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1.
Environ Monit Assess ; 196(6): 517, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38710902

RESUMEN

Nowadays, the introduction of nutrients caused by human activities is considered an environmental issue and a significant problem in river basins and coastal ecosystems. In this study, the concentration of nutrients ( NO 3 - and PO 4 3 - ) in the surface water sources of the Maroon-Jarahi watershed in the southwest of Iran was determined, and the pollution status and health risk assessment were done. The average concentration of nitrate and phosphate in Ludab, Maroon, Zard, Allah, Jarahi rivers, and Shadegan wetland were obtained at 2.25-0.59, 4.59-1.84, 4.07-2.02, 5.40-2.81, 11.51-4.67, 21.63 and 6.20 (mg/l), respectively. A comparison of the results with the World Health Organization (WHO) limit showed that nitrate was lower than in all stations, but phosphate was higher than the limit in some stations of the Maroon, Allah, Jarahi rivers, and Shadegan wetland. Calculation of linear regression analysis showed significant positive relationships between nitrate and phosphate in all surface water sources (except Ludab) and based on the N/P ratio, nitrogen was estimated as the limiting factor in phytoplankton growth (N/P < 16). The evaluation of the status of the Nutrient pollution index (NPI) was observed as: Shadegan > Jarahi > Allah > Maroon > Zard > Ludab that the Jarahi River and Shadegan wetland were in the medium pollution class (1 < NPI ≤ 3) and other waterbodies were in the non-polluted to low pollution state (NPI < 1). Calculation of the chronic daily intake (CDI) showed that water body nutrients cause more non-carcinogenic health risks through the oral route than dermal exposure, and according to HI, children's health is more at risk than adults. Findings showed that surface water resources especially downstream of the Maroon-Jarahi watershed are at eutrophication risk, and to control the nearby human activities and as a result increase the nutrients in these water resources, measures should be taken.


Asunto(s)
Monitoreo del Ambiente , Nitratos , Ríos , Contaminantes Químicos del Agua , Irán , Contaminantes Químicos del Agua/análisis , Medición de Riesgo , Humanos , Ríos/química , Nitratos/análisis , Fosfatos/análisis , Humedales , Contaminación Química del Agua/estadística & datos numéricos , Nutrientes/análisis , Recursos Hídricos
2.
Environ Monit Assess ; 195(3): 376, 2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36757450

RESUMEN

This study investigated the contamination and health risk assessment of heavy metals and organophosphorus pesticides in single, double, and ratoon cropping of rice in Mazandaran province, north of Iran. A total of 17 sampling locations in rice farms were selected and soil and rice samples were collected from farms in 5 counties of Mazandaran. Soil and rice samples were then transferred to the lab for further analysis. The concentration of pesticides and heavy metals was then analyzed using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Mercury was analyzed using a Leco mercury analyzer. Target hazard quotient (THQ), total target hazard quotient (TTHQ), carcinogenic risk (CR), and total carcinogenic risk (TCR) in children and adults were used. Potential ecological risk also was used to test the possible hazards of heavy metals to the environment. Heavy metals concentration in rice and soil samples in different farming steps revealed different levels. THQ showed no considerable risk in consuming contaminated rice to adults and children considered, while TTHQ revealed potential non-carcinogenic risks. Ni had the most carcinogenic risks to target human groups, and TCR showed carcinogenicity for carcinogenic heavy metals in all stations. Findings showed no ecological risks of metals to the environment. In conclusion, rice farmers in Mazandaran use the lands multiple times during the year to increase the performance, function, quality, and quantity of rice, but the possible toxic effects of heavy metals and pesticides on consumers and the environment should not be overlooked.


Asunto(s)
Mercurio , Metales Pesados , Oryza , Plaguicidas , Contaminantes del Suelo , Adulto , Niño , Humanos , Oryza/química , Compuestos Organofosforados/análisis , Monitoreo del Ambiente , Plaguicidas/análisis , Irán , Contaminación de Alimentos/análisis , Metales Pesados/análisis , Suelo/química , Carcinógenos/análisis , Mercurio/análisis , Medición de Riesgo , Receptores de Antígenos de Linfocitos T , Contaminantes del Suelo/análisis
3.
Environ Geochem Health ; 41(6): 2649-2663, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31098950

RESUMEN

Atmospheric elements released into the atmosphere can enter the human body through inhalation, ingestion and dermal contact and are then deposited in the body. Trace elements have potential risks to human health. For this purpose, the particulate matter accumulated by car air filters (CAFs) was studied. The morphology and distribution of particle size were examined using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The concentration of elements in CAFs and CAF-estimated air for 30 elements in Tehran, Iran, was analyzed in winter and summer, from February to July 2017. Samples were determined by inductively coupled mass plasma spectrometry. The most abundantly detected elements in both CAFs and air in both seasons were Ca, Mg, Na and Fe. The shape of the particles was mostly irregular and spherical. Most of the particles were between 0.5 and 1.0 µm. The carcinogenic risks of inhalation exposure to Cr and Co in winter and summer were higher than the acceptable level (< 1 × 10-4) for children and adults. The carcinogenic risks of As and Cr in both seasons were higher than 1 × 10-4 for children and adults via dermal contact. Also, the carcinogenic risks of Cr in both seasons of ingestion exposure were higher than 1.00E-04 for children and adults. The integrated noncarcinogenic risks of all trace elements were higher than the safe level (= 1) for children and adults in both seasons.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Exposición por Inhalación/efectos adversos , Material Particulado/análisis , Adulto , Filtros de Aire , Automóviles , Carcinógenos/análisis , Carcinógenos/toxicidad , Niño , Monitoreo del Ambiente/métodos , Humanos , Irán , Metales/análisis , Metales/toxicidad , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Material Particulado/toxicidad , Medición de Riesgo , Estaciones del Año , Espectrometría por Rayos X
4.
Biomed Chromatogr ; 31(5)2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27770444

RESUMEN

Preconcentration of trace amounts of diazinon by carbon mesoporous CMK-3 in water and biological samples and measurement by high-performance liquid chromatography were investigated. CMK-3 was prepared using hexagonal SBA-15 as the template. The synthesized materials were characterized by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy, Brunaur-Emmet-Teller, transmission electron microscopy and Boehm titration method. The preconcentration procedure was optimized using a multivariate optimization approach following a two-stage process. The effect of analytical parameters including the amount of the CMK-3 as an adsorbent, pH, type and volume of eluent and flow rate of eluent and sample were studied by a screening project, then the effective parameters were optimized by response surface methodology based on central composite design. The average extraction efficiency of diazinon under optimal conditions (CMK-3 dosage = 25 mg, sample flow rate = 2.5 mL min-1 , eluent flow rate = 1.25 mL min-1 , volume of methanol as an eluent =3.5 mL and initial pH = 6) was 97.11%, which agrees well with the predicted response value (97.93%). The linearity of the method was in the range of 0.5-100 µg L-1 with a correlation coefficient of 0.997. Enrichment factor, limit of detection and limit of quantification were 285.7, 0.09 and 0.23 µg L-1 , respectively. The relative standard deviation (RSD) under optimum conditions was 2.21% (n = 5). The proposed method was applied to determine diazinon in real water and biological samples. Recovery of diazinon from real samples was between 95.80 and 104.94% with an RSD of 0.19-4.65%. Thus, this method is suitable for the preconcentration and determination of diazinon in real water and biological samples.


Asunto(s)
Técnicas de Química Analítica/métodos , Diazinón/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Carbono/química , Técnicas de Química Analítica/instrumentación , Diazinón/sangre , Diazinón/química , Humanos , Concentración de Iones de Hidrógeno , Irán , Límite de Detección , Microscopía Electrónica de Transmisión , Nitrógeno , Dióxido de Silicio/química , Extracción en Fase Sólida/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/química , Difracción de Rayos X
5.
Biomed Chromatogr ; 30(8): 1256-62, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26683457

RESUMEN

Palm leaf ash was characterized and used as low-cost adsorbent for solid-phase extraction and preconcentration of bisphenol A (BPA) in real water samples. Analysis of BPA was carried out using HPLC involving Eurospher 100-5-C18 (25 cm × 4.5 mm, particle size 5 µm) column and water-acetonitrile (40:60, v/v) as mobile phase. The adsorption was achieved quantitatively at a pH of 6 with elution by 3 mL acetonitrile. The limits of detection and enrichment factor were 0.02 µg L(-1) and 333, respectively. Under optimum conditions the relative standard deviation (RSD) was 2% (n = 10). Comparison of qualification criteria of presented preconcentration procedure with other research indicated that palm leaf ash adsorbent was better than many of the adsorbents in terms of cost and reusability. Also, the limit of detection, precision and enrichment factor were comparable and even better than the previously reported methods. Finally, the efficiency of method was computed by determination of trace amounts of BPA in sea, river, mineral and tap waters with recoveries of 93.3-105.5% and RSDs of 0.61-3.12%.. Briefly, the developed solid-phase extraction and Preparative layer chromatography (PLC) methods may be used for bisphenol A monitoring in any environmental water sample. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Compuestos de Bencidrilo/análisis , Cromatografía Líquida de Alta Presión/métodos , Fenoles/análisis , Phoeniceae/química , Hojas de la Planta/química , Contaminantes Químicos del Agua/análisis , Adsorción , Espectrofotometría Ultravioleta
6.
Environ Monit Assess ; 187(1): 4082, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25492705

RESUMEN

The Hara Mangrove Forest of the Persian Gulf is undergoing increasing pollution from industrial, municipal, and petroleum sources; however, little research in ecotoxicology has been carried out in this ecosystem. In the present study, mercury distribution and accumulation were investigated in muscle, liver, kidney, and feather of the resident Western reef heron (n = 15) and the migratory Siberian gull (n = 15). We also evaluated the relation between Hg concentrations, sex, and age (juvenile vs. adult). Results showed that the highest concentrations of Hg were recorded in the feather (35 ± 0.14-3.0 ± 0.27 mg kg(-1) dw) and at 3.7-, 1.6-, and 1.3-fold in muscle, kidney, and liver, respectively. Concentrations of mercury in tissues of migratory birds were two times higher than in resident birds; geographical differences and feeding habits were used to explain these variations. We found a weak relationship between Hg concentrations in feathers and internal tissues (r ≤ 0.50); conversely, liver presented strong positive correlations with other soft tissues, especially kidney (p > 0.05; r = 0.82). Results showed that sex and age have no significant effects on T-Hg accumulation in these birds (p > 0.05; r < -0.01). Based on these findings, Hg concentrations were low in both species. Therefore, Hg contamination of this aquatic ecosystem is not a threat. Accordingly, we recommend the use of the Western reef heron as a bioindicator of mercury pollution in this region.


Asunto(s)
Aves/metabolismo , Monitoreo del Ambiente , Contaminantes Ambientales/metabolismo , Mercurio/metabolismo , Humedales , Migración Animal , Animales , Charadriiformes/metabolismo , Ecotoxicología , Contaminantes Ambientales/análisis , Contaminación Ambiental , Plumas/química , Plumas/metabolismo , Femenino , Océano Índico , Riñón/metabolismo , Hígado/metabolismo , Masculino , Mercurio/análisis
7.
Artículo en Inglés | MEDLINE | ID: mdl-23802166

RESUMEN

The application of coagulation-flocculation (CF) process for treating the paper-recycling wastewater in jar-test experiment was employed. The purpose of the study was aimed to examine the efficiency of alum and poly aluminum chloride (PACl) in combination with a cationic polyacrylamide (C-PAM) in removal of chemical oxygen demand (COD) and turbidity from paper-recycling wastewater. Optimization of CF process were performed by varying independent parameters (coagulants dosage, flocculants dosage, initial COD and pH) using a central composite design (CCD) under response surface methodology (RSM). Maximum set required 4.5 as pH, 40 mg/L coagulants dosage and 4.5 mg/L flocculants dosage at which gave 92% reduction of turbidity, 97% of COD removal and SVI 80 mL/g. The best coagulant and flocculants were alum and chemfloc 3876 at dose of 41 and 7.52 mg/L, respectively, correspondingly at pH of 6.85. These conditions gave 91.30% COD and 95.82% turbidity removals and 12 mL/g SVI.


Asunto(s)
Modelos Teóricos , Eliminación de Residuos Líquidos/métodos , Resinas Acrílicas/química , Compuestos de Alumbre/química , Hidróxido de Aluminio/química , Análisis de la Demanda Biológica de Oxígeno , Floculación , Concentración de Iones de Hidrógeno , Residuos Industriales , Nefelometría y Turbidimetría , Papel , Reciclaje , Aguas Residuales/análisis , Aguas Residuales/química
8.
Bull Environ Contam Toxicol ; 90(3): 285-90, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23248032

RESUMEN

Organochlorine pesticides (OCPs) and PCBs were determined in water and sediment from the Anzali Wetland, north of Iran. The total concentrations of OCPs were 71.75-315.16 ng/l, 1.8-12.68 ng/g dry wt in water and sediments respectively, and those of polychlorinated biphenyls (PCBs) in the two phases were: nd-141.09 ng/l and 0.39-2.64 ng/g dw, respectively. Also, the results indicated that ß-HCH, DDE were the most common organochlorine pesticides contaminants. In this study, the ∑PCB/∑DDT reflect the relative importance of agricultural than industrial sources in this area. a significant difference was observed between the stations. Station number 3 showed the highest range of the pollutants studied.


Asunto(s)
Monitoreo del Ambiente/métodos , Sedimentos Geológicos/análisis , Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Contaminantes Químicos del Agua/análisis , Humedales , Internacionalidad , Irán , Bifenilos Policlorados/análisis , Extracción en Fase Sólida
9.
Bull Environ Contam Toxicol ; 90(5): 578-84, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23429963

RESUMEN

Phenolic endocrine disrupting chemicals are environmental pollutants with xenostrogen effects in wildlife and humans. The aim of this study was to determine 4-nonylphenol, Octylphenol, and Bisphenol A residues in various tissues of carp fish samples from Anzali wetland, Iran. 4-NP, OP, and BPA were detected with GC-MS in the muscle of fish from sampling location with maximal concentrations of 8.17, 9.67 and 5.87 µg/gdw, respectively. The highest concentrations of these compounds were found in the liver by HPLC. Since many endocrine disrupting substances were significantly lipophilic, distributing of these compounds into fish tissue has been correlated with lipid content.


Asunto(s)
Carpas/metabolismo , Disruptores Endocrinos/metabolismo , Monitoreo del Ambiente , Contaminantes Químicos del Agua/metabolismo , Humedales , Animales , Compuestos de Bencidrilo/metabolismo , Irán , Hígado/metabolismo , Músculos/metabolismo , Fenoles/metabolismo , Contaminación Química del Agua/estadística & datos numéricos
10.
J Mol Recognit ; 25(7): 404-13, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22733549

RESUMEN

For the first time in this work, uniform molecularly imprinted polymer (MIP) nanoparticles were prepared using nalidixic acid as a template. The MIP nanoparticles were successfully synthesized by precipitation polymerization applying methacrylic acid (MAA) as a functional monomer and trimethylolpropane trimethacrylate (TRIM) as a cross-linking monomer at different mole ratios. The morphology, binding, recognition, selectivity, and in vitro release behaviors of obtained particles were studied. The produced polymers were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetric. Furthermore, their morphology was analyzed accurately by scanning electron microscopy, photon correlation spectroscopy, and Brunauer-Emmett-Teller analysis. The nanospheres and microspheres with mean diameter values of 94 nm, 256 nm, and 1.2 µm were obtained using nalidixic acid-MAA-TRIM various mole ratios. Among the MIPs, the product with nalidixic acid-MAA-TRIM mole ratio of 1:12:12 established nanospheres with the lowest polydispersity index (0.003), an average pore diameter (12 nm), and the highest specific surface area (280 m(2) g(-1)) and selectivity factor (10.4). Results from binding experiments demonstrated that the imprinted nanospheres with a 94-nm mean diameter and a binding capacity of 28 mg of nalidixic acid per gram of polymer had higher specific affinity to nalidixic acid in contrast with the other imprinted nanospheres, microspheres, and nonimprinted particles. However, the binding performance of imprinted nanospheres in human serum was estimated using high-performance liquid chromatography analysis (binding approximately 98% of nalidixic acid). In addition, release experiments proved to be successful in the controlled release of nalidixic acid during a long period. The 20% of loaded nalidixic acid was released from the imprinted nanospheres within the first 20 h, whereas the remaining 80% was released in the after 120 h. The nalidixic acid release kinetics from the MIPs was highly affected by properties of the particles.


Asunto(s)
Investigación Biomédica , Precipitación Química , Técnicas de Química Analítica , Portadores de Fármacos/síntesis química , Ácido Nalidíxico/administración & dosificación , Nanosferas , Investigación Biomédica/instrumentación , Investigación Biomédica/métodos , Materiales Biocompatibles Revestidos/síntesis química , Materiales Biocompatibles Revestidos/farmacocinética , Materiales Biocompatibles Revestidos/farmacología , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Humanos , Metacrilatos/química , Metacrilatos/farmacología , Microtecnología/métodos , Impresión Molecular/métodos , Ácido Nalidíxico/metabolismo , Ácido Nalidíxico/farmacocinética , Nanosferas/química , Tamaño de la Partícula , Polimerizacion , Análisis Espectral
11.
Environ Monit Assess ; 184(1): 375-80, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21494835

RESUMEN

Human milk is usually the only source of food for infants during the first 4 to 5 months of their life. Maternal environmental mercury exposure is directly related to fish consumption or amalgam filling. In this research, 38 human milk samples were collected from mothers of Lenjan area who were not occupationally exposed with mercury. Mercury concentration in human milk was determined by AMA254 Mercury Analyzer. A level of mercury was examined in relation to somatometric, demographic and dental amalgam parameters. Obtained results showed that only dental amalgam significantly increased the mercury level in human milk (p < 0.001). The mean mercury concentrations in milk of mothers without teeth fillings (n = 13), with one to three teeth fillings (n = 10), and four to eight teeth fillings (n = 15) were 2.87, 5.47, and 13.33 µg/l, respectively. The result of this study also showed a positive correlation of mercury milk levels with the number of teeth fillings of the mother (p < 0.05, r = 0.755). The estimated weekly intake of mercury of a breastfed infant in this study was, in some cases, higher than provisional tolerance weekly intake recommended by FAO/WHO, which pose a threat to their health.


Asunto(s)
Amalgama Dental/química , Mercurio/química , Leche Humana/química , Humanos , Irán , Mercurio/metabolismo
12.
Environ Monit Assess ; 184(5): 3231-7, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21713472

RESUMEN

The Anzali Wetland is one of the most important ecosystems in the north of Iran, and parts of it were registered as a Ramsar site in 1975. However, even though, due to many problems, including eutrophication produced by inflow of excess nutrients and organic materials, the wetland was also listed on the Montreux Record indicating the need to take urgent remedial action. This study was conducted to study the levels of polychlorinated biphenyls (PCBs) and total mercury (THg) in two fish species (Esox lucius and Carassius auratus) as bio-indicators of the ecosystem condition in eastern part of Anzali Wetland. The sampling was carried out in six different periods between years 2009 and 2010. The results showed that the amounts of PCBs in the muscle of northern pike were below the detection limit of gas chromatography, whereas the average concentration in goldfish was 0.449 mg/kg wet weight. Some possible reasons for the higher levels of PCBs in goldfish in comparison with pike have been discussed. No significant (p < 0.05) correlation was observed between PCBs and biological factors (weight, length, lipid content) for both species. On the other hand, the mean concentration of THg in the muscle of pike and goldfish were 182.22 and 75.27 ng/g dry weight, respectively. Although these concentrations were below US-EPA criterion for human consumption (0.3 mg/kg), it pointed up a significant deterioration of the ecosystem condition during the past years. Finally, statistical analysis revealed a significant correlation between THg with weight and an insignificant correlation with length for pike specimens.


Asunto(s)
Peces/metabolismo , Mercurio/metabolismo , Bifenilos Policlorados/metabolismo , Contaminantes Químicos del Agua/metabolismo , Humedales , Animales , Monitoreo del Ambiente , Irán , Mercurio/análisis , Bifenilos Policlorados/análisis , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/estadística & datos numéricos
13.
Bull Environ Contam Toxicol ; 88(1): 60-4, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22057228

RESUMEN

Much of the variation in trace metal tissue concentrations in marine invertebrates has been attributed to the variety in individual organism size, age and sex. This study assessed the relationship between total mercury (Hg) concentrations in edible tissue, exoskeleton and viscera with length, weight and gender for 69 samples of crustaceans, Penaeus semisulcatus (n = 30), Thenus orientalis (n = 21) and Portunus pelagicus (n = 18) from the northern part of the Persian Gulf. Significant increase in the Hg level in muscle and viscera (r > 0.65, p < 0.01) with an increase in length and weight for all three species. No relationship was found between the Hg level in exoskeleton and length or weight. Significantly higher Hg levels (p < 0.01) were found in female P. semisulcatus than in males (muscle and viscera), but no gender differences were found for the other two species.


Asunto(s)
Crustáceos/metabolismo , Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Braquiuros/crecimiento & desarrollo , Braquiuros/metabolismo , Crustáceos/crecimiento & desarrollo , Monitoreo del Ambiente , Femenino , Océano Índico , Irán , Masculino , Palinuridae/crecimiento & desarrollo , Palinuridae/metabolismo , Penaeidae/crecimiento & desarrollo , Penaeidae/metabolismo , Contaminación Química del Agua/estadística & datos numéricos
14.
Bull Environ Contam Toxicol ; 88(4): 614-6, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22323045

RESUMEN

In this study, Arsenic (As) was measured in several varieties of imported and local cultivated rice. Soil samples collected from rice farms situated in south Caspian Sea (Iran) were also studied. The mean concentration of As in imported rice, local farmed rice and soil, were determined as 0.28, 0.39 and 3.80 µg g(-1) dry weight, respectively. Estimated daily intake of As through human consumption of imported and local produced rice was 0.77 and 1.074 µg day(-1) kg(-1) B.W., respectively. These values are much lower than the tolerable daily intakes estimated by JECFA. The As concentration in the soil (3.80 µg g(-1) dry) was below acceptable limit for agricultural soil of 20.0 mg kg(-1) as recommended by the European Community (EC). No correlation between the As concentrations in rice and soil samples was found (p > 0.05).


Asunto(s)
Arsénico/análisis , Contaminación de Alimentos/análisis , Oryza/química , Contaminantes del Suelo/análisis , Dieta/estadística & datos numéricos , Monitoreo del Ambiente , Contaminación de Alimentos/estadística & datos numéricos , Humanos , Irán , Océanos y Mares , Suelo/química
15.
J Environ Public Health ; 2022: 4593835, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35355855

RESUMEN

Crystals of malachite green (MG), being water-soluble, are effective agents applied to combat fungal and parasitic infections in fish. This study was conducted to evaluate the adsorption of MG as a cationic dye by polymeric resin Amberlyst 15. Changes in several parameters were observed, including the concentration of MG, pH, the adsorption rate and extent, and the temperature that might all affect the efficiency of adsorption. The adsorption method was described well by both the Redlich-Peterson and Langmuir isotherms with R 2 of 0.9933 and 0.9880, respectively. The kinetic information is consistent with the Freundlich isotherm model and pseudo-2nd-order kinetics model. Analysis of malachite green was executed by HPLC containing a Eurospher 100-5 C18 (25 cm × 4.5 mm, size of particle 5 µm) column, UV detector was set at 618 nm, and 125 mM ammonium acetate was adapted to pH 4.5 with formic acid-acetonitrile (45 : 55, v/v) as the moving phase. The limit of the discovery factor was 0.02 µgL. The negative value of ΔG° reveals the spontaneity of the absorption method. The positive value of ΔS° (333.1253 J/K mol) gives back randomness at the solid-liquid interface of sorption. The required adsorbent concentration was calculated for removing MG up to an extraction efficiency of 98.27% after 240 minutes.


Asunto(s)
Resinas de Intercambio Iónico , Colorantes de Rosanilina , Adsorción , Concentración de Iones de Hidrógeno , Colorantes de Rosanilina/química
16.
Chemosphere ; 297: 133992, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35247450

RESUMEN

In this study, an attempt was made to synthesize metal-organic frameworks (MOFs) based magnetic iron particles as photocatalysts for textile dye wastewater. Improvement strategy was a novel two-step dry method without using conventional methods to eliminate the consumption of chemical reagents. First, the heterogeneous photocatalyst of Fe-MOFs derived magnetic carbon nanocomposite with carboxylic acid surface functional groups (Fe@C-COOH) was achieved. Next, the α-Fe2O3@C@SiO2/TiO2 was successfully synthesized followed by a sol-gel method to coat the SiO2 shell and a solvothermal method to coat the surface of the intermediate TiO2 particles. The as-synthesized nanocomposite materials were characterized and physicochemical analytical equipment. Further, the investigation on magnetic photocatalytic nanocomposite α-Fe2O3@C@SiO2/TiO2 performance of dye degradation and photocatalytic activity on Reactive yellow 145 (RY145), using as an indicator was conducted. The as-synthesized nanocomposite particles were characterized using X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), X-ray energy dispersive spectroscopy (EDX), and scanning electron microscopy (SEM) techniques. The structural characterization of the as-synthesized materials proved that these methods generate oxygen-containing functional groups, such as, -OH, -CO, and -COOH, which increases the polarity and hydrophilicity of the photocatalyst. The photocatalytic oxidation of RY145 dye under UVc light was discussed by the apparent first-order reaction rate and the kinetic model of the Langmuir-Hinshelwood followed a better fitting. The optimal performance of the composite is at pH = 2, 15 mg/100 mL of photocatalyst dose, 150 mg/L concentration of the dye RY145 at 25 °C temperature under UVc lamp irradiation for 90 min, and with the apparent reaction rate constant was 0.0165 min-1. The thermodynamic analysis of activation parameters computed by the Eyring model and based on transition state theory (TST), an endothermic reaction with a positive value for Δ‡Ho (50.16 kJ mol-1) and a negative value for Δ‡So (-153 J/mol K) both contribute toward achieving positive values for Δ‡Go and a nonspontaneous process. The proposed α-Fe2O3@C@SiO2/TiO2 demonstrated a high capability of photocatalytic degradation up to 97% after five successive cycles at the optimal condition compared to that of Fe3O4@C (18.74%) and Fe@C-COOH (77.9%) without reusability.


Asunto(s)
Estructuras Metalorgánicas , Nanocompuestos , Purificación del Agua , Catálisis , Compuestos Férricos , Nanocompuestos/química , Dióxido de Silicio/química , Espectroscopía Infrarroja por Transformada de Fourier , Titanio/química
17.
Environ Monit Assess ; 175(1-4): 469-74, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20556646

RESUMEN

The objective of this study was to investigate the presence of organochlorine pesticides (α-HCH, ß-HCH, γ-HCH, HCB, dieldrin, o,p'-DDE, p,p'-DDE, p,p'-DDD, p,p'-DDT) and polychlorinated biphenyl (PCBs) congeners (28, 52, 101, 138, 153, 180) in pasteurized and sterilized milk containing 1.5%, 2.5%, and 3% fat from Tehran province (Iran). Considering the importance of milk and dairy products for human nutrition and the toxicity of these compounds, their daily intake (DI) through milk was also determined. The compounds γ-HCH (13.49 ng g(-1) fat), ß-HCH (11.7 ng g(-1) fat), and PCB180 (7.56 ng g(-1) fat) were found at highest concentrations. The DI for all compounds was less than the acceptable daily intake established by FAO/WHO except for Σ PCBs which was more than the minimal risk level.


Asunto(s)
Hidrocarburos Clorados/análisis , Leche/química , Plaguicidas/análisis , Bifenilos Policlorados/análisis , Animales , DDT/análisis , Diclorodifenil Dicloroetileno/análisis , Diclorodifenildicloroetano/análisis , Monitoreo del Ambiente , Hexaclorociclohexano/análisis
18.
Bull Environ Contam Toxicol ; 87(6): 678-83, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21979141

RESUMEN

Feather and muscle of 10 avian species (n = 46), were analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Muscle contained significantly higher PCB and OCP than liver and feather. Mean muscle and feather PCB was 408.5 ± 134.5 and 32 ± 4.5 ng/g wet weight. Highly chlorinated PCBs were found in muscle and liver while feather had PCBs with less chlorination. Gulls had highest levels of both pollutants. Gull feather PCB and OCP were strongly correlated with their levels in the liver and muscle tissues (0.6 < r < 0.9, p < 0.01). Analysis of gull feather can be used as a non-invasive method for monitoring organic pollutants.


Asunto(s)
Aves , Monitoreo del Ambiente/métodos , Plumas/química , Músculos/química , Contaminantes Químicos del Agua/análisis , Animales , Sustancias Peligrosas/análisis , Hidrocarburos Clorados/análisis , Irán , Océanos y Mares , Plaguicidas/análisis , Bifenilos Policlorados/análisis , Distribución Tisular
19.
Environ Sci Pollut Res Int ; 28(8): 9276-9289, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33140304

RESUMEN

The objective of this research was to determine seasonal variation, distribution, potential health risk, and source identification of 16 polycyclic aromatic hydrocarbons (PAHs) in the surface dust of eight urban areas of Qom. The total levels of 16 PAHs ranged from 364.83 to 739.26 ng g-1, with an average of 478.27 ng g-1. Sites 1 and 8 showed the highest (491.33 ng g-1) and lowest (465.08 ng g-1) concentrations of PAHs, respectively. The PAHs demonstrated the highest and the lowest levels in autumn (553.41 ng g-1) and summer (402.30 ng g-1), respectively. Naphthalene (Nap) showed the highest amounts in all of the areas (75.57 ng g-1). Source apportionment indicated that vehicular emissions and combustion of fossil fuels (liquid fossil fuel, crude oil, and gas) are the main sources of the PAHs. Toxic equivalency quantities (TEQs) index exhibited a mean concentration of 47.41 ng g-1, and benzo[a]pyrene (BaP) and dibenzo[a,h]anthracene (DBA) together contributed more than 80% of TEQ, indicating high risk potential of these compounds. Total incremental lifetime cancer risk (ILCR) presented higher value (2.62 × 10-7) for children than for adults (2.53 × 10-7), one-fold lower than the threshold (10-6). The spatial ILCR for the study areas and seasons showed the highest cancer risk in site 2 and winter. Taken together, the carcinogenic risk of PAHs to children and adults, respectively, through direct ingestion and dermal contact pathways illustrated values close to the baseline, suggesting that more attention should be paid to the issue in the study area.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Adulto , Niño , China , Polvo/análisis , Monitoreo del Ambiente , Humanos , Irán , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo
20.
Ecotoxicology ; 19(6): 997-1002, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20596768

RESUMEN

An evaluation of suitability of applying hair as a noninvasive indicator for determination of the body burden mercury in mammals was carried out by determining the concentration of mercury in hair and liver tissue of the golden jackal, Canis aureus . Nineteen jackals killed on the roads along the Caspian Sea in the central region of Mazandaran Province, Iran were collected. The mercury measurements were carried out by AMA254 LECO and the standard method ASTM-D6722. SPSS and Excel were used for analytical statistics. There was a significant difference in Hg levels between the hair and liver tissue (P < 0.001). The average concentration of mercury was 187.3 + or - 22.7 and 53.3 + or - 7.3 ng/g, respectively. No significant differences were seen either between the sexes or in correlation between the tissues. But a significant and positive relation was seen between the mercury content in hair and body weight and length (P < 0.005). In general, the mercury concentration was less than the deleterious, effective limit on the species. It seems that this is the first study of Hg concentrations in jackals and demonstrates on easy and noninvasive sampling method.


Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/metabolismo , Cabello/metabolismo , Chacales/metabolismo , Mercurio/metabolismo , Animales , Tamaño Corporal , Femenino , Chacales/anatomía & histología , Hígado/metabolismo , Masculino
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