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1.
Environ Sci Pollut Res Int ; 31(17): 24768-24787, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38523214

RESUMO

An alternative method to conventional synthesis is examined in this review by the use of plant extracts as reducing and capping agents. The use of plant extracts represents an economically viable and environmentally friendly alternative to conventional synthesis. In contrast to previous reviews, this review focuses on the synthesis of nano-compounds utilizing plant extracts, which lack comprehensive reports. In order to synthesize diverse nanostructures, researchers have discovered a sustainable and cost-effective method of harnessing functional groups in plant extracts. Each plant extract is discussed in detail, along with its potential applications, demonstrating the remarkable morphological diversity achieved by using these green synthesis approaches. A reduction and capping agent made from plant extracts is aligned with the principles of green chemistry and offers economic advantages as well as paving the way for industrial applications. In this review, it is discussed the significance of using plant extracts to synthesize nano-compounds, emphasizing their potential to shape the future of nanomaterials in a sustainable and ecologically friendly manner.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Nanopartículas Metálicas/química , Extratos Vegetais/química , Química Verde , Nanoestruturas/química , Plantas/química , Antibacterianos
2.
Sci Rep ; 14(1): 5743, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459117

RESUMO

There is an increasing concern about the health effects of exposure to a mixture of pollutants. This study aimed to evaluate the associations between serum levels of heavy/essential metals ([Arsenic (As), Cadmium (Cd), Mercury (Hg), Lead (Pb), Nickel (Ni), Chromium (Cr), Copper (Cu), Iron (Fe), and Zinc (Zn)]) and the risk of developing cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2D). Data were collected from 450 participants (150 with CVDs, 150 with T2D, and 150 healthy subjects) randomly selected from the Ravansar Non-Communicable Disease (RaNCD) cohort in Western Iran, covering the years 2018-2023. Trace element levels in the serum samples were assayed using ICP-MS. Logistic regression was performed to estimate the adjusted risk of exposure to single and multi-metals and CVD/T2D. Odds ratios were adjusted for age, sex, education, residential areas, hypertension, and BMI. The mixture effect of exposure to multi-metals and CVD/T2D was obtained using Quantile G-computation (QGC). In the logistic regression model, chromium, nickel, and zinc levels were associated with CVD, and significant trends were observed for these chemical quartiles (P < 0.001). Arsenic, chromium, and copper levels were also associated with T2D. The weight quartile sum (WQS) index was significantly associated with both CVD (OR 4.17, 95% CI 2.16-7.69) and T2D (OR 11.96, 95% CI 5.65-18.26). Cd, Pb, and Ni were the most heavily weighed chemicals in these models.The Cd had the highest weight among the metals in the CVD model (weighted at 0.78), followed by Hg weighted at 0.197. For T2D, the serum Pb (weighted at 0.32), Ni (weighted at 0.19), Cr (weighted at 0.17), and Cd (weighted at 0.14) were the most weighted in the G-computation model. The results showed the significant role of toxic and essential elements in CVDs and T2D risk. This association may be driven primarily by cadmium and mercury for CVDs and Pb, Ni, Cr, and Cd for T2D, respectively. Prospective studies with higher sample sizes are necessary to confirm or refute our preliminary results as well as to determine other important elements.


Assuntos
Arsênio , Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Mercúrio , Metais Pesados , Oligoelementos , Adulto , Humanos , Oligoelementos/análise , Cádmio/análise , Cobre/análise , Arsênio/análise , Níquel/análise , Diabetes Mellitus Tipo 2/epidemiologia , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Chumbo , Estudos Prospectivos , Metais Pesados/análise , Zinco , Mercúrio/análise , Cromo
3.
Environ Sci Pollut Res Int ; 31(14): 21370-21379, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38388980

RESUMO

In this article, we present the synthesis of binary CdAl4O7/CdO nanocomposites using green tea extracts and green chemistry methods for high-performance hydrogen storage. The green tea extract contains bioactive compounds (polyphenols) that act as reducing agents, which facilitate the reaction between metal ions and water. By examining the structural and morphological characteristics of the obtained substrates using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR), it was demonstrated that the nanocomposites were successfully synthesized. We evaluated the electrochemical performance of the synthesized CdAl4O7/CdO nanocomposites using a three-electrode chronopotentiometry system. According to the results, the synthesized nanocomposites are capable of storing 1750 mAh/g of hydrogen at a constant current of 1 Amp. By using green tea extract as a natural structure-directing agent, the CdAl4O7/CdO nanocomposite can be developed more sustainably as high-performance hydrogen storage materials. Ultimately, this work contributes to the advancement of sustainable energy storage through the synthesis of a promising new material.


Assuntos
Hidrogênio , Nanocompostos , Espectroscopia de Infravermelho com Transformada de Fourier , Nanocompostos/química , Difração de Raios X , Chá/química
4.
Environ Sci Pollut Res Int ; 31(2): 2555-2568, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38066264

RESUMO

The WO3-Fe3O4/reduced graphene oxide (rGO) composite was synthesized with a hydrothermal method for the photocatalytic removal of diazinon (DZ) in visible light. The influence of catalyst concentration (0.5-1.5 g L-1), pH (5-9), and initial pollutant value (5-15 mg L-1) on the pesticide degradation was studied. The performance of the WO3-Fe3O4/rGO nanocomposite for DZ degradation under visible light shows 94% degradation of 5 mg L-1 DZ for 100 min with 1 g L-1 nanocomposite, and the degradation kinetic was modeled in pseudo-first order (PFO) and the maximum kobs was 0.0248 min-1. The photocatalytic mechanism and the intermediates of DZ degradation were identified. In addition, the WO3-Fe3O4/rGO catalyst showed reusability after 4 runs. The results of this work illustrate that the WO3-Fe3O4/rGO nanocomposite can be applied for real use owing to its high catalytic performance.


Assuntos
Grafite , Praguicidas , Compostos Organofosforados , Luz , Diazinon , Catálise
5.
Sci Rep ; 13(1): 20718, 2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-38007565

RESUMO

Microplastics (MPs) as an emerging pollutant can affect aquatic organisms through physical ingestion, chemical problems and possible creation of biological layers on their surfaces in the environment. One of the significant ways for MPs to enter the aquatic environment is through the effluent discharge of wastewater treatment plants (WWTPs). In this study, first, the concentration and characteristics of MPs in secondary wastewater effluent, and the influential variables related to the coagulation process, for MPs removal were identified using systematic reviews of previous studies. Then, the most proper MPs characterization and coagulation variables were chosen by experts' opinions using a fuzzy Delphi method. Therefore, the experiment tested in conditions close to the full-scale wastewater treatments. Finally, in the laboratory removal of MPs by coagulation of polyamide (PA), polystyrene (PS), and polyethylene (PE), < 125 and 300-600 µm in size, was tested by a jar test applying Al2(SO4)3 in doses of 5 to 100 mg/L plus 15 mg/L polyacrylamide as a coagulant aid. Using R and Excel software, the results were analyzed statistically. It was concluded that the maximum and minimum removal efficiency was 74.7 and 1.39% for small PA and large PE, respectively. Smaller MPs were found to have higher removal efficiency. The MPs type PA achieved greater removal efficiency than PS, while PE had the least removal efficiency.

6.
Int J Environ Health Res ; : 1-16, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37496422

RESUMO

In the current study to investigate the characte - rization of Microplastic - released into the Qara-Sou river, Kermanshah, Iran, 12 sampling sites were surveyed along a 100 km stretch of the river. The maximum and minimum numbers of MPs were about 10,000 and 45,000 items per m3. The average concentration of MPs in the Qara-sou river was 23,666 ± 12147 items per m3. The dominant size and shape of MPs ranged from 0.025 to 1 mm (~44%) and fiber shapes (~78%). In addition, SEM-EDS analyses confirmed the presence of carbon-dominant peaks with O, Ca, Fe, Al, and Si. FTIR spectra have identified some MPs in the PVC, PU, PS, PE, and nylon polymer categories. A high level of MPs was discharged into the Qara-sou river, which should be attracting the attention of the community and decision-makers to reduce damage to the environment and human health.

7.
Environ Monit Assess ; 195(7): 857, 2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37330424

RESUMO

The threat of microplastics (MPs) in aquatic systems is almost a new challenge in environmental management. The municipal wastewater treatment plants (WWTPs) act both as collectors of MPs from anthropic use and as a source to natural environments. This study is aimed to determine the abundance, characteristics, and removal of MPs in a municipal WWTP with conventional activated sludge process. Particle size/type, influent loads, and removal rate of MPs in bar screen, grit chamber, primary sedimentation, returned activated sludge, and secondary clarification units of this WWTP were studied by collecting composite samples from wastewater and sludge over a 3-month sampling campaign. Suspected MP particles were counted by light microscopy and characterized using SEM, EDS, FTIR, and TGA-DSC techniques. The mean total MPs, fibers, and fragment concentration after the grit chamber were 6608, 3594, and 3014 which were reduced to 1855, 802, and 1053 particles/L in the effluent, respectively. The sludge retention of total MPs, fibers, and fragments were 8001, 3277, and 4719 particles/L, respectively. The overall efficiency of WWTP with an activated sludge process to remove MPs was 64% and it removed 66.6% and 60% of fibers and fragments, respectively. Fibers were the dominant shape for the collected samples after the grit chamber and fragments were prevalent in the effluent. Polyethylene polymer was detected in most wastewater samples. Existing treatment processes are effective in the removal of MP particles but still act as a potential source to the aquatic ecosystem.


Assuntos
Microplásticos , Poluentes Químicos da Água , Águas Residuárias , Plásticos , Esgotos , Eliminação de Resíduos Líquidos/métodos , Irã (Geográfico) , Ecossistema , Poluentes Químicos da Água/análise , Monitoramento Ambiental
8.
Heliyon ; 9(5): e15664, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37187907

RESUMO

The present study was carried out in the two phases of systematic review and experimental research. First, for the systematic review phase, Web of Science, Scopus, and PubMed as electronic databases were utilized to find research articles distributed up to March 5, 2021, related to the removal of microplastics by coagulation. In total, 104 publications were found, of which 14 were reviewed for deriving the variables and research design. Then, in the experimental phase, the experiment was carried out based on the variables derived from the systematic phase for three microplastic types (polyethylene, polystyrene, and polyamide) and five coagulants (polyaluminum chloride (PAC), ferric chloride (FeCl3), aluminum chloride (AlCl3), alum (Al(OH)3) and aluminum sulfate (Al2(SO4)3)) in bench scale study. The differences between removal efficiencies in terms of type, shape, concentration, and size of microplastics within the looked into article was analyzed utilizing ANOVA or Kruskal-Wallis test (for parametric or nonparametric analysis, respectively). The results of experimental phase show that the removal efficiency of different microplastics was significantly different, and it was equal to 65, 22, and 12% on average for PA, PS, and PE, respectively. These averages are much lower than the average removal efficiency calculated in the reviewed articles (78 and 52% for PS and PE, respectively). The removal efficiency of microplastics types by coagulants was not significantly different. As a result, a coagulant that has the lowest dose can be selected as the most suitable coagulant, which is Al(OH)3 in this study.

9.
Rev Environ Health ; 38(2): 313-326, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35436046

RESUMO

Amoxicillin (AMX) is one of the antibiotics in the penicillin category that is used in various fields. Considering the harmful effects of its remains, it is necessary to survey the ways to remove this compound. Advanced oxidation process (AOPs), specially photo-Fenton has been used for the removal of AMX. This study has been conducted based on PubMed, Google Scholar, DOAJ, Web of Science, and Scopus databases during the years 2008-2019. Some factors such as the aquatic solution, light source characteristics, iron, and H2O2 concentration, AMX degradation percentage, removal of total organic carbon percentage, and AMX concentration have been surveyed to optimize the process. Studies showed that the photo-Fenton process is highly dependent on pH, and in most studies, the highest efficiency has been observed in acidic pH values. Using a more energy light source can be effective in reducing the use of catalysts and oxidizers. The combined methods of AOPs such as photo-Fenton, electro-Fenton, and photo-electro-Fenton have higher efficiency in increasing mineralization than the photon process. The use of synthetic wastewater has a higher efficiency in the degradation of AMX than in real wastewater in the photo-Fenton process, which can be due to the absence of the interfering agents in synthetic environments.


Assuntos
Amoxicilina , Poluentes Químicos da Água , Amoxicilina/química , Águas Residuárias , Peróxido de Hidrogênio/química , Ferro , Oxirredução , Poluentes Químicos da Água/química
10.
Rev Environ Health ; 38(1): 97-109, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-34973052

RESUMO

Today microplastics (MPs) have received worldwide attention as an emerging environmental pollution which is one of the four major global environmental threat and health hazard to human as well. Unfortunately, MPs have been founded in the all environments and media include air, water resources, sediments, and soil. It should not be forgotten MPs have also been detected in food and processing products like tuna. MPs can be ingested by marine organisms such as zooplankton, fish and birds. Accumulation and distribution of MPs by commercially important aquatic organisms is expected to lead to greater exposure risk for human populations with possible adverse effects over time. The aim of this work was to review the published literature regarding the contamination of commercial fish muscle for human consumption. Furthermore, a short revision of the environmental contamination and human health effects by MPs are included. We also estimated human daily intake considering the worldwide contamination of commercial fish muscle ranged from 0.016 items/g muscle of fish to 6.06 items/g muscle of fish. MPs have been found in 56.5% of the commercial fish samples analysed here. As fish is used in human food table across the word, they constitute a long-term exposure route for all humans and raise the concern about the potential public health risk.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Humanos , Microplásticos/efeitos adversos , Microplásticos/análise , Plásticos/efeitos adversos , Poluição Ambiental/análise , Peixes , Saúde Pública , Monitoramento Ambiental , Poluentes Químicos da Água/análise
11.
Rev Environ Health ; 38(2): 265-279, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35390247

RESUMO

Over the past few decades, phthalate esters (PAEs) used as additives to improve the persistence and flexibility of polymeric materials. They are also used in cosmetics, insect repellents, and propellants, and their continuous input into drinking waters has constituted a serious risk to human health and the environment. DBPs are compounds classified as hazardous substances and have teratogenic properties. Due to the high bioaccumulation of DBP, they have toxic properties in different organisms, making it very important to remove PAEs before discharging them into environments. In this study a systematic review was designed to evaluate Advanced oxidation processes (AOPs) studies which have successfully treated contaminated water with PAEs. Among AOPs, particularly photocatalytic, UV/H2O2 photolysis, sonolysis, and ozone-based processes were more tried to degrade PAEs in aqueous solutions. Additionally, a more detail of each AOPs was explained. Findings showed that all advanced oxidation processes, especially combined AOPs have good results in the degradation of PAEs in water.


Assuntos
Água Potável , Ácidos Ftálicos , Poluentes Químicos da Água , Humanos , Peróxido de Hidrogênio , Poluentes Químicos da Água/análise , Ácidos Ftálicos/análise , Ésteres/análise , China
12.
Rev Environ Health ; 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36351327

RESUMO

Treatment with non-thermal plasma is a reliable technology to oxidize chemical impurities that exist in polluted water, wastewater, and leachate, those degradation-resistant and cannot be removed by conventional treatment methods. In this study, the effective factors affecting in the formation ofreactive oxygen species in non-thermal plasma treatment process, as a new advanced oxidation process method explianed. In this manner, all associated manuscripts existed in the main databases including Google Scholar, Science Direct, PubMed, and Open Access Journal Directory from 1990 until 2022 were explored. The utilized keywords were involved non-thermal plasma, Cold plasma, Measurement, •OH, O3 and UV. Overall, 8,813 articles were gathered and based on the relevance titles and abstracts, 18 paper were selected for further reviewing. In several studies, plasma techniques have been used to treat water, wastewater and leachate, but few studies have evaluated the factors influencing the production of ROS species by non-thermal plasma. The non-thermal plasma destroys pollutants by reactive free radicals spices (hydroxyl, hydrogen atoms, etc.) a combination effect of strong electric fields, energetically charged particles, and ultrasound. Some factors such as water vapor, hydraulic retention time, inter-electrode spacing, discharge power density, and aeration of the effluent as well as use of catalyst have direct effect on the reactive oxygen species formation. If these factors controlled within the best ranges, it will promote the oxidizing radical production and system performance. Also, high-energy electrons and oxidizing species produced in the cold plasma system can well degrade most of pollution in water and wastewater.

14.
J Fluoresc ; 32(5): 1733-1741, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35675001

RESUMO

In this research, DNA-modified carbon dots (CDs) were exploited to construct a fluorescence assay for breast cancer genes (BRCA1, a potential marker for cancer diagnosis) detection. For this purpose, water-soluble synthesized CDs were functionalized with 19 mer-modified oligonucleotides (capture probe). By adding the DNA target, the specific binding between the DNA probe and DNA target causes fluorescence quenching. The assay displayed a fine capability of sensing the BRCA1 gene with a linear range (R2 = 0.9918) of 36 attomolar (aM) to 532 femtomolar (fM) and a detection limit of 2 attomolar. This homogeneous process does not need additional separation and washing steps of un-hybridized DNA. To assess the selectivity, the prepared biosensor responses were evaluated in solutions containing single-base mismatched DNA sequences, three-base mismatched DNA sequences, or non-complementary DNA sequences, separately. To demonstrate the practical application of the designed biosensor, the extracted DNA from blood samples of breast cancer patients was utilized as real samples. When the CDs-DNA bioassay was exploited in the imaging of MCF-7 cancer cells, strong fluorescence emission was observed. After incubation times, both the cells' size and shape remained unchanged. The results validated that the CDs are an extremely great bioimaging candidate in disease diagnosis, biomedicine investigation, and managing cancer diseases.


Assuntos
Neoplasias da Mama , Pontos Quânticos , Proteína BRCA1/genética , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/genética , Carbono , DNA/genética , Feminino , Corantes Fluorescentes , Genes BRCA1 , Humanos , Espectrometria de Fluorescência/métodos
15.
Mar Pollut Bull ; 177: 113462, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35255348

RESUMO

In the present study Web of Science, Scopus, and PubMed as electronic databases were used to find work published up to October 27, 2020 about microplastics evaluation in conventional wastewater treatment plants. In total, 407 publications were found, of which 77 were eligible for meta-analysis. A comprehensive meta-analysis was undertaken to evaluate the relevant publications regarding microplastics abundance. The average microplastics abundance was within the 1-31,400, 0.2-12,580, 0.002-7863, and 0.003-447 items range per liter wastewater for influent, primary, secondary, and tertiary treatment steps, respectively. The difference between the abundance of microplastics characterization for the different treatment steps was analyzed using ANOVA or Kruskal-Wallis test (depending on the data distribution). According to the pooled data, the average microplastics abundance was 124.04, 20.67, 5.62, and 1.97 (items/l) for influent, primary, secondary, and tertiary treatment. The results of Egger's test (t = 7.49, P ≤ 0.0001) were statistically significant, suggesting the existence of publication bias.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Monitoramento Ambiental , Microplásticos , Plásticos , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Poluentes Químicos da Água/análise
16.
Environ Sci Pollut Res Int ; 29(3): 3199-3212, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34731423

RESUMO

Iron deficiency is the most common nutritional disorder detrimental to the behavior, cognitive performance, immune system, and physical growth of infants and preschool- and school-age children. Iron deficiency anemia (IDA) increases children's susceptibility to some metals, including the highly toxic lead (Pb), but the character of this relationship is still disputed. Thus, this study aimed to review and meta-analyze the association between the IDA and blood lead levels (BLL) among children, based on papers indexed by international scientific databases and published up to September 2021. A search was performed of the literature in several databases including the ISI Web of Science, PubMed, and Scopus. The final papers were assessed concerning their quality based on the Newcastle-Ottawa Scale (NOS) for cross-sectional studies. Moreover, analyses were performed using R statistical software with the "meta" package. Of the 1528 articles found, only 12 studies met the inclusion criteria and were considered in the meta-analysis. Significantly higher BLL in IDA children (SMD = 2.40; CI 95%, 0.93-3.87 µg/L; p = 0.0014) was seen when compared to non-IDA children. Moreover, the pooled OR is equal to 2.75 (CI 95%, 1.10-6.85 µg/L; p = 0.0303) suggesting a higher risk of IDA development among children with BLL > 10 µg/dL. Thus, we recommend systematic monitoring of Fe and Pb levels among children, especially in countries with limited sources of nutritious food. Since only a few studies were available for this meta-analysis, further studies are necessary to examine the association between IDA and BLL in detail.


Assuntos
Anemia Ferropriva , Deficiências de Ferro , Criança , Pré-Escolar , Estudos Transversais , Humanos , Lactente , Chumbo
17.
Int J Environ Health Res ; 32(1): 155-167, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32183563

RESUMO

In this study, an integration of multi-criteria evaluation, geographic information system, and remote sensing techniques were used for site selection of medical waste landfills in Kermanshah, Iran. Also, an environmental risk assessment for the selected site has been conducted in order to minimize the possible hazardous. The GIS and remote sensing were used for acquiring and preparing layers and maps and the multi-criteria evaluation was used for setting aim, criteria selection, criteria weighting, and final decision making. The results showed that only 1.2% of the study area is scored high-suitable, while 90% of the area is considered unsuitable that makes this region critical for preservation. After further assessment and field visits, a suitable site was selected for landfilling. Environmental risk assessment showed that the selected site poses a low-level of risks to the environment and surrounding areas and this is because various environmental and health aspects have been considered in the site selection process.


Assuntos
Resíduos de Serviços de Saúde , Eliminação de Resíduos , Técnicas de Apoio para a Decisão , Sistemas de Informação Geográfica , Irã (Geográfico) , Resíduos Sólidos , Instalações de Eliminação de Resíduos
18.
Environ Sci Pollut Res Int ; 29(6): 8232-8241, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34482458

RESUMO

The current study aimed to evaluate the levels of some toxic and essential elements (Pb, Cd, Cu, Ti, Ni, Cr, Co, Fe, Ca, Hg, Mn, Se, and Zn) in the urine of opium-addicted compared to non-addicted cases. In this study, 126 participants were recruited and their fasting urine samples were collected (63 opium-addicted and 63 non-addicted subjects served as the reference group). ICP-MS was utilized to detect the concentration of trace elements. Results exhibited that the concentration of all elements than Ni, Cu, and Zn was markedly different between the addicted and non-addicted groups. Compared to controls, the Cd, Cr, Co, Hg, Mn, Pb, Se, and Ti levels were higher among opium-addicted cases (p < 0.05) whereas the Fe and Ca concentrations were higher among controls (p < 0.05). Robust regression analysis showed no statistically significant effect of gender on element levels. It revealed that age was associated with the levels of Ni and Cu only and also the route of administration was related to the urinary levels of Co, Cr, Hg, and Mn. In conclusion, results confirmed that it is opium consumption that affects the concentration levels of most elements.


Assuntos
Mercúrio , Metais Pesados , Oligoelementos , Humanos , Irã (Geográfico) , Mercúrio/análise , Metais Pesados/análise , Ópio , Oligoelementos/análise
19.
J Environ Health Sci Eng ; 19(2): 1743-1751, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34900303

RESUMO

Nowadays, anaerobic processes are used for leachate treatment and biogas production that can be used as a source of renewable and eco-friendly energy. However, for optimal performance of the anaerobic system for gas production, an appropriate method must be used to reduce the inhibitors in the leachate. In this study an anaerobic baffled reactor (ABR) was used for investigating impact of OLR on biogas production and changes of alkalinity and pH. In order to decline inhibitors concentration on anaerobic microorganisms, zeolite was considered as a media and changes of biogas production was surveyed in different filling ratios. The highest produced biogas at the filling ratios of 10 %, 20 and 30 % were 0.6, 0.63 and 0.9 L/day, respectively and OLR increasing resulted in increase in produced biogas. The values of alkalinity and pH remained in the optimum range for methanogenic bacteria. In all three filling ratios, concentration of ammonia increased with increasing organic loading rate but it has not adverse effect on biogas production. Despite of high concentration of heavy metals, anaerobic baffled reactor with zeolite provided suitable condition for anaerobic microorganisms and biogas production.

20.
J Environ Manage ; 299: 113620, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34481374

RESUMO

In the present study, the occurrence and characterization of microplastics (MPs) content in the fishes of the river was studied. Therefore, six sampling stations were considered for fishing. Then, the entire stomach of fishes was investigated by visual stereomicroscope, FTIR, SEM, and EDX to analyze the content of the samples, by MPs type, shape, color, and size. The most frequency of MPs was observed in Ghazanchi (Siii) and Kermanshah (Siv) stations which were close to urban and industrial areas. Most types of detected MPs included polystyrene, polyethylene, and nylon with the highest frequency observed in Luciobarbus caspius and Alburnus chalcoides fishes. Overall, the frequency of detected MPs in the caught fishes was 93.8%. Indeed, MPs with a size of 0.025-1 mm (25-1000 µm) were the most frequency of MPs in fishes. The frequency of MPs shapes was fiber (85.12%), fragment (12.32%), foam (0.77%), film (1.21%), and microbead (0.56%), respectively. The highest and lowest percentage of MPs belonged to black and green with an abundance of 63% and 2%, respectively. The result implies that lots of riverine fishes are polluted with MPs, those which can move into the food chain.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Sistema Digestório/química , Monitoramento Ambiental , Peixes , Plásticos , Polietileno , Poluentes Químicos da Água/análise
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