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1.
Heliyon ; 10(9): e30853, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38765091

RESUMO

Plastic wastes -including cigarette butts (CBs)- are dangerous for marine ecosystems not only because they contain hazardous chemicals but also because they can finally turn into micro- or even nano-particles that may be ingested by micro- and macro-fauna. Even large pieces of plastics can trap animals. In this research, the pollution status of macroplastics (abundance, size, type, and colour) and cigarette butts (CBs, number/m2) on the northern coasts of the Persian Gulf has been investigated. A total of 19 stations were explored in Bushehr province (Iran), which covers a length equivalent to 160 km of the Persian Gulf coastline. Among the collected plastic waste (2992 items), disposable mugs were the most frequent (18 %). Plastics with sizes 5-15 cm were the most abundant, and the most common type of plastic was PET (P-value <0.05). The origin of most macroplastics was domestic (2269 items). According to the Index of Clean Coasts (ICC), most surveyed beaches were extremely dirty. The average number and density of CBs in this study were 220 and 2.45 items/m2, respectively. Household litter was the most abundant type of waste in the studied beaches, and this problem can be better managed by training and improving the waste disposal culture. In general, it is suggested that an integrated and enhanced management for fishing, sewage and surface water disposal, and sandy recreational beaches be implemented in Bushehr to control plastic waste.

2.
Heliyon ; 10(7): e28189, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38560122

RESUMO

Increasing of tobacco consumption around the world has led to the production of a large volume of waterpipe wastewater that enter the environment (e.g., coastal areas)and threaten aquatic creatures. However, until now, no research has been carried out on the amounts of monocyclic and polycyclic aromatic hydrocarbons (PAHs) in hookah wastewater. In the current study, the levels of PAHs and BTEX compounds in waterpipe wastewater resulting from the use of different tobacco brands were determined and their eco-toxicological effects were also evaluated. The mean levels of Æ©PAHs in waterpipe wastewater of Al Tawareg, Al-Fakher, Nakhla, Tangiers and traditional tobacco brands samples were 3.48 ± 1.65, 3.33 ± 1.52, 3.08 ± 1.25, 2.41 ± 0.87 and 0.70 ± 0.13 µg/L, respectively. The mean levels of Æ©BTEX in waterpipe wastewater of Al Tawareg, Al-Fakher, Nakhla, Tangiers and traditional tobacco brands samples were also 2.53 ± 0.61, 2.65 ± 0.78, 2.51 ± 0.72, 2.35 ± 0.56, and 0.78 ± 0.12 µg/L, respectively. The maximum level of PAHs and BTEX compounds in all brands/flavors samples were for naphthalene (Naph) and toluene, respectively. The concentrations of some PAHs (fluoranthene (Flrt), anthracene (Ant), benzo(b)fluoranthene (BbF), benzo(b)fluoranthene (BkF), benzo (g,h,i)perylene (BghiP) and dibenzo (a, h) anthracene (DahA)) and BTEX compounds (benzene) in the waterpipe wastewater samples were more than recommended guidelines and standards by the international reputable organizations such as World Health Organization (WHO) for water quality. Waterpipe wastewater can be introduced as an important origin for the release of these dangerous contaminants into the environmental matrixes. Therefore, more stringent regulations should be considered for the safe disposal of such hazardous wastes including waterpipe wastewater.

3.
Environ Res ; 256: 118957, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38636645

RESUMO

In the current investigation, MnFe2O4/ZIF-8 nanocomposite was generated as a magnetic nanoadsorber using the extract of Dracocephalum plant and characterized by XRD, FTIR, VSM, BET, FESEM, EDS-mapping, TEM, XPS, TPD-NH3, and TGA analyses. Also, to determine its efficiency in the adsorption process of tetracycline, the effect of pH (3-9), nanocomposite dose (0.025-2 g/L), initial pollutant concentration (5-100 mg/L), contact time (5-200 min), and temperature (5-50 °C) were studied. The results of the morphological properties of the magnetic nanocomposite confirmed the spherical shape of this nanoadsorber with an average size of 54 ± 31 nm. BET analysis showed that modification of MnFe2O4 material with ZIF-8 as a new nanoadsorber leads to excellent modification of SBET (143.8 m2/g) and VTotal (0.44 cm3/g). The highest removal efficiency of tetracycline in optimal conditions (pH = 7, contact time = 120 min, nanocomposite dose = 1.5 g/L, and temperature = 20 °C for a tetracycline concentration of 20 mg/L) was 90.11%. As the temperature increased, the removal efficiency increased from 40.46% to 95.06% during 120 min, which indicates that the adsorption reaction is endothermic. In addition, the data obtained from the isotherms of Langmuir (R2 = 0.958), Freundlich (R2 = 0.534), and Temkin (R2 = 0.747) showed that the tetracycline adsorption is monolayer and on the homogeneous surface of the synthesized magnetic nanoadsorber. The elimination process of tetracycline by nanoadsorber followed the pseudo-second order model (R2 = 0.998). Investigating the effect of interfering ions also confirmed the decrease in the adsorption efficiency. Also, the investigation of the reusability of the synthesized magnetic nanoadsorber in tetracycline adsorption indicates that after eight cycles, the efficiency decreases by %16.51. According to the results, the magnetic nanocomposite synthesized in this work can be a suitable and economical adsorber for the removal of tetracycline from aqueous environments.

4.
Chemosphere ; 356: 141873, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38593958

RESUMO

Phthalic acid esters (PAEs) are byproducts released from various sources, including microplastics, cosmetics, personal care products, pharmaceuticals, waxes, inks, detergents, and insecticides. This review article provides an overview of the literature on PAEs in landfill leachates, exploring their identification, occurrence, characteristics, fate, and transport in landfills across different countries. The study emphasizes the influence of these substances on the environment, especially on water and soil. Various analytical techniques, such as GC-MS, GC-FID, and HPLC, are commonly employed to quantify concentrations of PAEs. Studies show significant variations in levels of PAEs among different countries, with the highest concentration observed in landfill leachates in Brazil, followed by Iran. Among the different types of PAE, the survey highlights DEHP as the most concentrated PAE in the leachate, with a concentration of 89.6 µg/L. The review also discusses the levels of other types of PAEs. The data shows that DBP has the highest concentration at 6.8 mg/kg, while DOP has the lowest concentration (0.04 mg/kg). The concentration of PAEs typically decreases as the depth in the soil profile increases. In older landfills, concentrations of PAE decrease significantly, possibly due to long-term degradation and conversion of PAE into other chemical compounds. Future research should prioritize evaluating the effectiveness of landfill liners and waste management practices in preventing the release of PAE and other pollutants into the environment. It is also possible to focus on developing efficient physical, biological, and chemical methods for removing PAEs from landfill leachates. Additionally, the effectiveness of existing treatment processes in removing PAEs from landfill leachates and the necessity for new treatment processes can be considered.


Assuntos
Monitoramento Ambiental , Ésteres , Ácidos Ftálicos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Ácidos Ftálicos/análise , Ésteres/análise , Poluentes do Solo/análise , Brasil , Solo/química
5.
Environ Res ; 252(Pt 2): 118931, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38615794

RESUMO

In the present work, the biomass of Aspergillus flavus (AF) was modified using magnetic nanoparticles MnFe2O4 and metal-organic framework of ZIF-67, and its ability to remove tetracycline antibiotic (TCH) was investigated. With the help of physicochemical tests, AF biomass modification with ZIF-67 and MnFe2O4 magnetic nanoparticles was confirmed. Based on the BET value, AF-MnFe2O4-ZIF-67 (139.83 m2/g) has a higher surface value than AF (0.786 m2/g) and AF/MnFe2O4 (17.504 m2/g). Also, the magnetic saturation value revealed that the modified biomass can be isolated from the treated solution using a simple magnetic field. Maximum TCH elimination (99.04%) using AF-MnFe2O4-ZIF-67 was obtained at pH 7, adsorber mass of 1 g/L, adsorption time of 40 min, and TCH content of 10 mg/L. The thermodynamic study indicated that the TCH abatement using the desired composite is spontaneous and exothermic. The experimental results showed that the adsorption process is compatible with the pseudo-second-order kinetic and Freundlich model. The maximum adsorption capacity for AF, AF-MnFe2O4, and AF-MnFe2O4-ZIF-67 was quantified to be 9.75 mg/g, 25.59 mg/g, and 43.87 mg/g, respectively. The reusability of the desired adsorbers was examined in up to 8 steps. The outcomes showed that the adsorbers can be used several times in TCH elimination. The provided composite can remove TCH from hospital wastewater, so it can be suggested for use in water and wastewater treatment works.


Assuntos
Aspergillus flavus , Biomassa , Tetraciclina , Poluentes Químicos da Água , Aspergillus flavus/metabolismo , Tetraciclina/química , Poluentes Químicos da Água/química , Adsorção , Antibacterianos/química , Estruturas Metalorgânicas/química , Compostos Férricos/química , Compostos de Manganês/química , Cinética , Nanopartículas de Magnetita/química , Purificação da Água/métodos , Imidazóis , Zeolitas
7.
Chemosphere ; 356: 141770, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554866

RESUMO

The objective of the present study was to employ a green synthesis method to produce a sustainable ZnFe12O19/BiOI nanocomposite and evaluate its efficacy in the photocatalytic degradation of metronidazole (MNZ) from aqueous media. An artificial neural network (ANN) model was developed to predict the performance of the photocatalytic degradation process using experimental data. More importantly, sensitivity analysis was conducted to explore the relationship between MNZ degradation and various experimental parameters. The elimination of MNZ was assessed under different operational parameters, including pH, contaminant concentration, nanocomposite dosage, and retention time. The outcomes exhibited high a desirability performance of the ANN model with a coefficient correlation (R2) of 0.99. Under optimized circumstances, the MNZ elimination efficiency, as well as the reduction in chemical oxygen demand (COD) and total organic carbon (TOC), reached 92.71%, 70.23%, and 55.08%, respectively. The catalyst showed the ability to be regenerated 8 times with only a slight decrease in its photocatalytic activity. Furthermore, the experimental data obtained demonstrated a good agreement with the predictions of the ANN model. As a result, this study fabricated the ZnFe12O19/BiOI nanocomposite, which gave potential implication value in the effective decontamination of pharmaceutical compounds.


Assuntos
Bismuto , Metronidazol , Nanocompostos , Redes Neurais de Computação , Poluentes Químicos da Água , Zinco , Nanocompostos/química , Bismuto/química , Catálise , Metronidazol/química , Poluentes Químicos da Água/química , Zinco/química , Fotólise , Compostos Férricos/química
8.
Environ Res ; 251(Pt 1): 118641, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38458588

RESUMO

The use of biomass and waste to produce adsorbent reduces the cost of water treatment. The bio-char of Sargassum oligocystum (BCSO) was modified with MnFe2O4 magnetic particles and La-metal organic framework (MOF) to generate an efficient adsorbent (BCSO/MnFe2O4@La-MOF) for fluoride ions (F-) removal from aqueous solutions. The performance of BCSO/MnFe2O4@La-MOF was compared with BCSO/MnFe2O4 and BCSO. The characteristics of the adsorbents were investigated using various techniques, which revealed that the magnetic composites were well-synthesized and exhibited superparamagnetic properties. The maximum adsorption efficiencies (BCSO: 97.84%, BCSO/MnFe2O4: 97.85%, and BCSO/MnFe2O4@La-MOF: 99.36%) were achieved under specific conditions of pH 4, F- concentration of 10 mg/L, and adsorbent dosage of 3, 1.5, and 1 g/L for BCSO, BCSO/MnFe2O4, and BCSO/MnFe2O4@La-MOF, respectively. The results demonstrated that the experimental data adheres to a pseudo-second-order kinetic model. The enthalpy, entropy, and Gibbs free energy were determined to be negative; thus, the F- adsorption was exothermic and spontaneous in the range of 25-50 °C. The equilibrium data of the process exhibited conformity with the Langmuir model. The maximum adsorption capacities of F- ions were determined as 10.267 mg/g for BCSO, 14.903 mg/g for the BCSO/MnFe2O4, and 31.948 mg/g for BCSO/MnFe2O4@La-MOF. The KF and AT values for the F- adsorption were obtained at 21.03 mg/g (L/mg)1/n and 100 × 10+9 L/g, indicating the pronounced affinity of the BCSO/MnFe2O4@La-MOF towards F- than other samples. The significant potential of the BCSO/MnFe2O4@La-MOF magnetic composite for F- removal from industrial wastewater, makes it suitable for repeated utilization in the adsorption process.


Assuntos
Compostos Férricos , Fluoretos , Lantânio , Compostos de Manganês , Sargassum , Poluentes Químicos da Água , Fluoretos/química , Fluoretos/isolamento & purificação , Compostos Férricos/química , Adsorção , Compostos de Manganês/química , Lantânio/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Sargassum/química , Estruturas Metalorgânicas/química , Purificação da Água/métodos , Cinética
9.
Environ Sci Pollut Res Int ; 31(14): 22145-22157, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38403824

RESUMO

Plastic contamination is widely recognized as a major environmental concern due to the entry of small plastic particles into the food chain, thereby posing potential hazards to human health. However, the current understanding of microplastic (MP; < 5 mm) particles in livestock, which serve as an important food source, is limited. This study aims to investigate the concentration and characteristics of MPs in edible tissues of cow and sheep, namely liver, meat, and tripe, obtained from butcher shops in five areas of Bushehr port, Iran. The mean concentration of MPs in different tissues of cow and sheep were 0.14 and 0.13 items/g, respectively. Among the examined tissues, cow meat exhibited the highest concentration of MPs, with a concentration of 0.19 items/g. Nylon and fiber were identified as the predominant polymer types and shapes of MPs found in cow and sheep tissues, respectively. Furthermore, no statistically significant difference was observed in MP concentration across different tissues of cow and sheep. Significantly, this study highlights the elevated hazards associated with exposure to MPs through the consumption of edible cow and sheep tissues, particularly for children who consume meat. The results underscore the potential transfer of MPs from the environment to livestock bodies through their food, contamination during meat processing, and subsequent health hazards for consumers.


Assuntos
Microplásticos , Plásticos , Criança , Animais , Bovinos , Ovinos , Humanos , Gado , Carne , Fígado
10.
Environ Res ; 248: 118234, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38272296

RESUMO

This investigation aimed to scrutinize the level of phthalate esters (PEs) in the landfill leachate of a coastal city in the north of the Persian Gulf and the sensitive ecosystem (soil and water) around it. Soil (two depths) and water samples were prepared from 5 stations in wet and dry seasons. The studied landfill leachate contained 114-303 µg/L of phthalates. The highest concentration of phthalates was related to bis (2-ethylhexyl) phthalate (3257 ng/g) in the wet season at surface soil (0-5 cm) in the landfill site, while the lowest one (6 ng/g) belonged to dimethyl phthalate at sub-surface soil at 700 m from the landfill in the dry season. A significant change in the level of Σ6PEs in the dry (303 µg/L) and wet (114 µg/L) seasons (P ≤ 0.05) was observed for water samples. The PE concentrations in wet times were higher in all soil depths than in dry times. With increasing depth, the content of phthalates decreased in all studied environments. A direct relationship was observed between the phthalates concentration and the pH value of leachate/water and soil. The PEs concentration was linked to electrical conductivity (leachate: R2 = 0.65, P < 0.01 and surface soil: R2 = 0.77, P < 0.05) and the soil organic content. The ecological risk of di-n-butyl phthalate, benzyl butyl phthalate, bis (2-ethylhexyl) phthalate, and di-n-octyl phthalate in the wet season was greater than one. The results showed that significant levels of phthalate esters are released from landfills to the surrounding environment, which requires adequate measures to maintain the health of the ecosystem and nearby residents.


Assuntos
Ácidos Ftálicos , Poluentes Químicos da Água , Água , Poluentes Químicos da Água/análise , Ésteres , Solo/química , Irã (Geográfico) , Ecossistema , Ácidos Ftálicos/química , Instalações de Eliminação de Resíduos
11.
Mar Pollut Bull ; 198: 115825, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38029669

RESUMO

Transport of ballast water is considered a significant vector for dispersion of different pollutants, including microplastics (MPs), throughout the world's oceans. However, there is limited information on MPs in ballast water. Size distribution, polymer type, and ecological risks of MPs in ballast water were investigated for the first time in this study. The mean levels of MPs in ballast water and seawater samples were 12.53 and 11.80 items/L, respectively. MPs with a size category of 50-300 µm was the most abundant. Fiber, black, and polycarbonate (PC) were the predominant shape, color, and polymer type of identified MPs in ballast water and seawater, respectively. The pollution load index (PLI), hazard index (HI), and risk quotient (RQ) indicated high levels of MP pollution, potentially indicating an ecological risk. These findings increase our understanding of the major sources (such as ballast water), transportation routes, and related ecological risks of MPs to marine ecosystems.


Assuntos
Microplásticos , Poluentes Químicos da Água , Microplásticos/análise , Plásticos/análise , Água/análise , Ecossistema , Oceano Índico , Navios , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Polímeros/análise , Medição de Risco
12.
Heliyon ; 9(12): e23129, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38144273

RESUMO

In this research, a total of 51 road dust samples were collected from three districts (Asaluyeh, Bushehr, and Goshoui) in the south of Iran from April to June 2022 and analyzed for the concentration of 7 phthalic acid esters (PAEs) compounds. Asaluyeh was considered as an industrial area (near gas and petrochemical industries), Bushehr as an urban area, and Goshoui as a rural area (far from pollution sources). The PAEs concentration of the street dust samples was determined using a mass detection gas chromatography (GC/MS). The mean ± SD levels of Æ©PAEs in samples from industrial, urban, and rural sources were 56.9 ± 11.5, 18.3 ± 9.64, and 5.68 ± 1.85 µg/g, respectively. The mean concentration levels of Æ©PAEs was significantly (P < 0.05) higher in samples from the industrial area than urban and rural areas. The mean levels of di(2-Ethylhexyl) phthalate (DEHP) in industrial, urban, and rural areas were 20.3 ± 8.76, 4.59 ± 1.71, and 2.35 ± 0.98 µg/g, respectively. The results of the PCA analysis indicate that the likely major sources of PAEs in the road dust in the studied areas are the application of various plasticizers in industry, solvents, chemical fertilizers, waste disposal, wastewater (e.g., agricultural, domestic, and industrial), and the use of plastic films and plastic-based irrigation pipes in greenhouses. As well as, it was found that the non-cancer risk of exposure to dust-bound PAEs was higher for children than for adults. These values were <1 for both age groups (children and adults) and the exposure of inhabitants to PAEs in road dust did not pose a notable non-cancer risk. The cancer risk from exposure to DEHP in road dust was below the standard range of 10-6 in all three areas. Further studies that consider different routes of exposure to these contaminants are needed for an accurate risk assessment. Moreover, since higher PAEs level was found in industrial area, decision-makers should adopt strict strategies to control the discharging of pollution from industries to the environment and human societies.

13.
J Environ Health Sci Eng ; 21(2): 455-462, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37869597

RESUMO

Purpose: Anaerobic-anoxic-aerobic process is one of the biological removal processes of nutrients in wastewater treatment. Phosphorus removal by biological method is a new and developed technique that is done by changing the design of suspended growth systems. Methods: This is a cross-sectional descriptive study, which is a pilot workshop based in the first module, and chemistry, physics and microbiological tests were carried out at the wastewater treatment plant laboratory in one of the cities (Pardis) of Tehran province in 2020-2021 during a period of 12 months. Was completed. In this research, a total of 500 samples were taken from raw wastewater, aeration pond, effluent, secondary sedimentation and return activated sludge. Results: In this research, the internal decay coefficient and the growth efficiency coefficient are equal to d-1 0.1264 and 0.6579 gVSS/gCOD, respectively. And the maximum specific rate of consumption of food substance and the semi-saturation constant of food substance respectively were gCOD/gVSS.d 3.3467 gCOD/m 25.305. If the specific rate of consumption of food substance or efficiency factor in our research is 0.27 gCOD/gVSS.d and the semi-constant Ks saturation equal to 27.9 gCOD/m has been obtained, this actually shows that the organic matter (COD) in the waste water of Pardis city had a higher degradability (sbCOD). Conclusion: According to the obtained results, the synthetic coefficients in the Lineweaver-Burk and Hanes models are suitable, but in the Hofstee model, the amount of K and Kd is less than the optimal amount for the proper exploitation of the pilot.

14.
Heliyon ; 9(3): e14356, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36950564

RESUMO

Tetracycline (TTC) is an antibiotic commonly prescribed to treat bacterial infections in animals and humans because of its low toxicity and antibacterial activity. This study focuses on the removal of TTC from an aqueous media using an activated carbon of Chlorella vulgaris modified with Fe3O4 magnetic composite (ACCV/Fe3O4 mc). The isothermal and kinetic models were studied to understand the adsorption mechanism. The Box-Behnken model was used for experimental design, and the main research parameters were ACCV/Fe3O4 mc mass (0.2-0.8 g/L), reaction time (10-60 min), TTC concentration (5-30 mg/L), and pH (3-11). The highest TTC removal rate of 90.47% was obtained at a pH of 7, a time of 60 min, an ACCV/Fe3O4 mc mass of 0.5 g/L, and an antibiotic concentration of 5 mg/L. TTC removal was fitted with the pseudo-second-order and the Langmuir model. The Langmuir adsorption capacity of TTC was computed to be 26.18 mg/g. The results show that the ACCV/Fe3O4 mc adsorbent significantly removes TTC from the aqueous solution.

15.
Heliyon ; 9(3): e14488, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36925530

RESUMO

In this study, the performance of Ni-FSM-16 and TiO2-FSM-16 photocatalysts in phenol red removal was explored. The XRD, FE-SEM, and BET tests were used to characterize the catalysts. All experiments were performed at ambient temperature and under UV (20 W). The parameters including dye concentration (20-80 mg/L), photocatalyst concentration (0-8 g/L), UV exposure duration, and contact time (0-160 min) were optimized using RSM software. BET values of Ni-FSM-16 and TiO2-FSM-16 were 718.63 m2/g and 844.93 m2/g, respectively. TiO2-FSM-16 showed better performance in dye removal than Ni-FSM-16. At pH 3, the maximum dye removal by TiO2-FSM-16/UV and Ni-FSM-16/UV was obtained 87% and 64%, respectively. The positive hole species had the main role in photocatalytic phenol red removal. The reusability study was done for up to 7 cycles, but the catalysts can be reused effectively for up to 3 cycles. The synergistic factor for the TiO2-FSM-16 and TiO2-FSM-16/UV processes were calculated to be 1.55 and 2.12, respectively. The dye removal efficiency by TiO2-carbon and Ni-carbon was slightly lower than those obtained by the FSM-16 ones. The TiO2-FSM-16 and Ni-FSM-16 catalysts had a suitable surface and acceptable efficiency in phenol red removal.

16.
Mar Pollut Bull ; 187: 114563, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36623469

RESUMO

Most studies on microplastics (MPs) and organisms, regardless of the MPs type and their presence in the environment and organisms, have been performed on a laboratory scale. In this review, reports of simultaneous analysis of the abundance of MPs and organic/inorganic contaminants in aquatic organisms in the natural environment have been collected and bibliometric analysis was performed. Biological and environmental factors affecting MPs absorption by organisms were discussed. The majority of microplastics were identified as fibrous and black with a small size (<500 µm). A positive correlation was reported between microplastic numbers and organic/inorganic contaminants in the tissue of some species. The most positive linear relationship between heavy metal and MPs was reported for Heniochus acuminatus from the Gulf of Mannar. To preserve biodiversity and the risks of transferring MPs and contaminants to aquatic organisms and humans, it is necessary to control microplastic contamination.


Assuntos
Microplásticos , Poluentes Químicos da Água , Humanos , Plásticos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Ecossistema , Organismos Aquáticos
17.
Environ Sci Pollut Res Int ; 30(11): 29566-29580, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36417060

RESUMO

In this study, Alginate@ Fe3O4/Bentonite nanocomposite was utilized to eliminate formaldehyde from wastewater. Structural features of bentonite, bentonite@Fe3O4, and Alginate@Fe3O4@Bentonite were determined using FT-IR, PXRD, Mapping, EDX, TEM, SEM, VSM, and BET analyses. The central composite design method was employed to find the optimal conditions for formaldehyde removal using Alg@Fe3O4@Bent nanocomposite. The maximum formaldehyde uptake efficiency (94.56%) was obtained at formaldehyde concentration of 10.69 ppm, the nanocomposite dose of 1.28 g/L, and pH of 9.96 after 16.53 min. Also, Alginate@Fe3O4@Bentonite composite was used to eliminate formaldehyde from Razi petrochemical wastewater and was able to eliminate 91.24% of formaldehyde, 70% of COD, and 68.9% of BOD5. The isotherm and kinetic investigations demonstrated that the formaldehyde uptake process by the foresaid adsorbent follows the Langmuir isotherm and quasi-first-order kinetic models, respectively. Also, the maximum uptake capacity was obtained at 50.25 mg/g. Moreover, the formaldehyde uptake process by the aforementioned nanocomposite was exothermic and spontaneous. Furthermore, the formaldehyde adsorption efficiency decreased slightly after six reuse cycles (less than 10%), indicating that Alginate@Fe3O4@Bentonite nanocomposite has remarkable recyclability. Besides, the influence of interfering ions like nitrate, carbonate, chloride, phosphate, and sulfate was studied on the formaldehyde removal efficiency and the results displayed that all ions except nitrate ion have low interaction with formaldehyde (less than 3% reduction in removal efficiency).


Assuntos
Nanocompostos , Poluentes Químicos da Água , Bentonita/química , Alginatos/química , Águas Residuárias , Espectroscopia de Infravermelho com Transformada de Fourier , Nitratos/análise , Cinética , Nanocompostos/química , Adsorção , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise
18.
Environ Sci Pollut Res Int ; 30(9): 22728-22742, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36306072

RESUMO

Fresh tobacco or the smoke resulting from waterpipe and cigarette contains large amounts of polycyclic aromatic hydrocarbons (PAHs), which consumption can cause releasing of these contaminants into the indoor air of cigarette and waterpipe cafés. This study was conducted to investigate the urinary concentrations of unmetabolized PAH compounds among the employed workers as well as the customers in waterpipe and cigarette cafés along with its association with oxidative stress factors plus kidney injury biomarkers. For this, 35 staffs and 35 customers in these cafés (as an exposed group (EG)), 20 staffs in non-smoking cafés (as 1st control group (CG-1)), and 20 of the public population (as 2nd control group 2 (CG-2)) were chosen and their urine specimens were collected. The results indicated that there is a significant difference between urinary concentration of Æ©PAHs in the exposed and control groups (P value < 0.05). Also, "type of tobacco" can be considered as an influential and determining factor for the urinary levels of PAHs among the subjects. Considering the contribution of PAHs to the total toxic equivalents, benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DahA), and fluoranthene (Flrt) with 32.76%, 27.62%, and 18.65% claimed the largest share in waterpipe/cigarette cafés. The results also indicated a positive and significant relationship between some PAHs and oxidative stress biomarkers as well as uKIM-1 (biomarker for assessing and diagnosing glomerular damage) and TIMP-1 (biomarker of stress in primary steps of injury in tubular cell). Thus, it can be expressed that the workers of these smoking cafés are prone to the detrimental health impacts. Accordingly, proper policies and decisions should be taken to limit the activity of these cafés or proper protective strategies should be adopted to protect the health of exposed individuals.


Assuntos
Poluição do Ar em Ambientes Fechados , Hidrocarbonetos Policíclicos Aromáticos , Produtos do Tabaco , Fumar Cachimbo de Água , Humanos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Biológico , Nicotiana , Biomarcadores , Monitoramento Ambiental/métodos
19.
Chemosphere ; 311(Pt 2): 137049, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36336020

RESUMO

Cigarette butts (CBs) are one of the most commonly found types of litter contaminating the aquatic environment. However, the environmental risks posed by CBs need further investigation. In this study, the in-vivo toxic effects of various concentrations of CB leachates on juvenile (5.45 ± 1.36 gr and 7.08 ± 1.12 cm) fish (Periophthalmus waltoni) were evaluated. The LC50 values of CB leachate from smoked cigarette butts with tobacco (SCB) were 3.75, 3.0, 1.94, and 1.37 CBs/L in 24, 48, 72, and 96 h exposure times, respectively. The LC50 values for leachate of smoked CBs without tobacco (SF) were 7.58, 6.22, 4.73, and 2.9 CBs/L at 24, 48, 72, and 96 h exposure times, respectively. In the case of leachate from unsmoked filters (USF), LC50 values were 14.68, 12.44, 10.19, and 7.46 CBs/L in 24, 48, 72, and 96 h exposure time, respectively. The mean concentrations of heavy metals and polycyclic aromatic hydrocarbons in SCBs leachates were higher than in SF and USF leachates. Our findings report that even low concentrations of CBs leachates can led to lethality of P. waltoni and may pose a threat to their population density.

20.
Environ Sci Pollut Res Int ; 30(6): 16707-16718, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36184705

RESUMO

The main goal of the current investigation was to decontaminate ibuprofen (IBP) from hospital wastewater using sea mud as an H2O2 activator. Sea sludge was converted into catalysts at different temperatures and residence times in furnaces, and then tested in the removal of IBP, and the most efficient ones were reported for the production of catalysts. The catalyst was optimized at 400 °C and 3 h. SEM-mapping, FTIR, EDX, BET, and BJH experiments were used to characterize the catalyst. Experiments were done at two pulsed and continuous ultrasonication modes in a photoreactor, and their efficiencies were statistically compared. The designed variables included IBP concentration (10-100 mg/L), the catalyst concentration (0-3 g/L), pH (4-9), and time (10-90 min). The oxidation process had the maximum efficiency at pH 4, treatment time of 60 min, catalyst quantity of 5 g/L, and IBP content of 50 mg/L. The catalyst was recycled, and in the fifth stage, the removal efficiency of IBP was reduced to 50%. The amount of energy consumed for treating IBP laden-wastewater using the evaluated catalyst in two modes of continuous and pulsed ultrasonic was calculated as 102 kW h/m3 and 10 kW h/m3, respectively. IBP oxidation process was fitted with the first-order kinetic model. The system can be proposed for purifying hospital and pharmaceutical wastewaters.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Ibuprofeno/química , Peróxido de Hidrogênio/química , Sonicação , Fotólise , Poluentes Químicos da Água/análise
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