000-2400, 2400-2800, and > 2800 m, 350 surface soil samples (0-30 cm) were collected from the agricultural lands of northwestern Iran. Soil properties, including soil texture, calcium carbonate (CaCO3), pH, electrical conductivity (EC), organic matter (OM), and soil macronutrients (TN, P, and K) and micronutrients (Fe, Mn, Zn, and Cu), were measured. Finally, the interpretation and classification of the soil samples were made using the nutritional value index (NIV). The comparison of the NIV index based on elevation changes showed that the Gomez method classifies the soil properties in an optimal order as evidenced by its tendency towards the center of the data. However, the Common method is more consistent with the observed trend. After classifying the NIV index using the Common method, it was determined that CaCO3 and soil salinity are not the limiting factor for soil fertility in different elevation classes. However, in all elevations, high pH, low OM at elevations > 2800 m, total nitrogen (TN), available phosphorous (AP), and micronutrients deficiencies, except Zn at the elevation of 1600-2000 m, are the main limiting factors for soil fertility of agricultural lands. The results provide further insight into the elevation-based land evaluation and may supports grower's decision on nutrient management and crop selection strategies.


Assuntos
Monitoramento Ambiental , Solo , Solo/química , Irã (Geográfico) , Micronutrientes/análise , Agricultura , Fósforo/análise , Metais/análise , Carbonato de Cálcio/análise
7.
Environ Res ; 233: 116474, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37352953

RESUMO

Soil conditioner is class of products used to enhance physics, physicochemical or soil biological activities, being able to recover disturbed or nutritional unbalanced soils. The formulation of a soil conditioner composed by bauxite residue (BR), and organic oil palm wastes, as raw materials, was recently proposed as an innovative strategy for the Brazilian acid soils amendment. Here we show the results of soil conditioner amended soil leaching tests and agronomical performance. The soil conditioners were formulated by BR mixed with decomposed POC (palm oil compost) and non-decomposed POMW (palm oil mill waste) oil palm wastes, in the proportion of 25% BR + 75% POC (T1) and 50% BR + 50% POMW (T2), in addition to the treatment with 100% POMW without BR (T3) and limestone at a dose calculated to raise soil pH to 6.0 (T4). Except for T4, all conditioners were applied to the soil at doses of 40, 80, and 120 t ha-1 for leaching tests. The experimental plots were composed of polyvinyl chloride columns, filled with 5 kg of soil, with bottles adapted with hoses at the bottom to facilitate drainage of the leachate. After leaching tests, the respective columns were used as pots for the cultivation of Brachiaria grass, stage with addition of a control composed by undisturbed soil (T5). The pH of the leachates had changes, but the use of BR associated with POMW was similar to the use of limestone. Of the 65 chemical elements evaluated, only nine were identified in the leachate, being most of them considered as plant nutrients. As for soil pH, limestone was slightly higher (6.6) than treatments that had BR (5.5). Brachiaria grass cultivated in the soil amended with conditioners showed similar results of limestone treated soil for the parameters of plant development and showed fertility improvement.


Assuntos
Poluentes do Solo , Solo , Solo/química , Óxido de Alumínio , Óleo de Palmeira , Agricultura/métodos , Poaceae , Poluentes do Solo/análise , Carbonato de Cálcio
8.
Environ Monit Assess ; 195(6): 673, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37188758

RESUMO

The objective of this research is to assess the impact of radon concentration on workers at certain construction material industries in Erbil, Kurdistan Region of Iraq. The CR-39 solid-state track detector was used in this experiment to monitor radon levels and their daughters. For this purpose, as a case study group, 70 workers were divided into seven subgroups (gypsum, cement plant, lightweight block, marble, red brick 1, crusher stone, and concrete block 2), and 20 healthy volunteers were selected as a control group. The findings demonstrate that the mean concentrations of radon, radium, uranium, and radon daughters deposited on the detector face (POS) and chamber walls (POW) for the case study group were 9.61 ± 1.52 Bq/m3, 0.33 ± 0.05 Bq/Kg, 5.39 ± 0.86 mBq/Kg, 4 ± 0.63, and 16.62 ± 2.64 mBq/m3, whereas for the control group, they were 3.39 ± 0.58 Bq/m3, 0.117 ± 0.03 Bq/Kg, 1.91 ± 0.32 mBq/Kg, 1.41 ± 0.24, and 5.88 ± 1 mBq/m3, respectively. The statistical analysis revealed that radon, radium, uranium, and POW and POS concentrations were statistically significant (p ≤ 0.001) in the samples for the case study groups of cement, lightweight block, red brick 1, marble, and crusher stone factories in comparison to the control group; however, the results for gypsum and concrete block 2 factories were not statistically significant in comparison to the control group. Intriguingly, the radon levels in every blood sample examined were far lower than the 200 Bq/m3 limit established by the International Atomic Energy Agency. Hence, it may be argued that the blood is devoid of contaminants. These results are crucial for determining whether or not an individual is exposed to substantial quantities of radiation and for demonstrating a link between radon, its daughter, uranium, and the prevalence of cancer among workers in the Kurdish region of Iraq.


Assuntos
Poluentes Radioativos do Ar , Monitoramento de Radiação , Rádio (Elemento) , Radônio , Urânio , Humanos , Rádio (Elemento)/análise , Urânio/análise , Sulfato de Cálcio/análise , Monitoramento Ambiental , Radônio/análise , Poluentes Radioativos do Ar/análise , Materiais de Construção/análise , Carbonato de Cálcio/análise , Monitoramento de Radiação/métodos
9.
Environ Pollut ; 332: 121665, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37080520

RESUMO

Biogenic calcium carbonate (bio-CaCO3) cementing tailings is an efficient technology to immobilize heavy metals in waste tailings. However, the underlying mechanism of interface cementation has not yet been clearly established, which limits the technological development. In this study, we used advanced techniques, including atomic force microscopy-based Lorentz contact resonance (AFM-LCR) spectroscopy, AFM-based nanoscale infrared (AFM-IR) spectroscopy, and solid-state nuclear magnetic resonance (ssNMR) spectroscopy, to reveal the structural, mechanical, and chemical properties of the interface on the nanoscale. Ureolytic bacteria produced bio-CaCO3 to fill in pore space and to bind cement tailings particles, which prevented the formation of leachate containing heavy metals. After cementation, a strong 40-300 nm thin interface was formed between the taillings and bio-CaCO3 particles. Unlike chemically synthesized CaCO3, bio-CaCO3 is strongly negatively charged, which gives it better adhesion ability. Fourier transform infrared (FTIR), AFM-IR, and 29Si ssNMR spectra indicated that the Si-OH and Si-O-Si groups on the silicate surface were converted to deprotonated silanol groups (≡Si-O-) at a high pH and they formed strong chemical bonds of Si-O-Ca on the interface through a Ca ion bridge. In addition, hydrogen bonding with Si-OH also played a role at the cementation interface. These findings provide the nano-scale interfacial structure and mechanism of bio-CaCO3 cementing silicate tailings and accelerate the development of tailings disposal technology.


Assuntos
Carbonato de Cálcio , Metais Pesados , Carbonato de Cálcio/química , Cimentação , Silicatos/química
10.
Mar Pollut Bull ; 189: 114826, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36931156

RESUMO

Ocean acidification has emerged as a major challenge affecting the development of the marine aquaculture. Seasonal variations of seawater pH and aragonite saturation (Ωarag) were investigated in the Muping Marine Ranch, Yantai. The results showed that the seasonal variations of pH and Ωarag were distinct. The temperature exerted opposite effects on pH and Ωarag and played a dominant role in pH variation, while limited role in Ωarag. The air-sea exchange had a syntropic effect on pH and Ωarag but less impact on their seasonal variations. Biological activities affected seasonal variations of surface seawater pH and Ωarag, but they largely canceled each other out with other non-temperature effects; while bottom seawater Ωarag was mainly controlled by biological respiration in summer. This study demonstrates that pH is primarily controlled by seasonal temperature changes, whereas Ωarag would be a better indicator for ocean acidification caused by non-temperature processes.


Assuntos
Carbonato de Cálcio , Água do Mar , Concentração de Íons de Hidrogênio , Estações do Ano , Carbonato de Cálcio/análise , China , Dióxido de Carbono/análise
11.
Environ Monit Assess ; 195(3): 375, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36757458

RESUMO

This study presents the assessment of the air, soil, and water quality within the residential communities around two passive limestone mining/cement factories. The associations between the pollutants were tested across the media, within each medium, between the layers, and between two groups of the communities. The mean values for the PM1.0, PM2.5, and PM10 were 65.8 µgm-3, 50.1, and 73.7, respectively, in the air; for the Mn, Fe, Cu, Zn, Cr, K-40, U-238, and Th-232 were 0.433 g/kg, 8.950, 0.005, 0.054, 0.104, 161.57 Bq. kg-1, 61.10, and 15.85, respectively, in the topsoil; 0.365 g/kg, 8.259, 0.004, 0.029, 0.057, 71.84 Bq. kg-1, 16.37, 4.66, respectively, in the subsoil; and for the Mn, Fe, and Zn were 0.190, 1.499, and 0.256 mg/l, respectively, in the water. The PM10, Fe, and K-40 were the most abundant pollutants. The Co and Mn, Zn and Cu, Fe and Cu, the absorbed dose rate (ADR) and K-40, and ADR and U-238 correlated significantly. Though the Ibese group was more polluted than the Ewekoro group, the generally low levels of the pollutions were confirmatory of the earlier suspicions of the mining/production activities. The 2nd lithological layer at 0.5 to 1.9 m depths or the 3rd lithological layer at 1.1 to 7.69 m depths for the Ibese group and the 1st layer at the surface or the 2nd layer at 0.5 m depth for the Ewekoro group are protective layers for the groundwater that must not be exploited, given the three classes of groundwater vulnerability indices observed in the area.


Assuntos
Poluentes Ambientais , Metais Pesados , Poluentes do Solo , Urânio , Carbonato de Cálcio , Monitoramento Ambiental , Metais Pesados/análise , Medição de Risco , Poluentes do Solo/análise
12.
Environ Sci Pollut Res Int ; 30(13): 38443-38464, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36580240

RESUMO

More than half of the CO2 emissions during the manufacturing of ordinary Portland cement (OPC) occur due to the calcination of calcium carbonate in addition to burning of fossil fuel to power the process. Consequently, there is a concerted effort to decrease the carbon footprint associated with this process, by minimizing the use of OPC. In line with this trend, an attempt was made in the reported study to synthesize a novel alkali-activated binder using CaCO3-rich waste limestone powder (WLSP) as a precursor. Utilizing the Taguchi method, four important parameters were varied at three levels to optimize the alkali-activated mixture. Analysis of variance (ANOVA) of the obtained results was performed to assess the impact of each of the factors on the properties of the developed binder. To enhance the strength further, OPC was added as a partial replacement of WLSP. The binder was characterized using scanning electron microscopy. The results have indicated that alkaline activator to binder ratio, Na2SiO3 to NaOH ratio, and sand to binder ratio of 0.575, 1.57, and 2.5, respectively, were the optimum to obtain satisfactory strength and workability with a 13.7-M NaOH activator solution. The incorporation of a small quantity of OPC in the mixture remarkably improved the density and strength of the alkali-activated-WLSP binder. Pirssonite (CaCO3.Na2CO3.2H2O) and C/N-A-S-H were the dominant mineral phases formed in the developed binder, particularly in the ones alkali-activated WLSP/OPC. In addition, the eco-efficiency assessment revealed that the WLSP is a promising low-carbon binder that can be used in developing more sustainable alkali-activated binder. The results have shown that the WLSP can be potentially utilized in developing binder that can be potentially used in the structural applications.


Assuntos
Álcalis , Carbonato de Cálcio , Análise de Variância , Pós , Hidróxido de Sódio
13.
Waste Manag ; 155: 311-319, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36410148

RESUMO

Meeting the current demand for concrete requires not only mining tons of gravel and sand, but also burning large amounts of fossil fuel resources in cement kilning. Consequently, concrete recycling is crucial to achieving a material-efficient society, especially with the application of various categories of concrete and the goal of phasing out fossil fuels. A comparative life cycle assessment (LCA) is used to assess the engineering material footprint (EMF) and the fossil fuel material footprint (FMF) in closed-loop recycling of three types of concrete: siliceous concrete, limestone concrete, and lightweight aggregate concrete. This study aims to investigate the impact of (i) concrete categories, (ii) methods to model recycling, and (iii) using renewable energy sources on the material footprint in concrete recycling. The results highlight that the concrete recycling system can reduce 99% of the EMF and 66-93% of the FMF compared with the baseline system, in which concrete waste is landfilled. All three recycling modeling approaches indicate that concrete recycling can considerably reduce EMF and FMF compared with the baseline system, primarily resulting from the displacement of virgin raw materials. Using alternative diesels is more sensitive than adopting renewable electricity in reduction of the FMF in concrete recycling. Replacing diesel with electrolysis- and coal-based synthetic diesel for concrete recycling could even increase the FMF, while using biodiesel made from rapeseed and wood-based synthetic diesel can reduce 47-51% and 84-89% of the FMF, respectively, compared to the virgin diesel-based recycling system. Finally, we discussed the multifunctionality and rebound effects of recycling, and double-counting risk in material and energy accounting.


Assuntos
Combustíveis Fósseis , Reciclagem , Animais , Biocombustíveis , Carbonato de Cálcio , Estágios do Ciclo de Vida
14.
Water Res ; 228(Pt B): 119369, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36434975

RESUMO

Eutrophication and the predicted limited future availability of rock phosphate has triggered the increased development of phosphorus (P) recovery technologies, however, for remote regions, recovery solutions are still limited. Here, we report on a novel pilot-scale technology (FILTRAFLOTM-P reactor) to recover phosphate (PO43-) from wastewater effluent through a filtration/adsorption process in a rural setting. This unit employs enhanced gravitational filtration through adsorption media (here, a novel KOH deacetylated crab carapace based chitosan-calcite material (CCM)) with continuous self-backwashing. Trials were designed to assess how the FILTRAFLOTM-P unit would operate under 'real' conditions (both at low and high PO43- levels), and to ascertain the effectiveness of the adsorbent to recover phosphate from final effluent. High removal was achieved at low phosphate concentrations, bringing the residual effluent PO43- level below 1 mg/L (EU limit for sensitive water bodies), while phosphate was efficiently harvested (at more than 50%) at higher PO43- levels. Surface microprecipitation and inner-sphere complexation were postulated as the main PO43- adsorption mechanisms through XRD, XPS and EDX elemental mapping. Further, a quality assessment of the P-enriched CCM (which could be used as a potential soil amendment) was undertaken to consider elemental composition, microbiological assessment and quantification of organic micropollutants. Quality analysis indicated ∼2.5% P2O5 present, trace levels (well below legislative limits) of heavy metals and extremely low levels of organic pollutants (e.g., PCBs, pharmaceuticals). No detectable levels of target bacterial pathogens were observed. Pot trials showed that ryegrass cultivated with the addition of the CCM adsorbent achieved higher plant dry matter and P concentration when compared to unfertilised controls, with a slow-release kinetic pattern. This study showed that CCM used with the FILTRAFLOTM-P pilot reactor has high potential to recover phosphate from effluents and encourage resource recovery via bio-based management of waste.


Assuntos
Quitosana , Fosfatos , Fertilizantes , Águas Residuárias , Fósforo , Carbonato de Cálcio
15.
Environ Sci Pollut Res Int ; 30(10): 25382-25401, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35836050

RESUMO

Health monitoring of structures using techniques based on the smart material is an innovative concept that is exploding technological revolutions in the field of civil engineering. The electro-mechanical impedance (EMI) technique is used for structural health monitoring (SHM) and to investigate the damages in the structures. The bacterial incorporation in concrete produces calcite material through metabolism process in presence of moisture and carbon dioxide, which improves the mechanical properties of concrete. Hence, its application in construction of the buildings will improve the health of structures. In this research paper, dynamic behaviour of the bacterial concrete was investigated numerically. The beams of size 700 × 150 × 150 mm of bacterial concrete and control concrete were modelled using finite element-based package ANSYS19. The beam of bacterial concrete was simulated as per the characteristics of the materials produced after the bacterial metabolism reactions. The EMI technique was applied to investigate the health of these beams. Admittance (conductance and susceptance) signatures were determined using piezo-ceramic lead zirconate titanate (PZT) sensors installed at mid-point on the top surface of concrete beams. The beams were exposed to dynamic loading and the intensity of dynamic loading was increased in four sub-steps. For the quantification of strength development in the concrete beam, the root mean square deviation (RMSD) statistical index had been applied. It was observed that the bacterial concrete beam has more resistance to the dynamic loading.


Assuntos
Carbonato de Cálcio , Dióxido de Carbono , Impedância Elétrica , Cerâmica , Tecnologia
16.
Sci Total Environ ; 860: 160454, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36436624

RESUMO

Evaluating the ecological health risks created by major ions, metalloids and trace elements concentrations in groundwater and pollution sources were essential to effectively protect groundwater resources. For this study, A total of 93 samples were collected from multiple aquifers in the Sunan mining area, eastern China. The Positive matrix factorization (PMF) model results revealed the following sources, in percentages. The Quaternary loose aquifer (QLA) water includes CaMg mineral dissolution (30.3 %), salinity (28.2 %), metal industrial wastewater (26.3 %), iron and manganese minerals (8.0 %) and coal gangue (7.2 %). The Permian fractured sandstone aquifer (PFA) water includes CaMg mineral dissolution sources (29.8 %), mine wastewater (28.6 %), aluminosilicate (21.6 %) and pyrite source (20.0 %). The Carbonifer fractured limestone aquifer (CFA) water includes and mine wastewater (34.2 %), CaMg mineral dissolution (25.4 %), pyrite (22.6 %) and aluminosilicate (17.7 %). The Ordovician fractured limestone aquifer (OFA) water includes manganese and aluminum metal minerals (27.9 %), halite dissolution materials (24.9 %), industrial and agricultural waste water (24.0 %) and calcium­magnesium minerals (23.2 %). A PMF-based assessment of ecological health risk indicates that the concentrations of elements As and Co are the dominant elements impacting non-carcinogenic and carcinogenic risks; and As, Cr, and Cu are the dominant elements impacting potential ecological risks. These mainly originate from geological sources, coal gangue sources, mine drainage sources and agricultural sewage discharge sources. The study showed the sources of groundwater pollution in multiple aquifers and their priority treatment areas, providing a basis for groundwater management and protection.


Assuntos
Água Subterrânea , Metaloides , Oligoelementos , Poluentes Químicos da Água , Oligoelementos/análise , Manganês , Águas Residuárias , Monitoramento Ambiental/métodos , Minerais , Carbonato de Cálcio , Carvão Mineral/análise , China , Poluentes Químicos da Água/análise
17.
Environ Monit Assess ; 194(12): 899, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36269437

RESUMO

Total hardness (TH) is an important index representing the water suitability for domestic purpose. TH is represented mainly by Ca2+ and Mg2+ which are essential elements for human bone development. Between 2000 and 2015, the TH values of groundwater in major cities of the Guanzhong Plain varied significantly. The study was carried out to investigate TH variation over 16 years and to examine how effective the grey Markov model was in predicting TH concentrations in time series datasets. The hydrochemical parameters determining TH concentration and their origins were investigated using statistical analysis and geochemical models. The grey Markov model, which is effective in short time series prediction, was used to forecast the multi-time series of TH. The findings demonstrated a prevalence of HCO3- and SO42- in the groundwater types combined with calcite precipitation, gypsum, and dolomite dissolution that increased the concentration of Ca2+, Mg2+, and HCO3-, influencing TH variation. The predicted TH values of the eight monitoring wells for the year 2016 were 1213.66, 124.30, 203.66, 103.01, 349.56, 251.23, 453.31, and 471.81 mg/L, respectively. Datasets with low TH variation were more accurately predicted than datasets with high TH variation. This was especially observed on sample B557 where TH concentration in 2010 was 400.33 mg/L and suddenly dropped to 90.1, 82.6, 85.1, 87.6, and 75.1 mg/L in 2011, 2012, 2013, 2014, and 2015, respectively. The study also shows that the Markov chain model can optimize the GM(1,1) model and improve the prediction accuracy significantly. All samples in Weinan City and one sample in Xi'an City showed a significant decrease in TH concentration. Except one sample in Xi'an City, TH concentrations tended to rise in the other cities (Baoji, Xianyang) of the Guanzhong Plain. This study verified the reliability of the grey Markov model in terms of forecasting time series datasets with high variability, and the results can be referential to similar studies in the world.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Humanos , Monitoramento Ambiental/métodos , Dureza , Fatores de Tempo , Sulfato de Cálcio/análise , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Água Subterrânea/análise , China , Carbonato de Cálcio/análise , Água/análise
18.
Artigo em Inglês | MEDLINE | ID: mdl-36142024

RESUMO

The work aimed to show the applicability of geological studies to the investigation of radiation risk assessment due to the presence of naturally occurring radionuclides of terrestrial origin in the soil. Soil samples were taken from a Tatra Mountains area for which geological maps were available. The concentration of selected radionuclides incl. 40K, 238U and 232Th was determined by gamma-ray spectrometry with a HPGe-detector. Radioactivities and calculated absorbed dose rates were co-related to complex bedrock matrices based on an original methodology. The correlations were proved by performing a Principal Component Analysis (PCA). The rocks that had a significant impact on the rate of absorbed dose from the soil were strongly related to the radioactivity of the uranium series. The share of the following fractions was the most significant: granite with pegmatite, gneiss, granitoid and gneiss, coquina, marl and glauconite, hard limestone, dolomite and limestone. The rock types additionally showed good correlation with radioisotopes from the thorium series. Granitoids with potassium feldspar, on the other hand, contributed the largest share of 40K radioisotope content.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Urânio , Radiação de Fundo , Carbonato de Cálcio , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Medição de Risco , Solo , Poluentes Radioativos do Solo/análise , Tório/análise , Urânio/análise
19.
Drug Alcohol Depend ; 240: 109640, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36179506

RESUMO

Delta-8-tetrahydrocannabinol (Δ8-THC) is a psychotropic cannabinoid produced in low quantities in the cannabis plant. Refinements in production techniques, paired with the availability of inexpensive cannabidiol substrate, have resulted in Δ8-THC being widely marketed as a quasi-legal, purportedly milder alternative to Δ9-THC. Yet, little research has probed the behavioral and physiological effects of repeated Δ8-THC use. The present study aimed to evaluate the effects of acute and repeated exposure to Δ8-THC. We hypothesized that Δ8-THC produces effects similar to Δ9-THC, including signs of drug tolerance and dependence. Adult male and female C57BL/6J mice were treated acutely with Δ8-THC (6.25-100 mg/kg, i.p.) or vehicle and tested in the tetrad battery to quantify cannabimimetic effects (i.e., catalepsy, antinociception, hypothermia, immobility) as compared with a non-selective synthetic cannabinoid (WIN 55,212-2) and Δ9-THC. As previously reported, Δ8-THC (≥12.5 mg/kg) induced cannabimimetic effects. Pretreatment with the CB1 receptor-selective antagonist rimonabant (3 mg/kg, i.p.) blocked each of these effects. In addition, repeated administration of Δ8-THC (50 mg/kg, s.c.) produced tolerance, as well as cross-tolerance to WIN 55,212-2 (10 mg/kg, s.c.) in tetrad, consistent with downregulated CB1 receptor function. Behavioral signs of physical dependence in the somatic signs, tail suspension, and marble burying assays were also observed following rimonabant-precipitated withdrawal from Δ8-THC (≥10 mg/kg BID for 6 days). Lastly, Δ8-THC produced Δ9-THC-like discriminative stimulus effects in both male and female mice. Together, these findings demonstrate that Δ8-THC produces qualitatively similar effects to Δ9-THC, including risk of drug dependence and abuse liability.


Assuntos
Canabidiol , Canabinoides , Animais , Camundongos , Dronabinol/farmacologia , Rimonabanto , Piperidinas/farmacologia , Camundongos Endogâmicos C57BL , Pirazóis/farmacologia , Carbonato de Cálcio , Receptor CB1 de Canabinoide
20.
Braz J Biol ; 84: e264473, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36169410

RESUMO

The present study was carried out in Hayat Abad Industrial Estate located in Peshawar to assess the levels of cadmium (Cd) that were present in the soil as well as the plant parts (Roots and shoots). To evaluate the phytoremediation potential of the plants different factors i.e. Bioconcentration Factor (BCF), Translocation Factor (TF), and Bioaccumulation Coefficient were determined. These plants were grown in their native habitats (BAC). We have analysed, cadmium concentration from soil which are collected from 50 different locations ranged from 11.54 mg/Kg (the lowest) to 89.80 mg/Kg (highest). The maximum concentration (89.80 mg/Kg) of cadmium was found in HIE-ST-16L Marble City and HIE-ST-7 Bryon Pharma (88.51 mg/Kg) while its minimum concentration (12.47 mg/Kg) were detected in the soil of Site (HIE-ST-14L Royal PVC Pipe) and (11.54 mg/Kg) at the site (HIE-ST-11 Aries Pharma). Most plant species showed huge potential for plant based approaches like phyto-extraction and phytoremediation. They also showed the potential for phyto-stabilization as well. Based on the concentration of cadmium the most efficient plants for phytoextraction were Cnicus benedictus, Parthenium hysterophorus, Verbesina encelioides, Conyza canadensis, Xanthium strumarium, Chenopodium album, Amaranthus viridis, Chenopodiastrum murale, Prosopis juliflora, Convolvulus arvensis, Stellaria media, Arenaria serpyllifolia, Cerastium dichotomum, Chrozophora tinctoria, Mirabilis jalapa, Medicago polymorpha, Lathyrus aphaca, Dalbergia sissoo, Melilotus indicus and Anagallis arvensis. The cadmium heavy metals in the examined soil were effectively removed by these plant species. Cerastium dichotomum, and Chenopodium murale were reported to be effective in phyto-stabilizing Cd based on concentrations of selected metals in roots and BCFs, TFs, and BACs values.


Assuntos
Metais Pesados , Mirabilis , Poluentes do Solo , Biodegradação Ambiental , Cádmio , Carbonato de Cálcio , Metais Pesados/análise , Raízes de Plantas/química , Plantas , Cloreto de Polivinila , Solo , Poluentes do Solo/análise
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