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1.
Environ Monit Assess ; 193(7): 418, 2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34120273

RESUMO

Mexican Lake Chapala is used as water supply for human consumption. Consequently, water quality of this lake is of paramount importance for the lake's wellbeing. The contribution presented in this paper investigates monitoring and assessment of lake water quality using water quality index (WQI), metal chemical speciation, and multivariate statistical techniques. Descriptive statistics shows total metal concentrations undetected conferring the lake a healthy status. Dissolved Cd and Pb exceed criterion continuous concentration limit, whereas Zn is below this limit indicating that water quality is satisfactory for aquatic life. However, WQI indicates poor water quality attributed to failure of conductivity, total solids, nitrogen, and phosphates, due to industrial and agro-industrial effluents. Metal speciations indicate that the presence of low concentrations of dissolved metals reflect interactions with gills of fish through metal-biotic ligand complexes affecting water quality. Positive correlations are obtained between conductivity and nitrates, indicating that agricultural activities and fertilizer runoffs increase the conductivity and that the environmental state of lake is being altered by human activities. Factors F1 (31%), F2 (19%), and F3 (11%) represent 61% of variability; F1 and F2 corroborate the pressure exerted by pollutants related with fertilizers and agrochemicals; F3 contains Zn and Pb with positive loads attributed to influx of tourist visitors. Sites S4, S5, S6, and S9 are identified as the most environmentally affected by COD, Alk*, pH, Cl-, nitrites, phosphates, and TS. Multivariate techniques permit to conclude that environmental stress of Lake Chapala is caused by variables pertaining to agrochemical, fertilizers and municipal wastes.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Humanos , Lagos , Metais Pesados/análise , México , Poluentes Químicos da Água/análise , Qualidade da Água
2.
Environ Monit Assess ; 193(7): 407, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34110511

RESUMO

Urban development has positive and negative effects on the evolution of enclosed lake water quality. This study aims to quantitatively analyze the water quality evolution of a typical urban lake, the Sha Lake, in the process of urban development. The land use degree comprehensive index (I) was calculated to reveal the level of urban development; water quality index (Smid) and eutrophication index (Tmid) were used to evaluate the water quality changes by fuzzy comprehensive-quantifying assessment (FCQA) method. The urban construction process and the water quality changes in 2000-2018 in the Sha Lake Basin were divided into three stages: (1) in 2000-2006, with the slow urban development, water quality remained stable and the degree of eutrophication improved slightly; (2) in 2007-2009, I increased rapidly to reach 300, Smid and Tmid increased from 90.62 to 92.83 and 75.06 to 87.52, respectively. Water quality deteriorated because of the failure to implement environmental protection measures in time; (3) in 2010-2018, although urban development reached a high level (I > 300), the water network connection project, dredging project, exogenous pollutant control, and sewage pipe network renovation since 2009 were critical measures to improve water quality for a long time. Due to the lag effect on improving water quality, the implementation of environmental protection measures should be synchronized with or even before urban construction. The research results can provide a scientific basis for the urban lake water environment protection in the process of urban development.


Assuntos
Lagos , Poluentes Químicos da Água , China , Monitoramento Ambiental , Eutrofização , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise , Qualidade da Água
3.
Environ Monit Assess ; 193(7): 409, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34114093

RESUMO

Brazil has one of the greatest hydroelectric potential in the world with high number of reservoirs for the electricity generation. However, little is known about the influence of these environments on the water quality. The water quality monitoring data from 14 stations distributed throughout the Irapé HPP reservoir (lentic environment), and its main tributaries (lotic environment), between the years 2008 and 2018, were evaluated and compared to assess the spatial variability of water quality. The analyzed parameters included total alkalinity, thermotolerant coliforms, electric conductivity, biochemical oxygen demand, dissolved iron, total phosphorus, nitrate, total ammoniacal nitrogen, dissolved oxygen, pH, total dissolved solids, sulfate, water temperature, and turbidity. Cluster analysis (CA), Kruskal-Wallis (KW) tests, Spearman rank-order correlation, and principal component analysis (PCA) were applied to identify and compare the relationship between the main parameters in the lotic and lentic environments. The CA resulted in four clusters according to proximity and the environment type (lotic or lentic). In general, the water quality showed better conditions in the reservoir and in the lotic stations on the immediate surround. The results may be associated with the greater sedimentation in the lentic environment. The analyses indicated that agricultural activities and the geochemical characteristics of the region are the main responsible for changes in the water quality.


Assuntos
Poluentes Químicos da Água , Qualidade da Água , Brasil , Monitoramento Ambiental , Fósforo/análise , Análise de Componente Principal , Rios , Poluentes Químicos da Água/análise
4.
Braz J Biol ; 82: e234692, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105659

RESUMO

The Gravataí River basin, one of the main water sources of the metropolitan region of Porto Alegre, is among the ten most polluted rivers in Brazil. Water quality is monitored only through physico-chemical and microbiological parameters in Brazil, and in this context, considering the importance of the use of biomarkers in complementing the analysis of water, the present study aimed to evaluate the environmental quality of the main affluent of the Gravataí River, Demetrio stream, through physico-chemical, microbiological, and cytogenotoxic criteria, at the stream source (P1), whereas samples P2 and P3 were obtained from the upstream near the area with the highest urban density and the downstream near the meeting point with the Gravataí River, respectively. The results for copper concentration and color classified the Demetrio stream as Class 4 in general, that is, the water is suitable only for navigation and to landscape harmony. The main genotoxic alterations (micronuclei and nuclear buds) were observed in P2, in which were obtained the highest levels of copper, in addition to iron and manganese. Anthropic interventions were observed in P1 and P2; however, due to its low metal concentration, P3, near the Gravataí River, manifested an improvement in environmental quality.


Assuntos
Poluentes Químicos da Água , Qualidade da Água , Brasil , Monitoramento Ambiental , Rios , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
5.
J Hazard Mater ; 415: 125705, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34088190

RESUMO

The objective of this study was to improve the mineralization of metronidazole, a recalcitrant antibiotic by the development of a new combined process coupling electro-Fenton and a biological process. For biotreatment, various strategies were considered bioaugmentation, bioacclimatation and biostimulation alone or combined. So, the novelty of this strategy is to combine advanced oxidation process with advanced biological process. The conventional biotreatment with activated sludge after 120 h of culture, led to 58.1% mineralization, whereas the pure isolated strains, from activated sludge culture in the presence of metronidazole by-products, identified as Pseudomonas putida (strain A) and Achromobacter sp. (strain B), led to 37.2% and 40.1% respectively. After original acclimation of the isolated strains to electrolysis by-products, the mineralization levels reached 75.6% and 72.9% for strains A and B respectively after 120 h of culture. The results showed that the mineralization of metronidazole by-products was the most important in the case of the combination of autochthonous bioaugmentation and biostimulation, with 96.1% after 120 h of treatment. By coupling the two processes, the global treatment reached therefore a mineralization yield of 97% with a reduction in processing time of 16 days compared to previous conventional biological treatment.


Assuntos
Fenômenos Biológicos , Preparações Farmacêuticas , Poluentes Químicos da Água , Eletrólise , Peróxido de Hidrogênio , Metronidazol , Oxirredução , Poluentes Químicos da Água/análise
6.
J Hazard Mater ; 415: 125749, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34088204

RESUMO

Biochar prepared from sludge and liriodendron leaves (SLAC) was modified by Fe3+ (SLAC-Fe), and they were used to remove methyl orange (MO) from single system and aqueous solution with Cr6+. The physical and chemical properties of biochar were characterized by BET, SEM, TEM, EDS, FTIR and XPS. The influences of initial MO concentration, adsorbent dose, pH, contact time and temperature on the adsorption of MO by biochar were investigated. The results indicated that SLAC-Fe had a higher removal efficiency for MO than SLAC. In the binary system, the maximum adsorption capacities of MO were 0.26 and 0.22 mmol/g with Cr6+ concentrations of 0.2 and 0.8 mmol/L, respectively. The adsorption kinetic model of pseudo-second-order fitted well with the experimental data of MO in single system. The equilibrium experimental data of MO in single and binary component systems were fitted well to Freundlich isotherm models. It was based on chemical and multilayer adsorption. It could be concluded that there was a competitive adsorption between Cr6+ and MO. The reason was that the HCrO4- and Cr2O72- competed with SO3- for the effective adsorption sites on the surface of SLAC-Fe, resulting in a reduction in the adsorption capacity of MO.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Compostos Azo , Carvão Vegetal , Concentração de Íons de Hidrogênio , Ferro , Cinética , Poluentes Químicos da Água/análise
7.
Environ Monit Assess ; 193(7): 402, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34109456

RESUMO

The disordered growth of large cities around water bodies causes environmental damage due to discarded plastics and microplastics (MPs) that aquatic organisms can ingest. This study analyzed the occurrence, type, and abundance of MPs in the gastrointestinal contents of four species of commercial fish (120 total specimens), namely, Brazilian mojarra (Eugerres brasilianus) and mullets (Mugil curema, Mugil curvidens, and Mugil liza), obtained in Porto Seguro in Bahia, Brazil, between March and May 2019. A priori probability distributions were generated using a Bayesian approach and simulations to assess MP intake based on varying exposure amounts (θ = 0.2, θ = 0.5, and θ = 0.8). E. brasilianus (53.33%) and Mugil spp. (41.66%) were contaminated with some types of MPs. Black, blue, and green MPs dominated in the extracted samples, and most measured 1.0 mm in length or smaller. The dominant polymers identified using Fourier transform infrared spectroscopy (FTIR) were polyester, polypropylene, semi-synthetic rayon fiber, and polyamide 6 (nylon). The a posteriori probabilities of more than half the E. brasilianus and Mugil spp. ingesting MPs were 0.336 and 0.008, respectively, indicating that E. brasilianus is much more likely to ingest MPs. These simulations can be useful tools for assessing the environmental quality and local anthropic impact of MP ingestion by fish populations.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Teorema de Bayes , Brasil , Monitoramento Ambiental , Plásticos , Poluentes Químicos da Água/análise
8.
Chemosphere ; 276: 130161, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088082

RESUMO

The global reliance on pharmaceuticals coupled with the lack of effective treatment methods has resulted in pseudo-persistence of pharmaceuticals within the environment. Globally, efforts to quantify and monitor pharmaceuticals within the environment have been well underway, however few studies have been made within small Pacific Islands. This study aims at screening for the occurrence and concentration of pharmaceutical residues within the southern coastal waters of Fiji's main island, Viti Levu. Water samples were collected from a depth of ca. 0.6 m from seven sites and were analyzed for 80 pharmaceuticals via a combination of chromatography and heated electrospray ionization. Seventy-two pharmaceuticals were quantified at least once with average concentrations ranging between 0.04 ng/L (diltiazem) and 19 ng/L (ketoconazole), and with all but two pharmaceuticals (trimethoprim and biperiden) being present in less than 50% of the samples. Findings suggest that even though the release of pharmaceuticals into the marine environment is sporadic and pharmaceuticals are diluted via turbulent mixing, there are measurable concentrations of pharmaceuticals in Fiji and these pollutants are not necessarily restricted to highly populated areas.


Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Monitoramento Ambiental , Fiji , Pesquisa , Poluentes Químicos da Água/análise
9.
Chemosphere ; 276: 130220, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088098

RESUMO

The increasing discharge of high-salinity organic wastewater has drawn much concern. This work investigated the degradation and mineralization of ciprofloxacin (CIP) in high-salinity wastewater by ozonation coupled with ultraviolet irradiation (UV). After coupling with UV, the removal efficiency of CIP was increased insignificantly (maximum 5.0%), while the dissolved organic carbon (DOC) removal in CIP wastewater (CW) was enhanced dramatically to 91.4% as compared with independent O3 (37.5%). The reactive oxygen species (ROS) were identified as singlet oxygen (1O2) and superoxide anion radical (O2-•)·through electron paramagnetic resonance (EPR) and quenching experiments, among which 1O2 predominated in the UV/O3 process. The existence of salt (Na2SO4 or NaCl) accelerated the mass transfer of O3 at the gas-liquid interface, thus CIP removal was promoted in UV/O3/SO42- system. However, excessive Cl- inhibited the removal efficiency of DOC in CW owing to its consumption of O3. CIP degradation decreased as pH increased in non-salinity and UV/O3/SO42- system, which proved the direct reaction occurred between CIP and O3. On the contrary, the O3 mass transfer increased with increasing pH, hence the elimination of DOC in CW was promoted in UV/O3/Cl- system. Volatile organic compounds (VOCs) were detected from tail gas, but the toxicity estimation indicated the toxicity of products was similar or less than that of CIP. Overall, this work is meaningful for the practical application of UV/O3 process in the high-salinity industry.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Ciprofloxacina , Salinidade , Raios Ultravioleta , Poluentes Químicos da Água/análise
10.
Chemosphere ; 276: 130265, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088106

RESUMO

To ensure safe drinking water sources in the future, it is imperative to understand the quality and pollution level of existing groundwater. The prediction of water quality with high accuracy is the key to control water pollution and the improvement of water management. In this study, a deep learning (DL) based model is proposed for predicting groundwater quality and compared with three other machine learning (ML) models, namely, random forest (RF), eXtreme gradient boosting (XGBoost), and artificial neural network (ANN). A total of 226 groundwater samples are collected from an agriculturally intensive area Arang of Raipur district, Chhattisgarh, India, and various physicochemical parameters are measured to compute entropy weight-based groundwater quality index (EWQI). Prediction performances of models are determined by introducing five error metrics. Results showed that DL model is the best prediction model with the highest accuracy in terms of R2, i.e., R2 = 0996 against the RF (R2 = 0.886), XGBoost (R2 = 0.0.927), and ANN (R2 = 0.917). The uncertainty of the DL model output is cross-verified by running the proposed algorithm with newly randomized dataset for ten times, where minor deviations in the mean value of performance metrics are observed. Moreover, input variable importance computed by prediction models highlights that DL model is the most realistic and accurate approach in the prediction of groundwater quality.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Índia , Aprendizado de Máquina , Poluentes Químicos da Água/análise , Qualidade da Água
11.
Environ Monit Assess ; 193(6): 378, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34075483

RESUMO

This paper presents the comprehensive evaluation of the level of accumulation of some of the most dangerous environmental pollutants (V, Co, Sn, Ni, Cr, Mn, Cd, Cu, Pb, Sb, Zn) and analyses their chemical forms in sediments of four small lakes located within Murmansk urban territory. Furthermore, the authors first studied morphology and chemical composition of industrial dust collected from the snow covering the ice of Lake Srednee. Fieldwork was carried out in April 2019. The results showed that sediments of the Murmansk urban lakes are significantly enriched in the content of the toxic metals and metalloids Cd, Pb, Sb, Zn, Cu, V, and Ni. An integrated assessment of anthropogenic impact using the pollution load index (PLI) and geoaccumulation index (Igeo) revealed a moderate to the extremely strong pollution level in recent sediment layers. The analysis of the fractions of the elements showed that they are mainly associated with stable compounds, such as primary minerals or persistent technogenic compounds (slag, matte, and dust). However, humic substances are a significant accumulative matrix for most studied elements. The share of the most mobile fractions does not exceed 30% for the vast majority of elements, even in the most polluted layers. The accumulation of the major part of pollutants can be attributed to the activities of the main industrial objects of the city (thermal power plant, coal port, transport infrastructure), and the impact of the global atmospheric transport of pollutants to the Arctic regions of Russia.


Assuntos
Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Regiões Árticas , Cidades , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Metais Pesados/análise , Medição de Risco , Federação Russa , Oligoelementos/análise , Poluentes Químicos da Água/análise
12.
Braz J Biol ; 82: e243633, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34076166

RESUMO

Snow trout (Schizothorax plagiostomus) is an economically important freshwater fish, mostly found in northern areas of water reservoirs of Pakistan. The current study was conducted in River Swat to analyze the bioaccumulation of heavy metals (Pb, Cr, Ni, and Zn) in tissues of Schizothorax plagiostomus. Tissues were extracted and dissolved in perchloric acid (HClO4) and nitric acid (HNO3) along with hotplate. The heavy metals, zinc (Zn), lead (Pb), chromium (Cr), and Nickel (Ni) were determined using Perkin Elmer 2380 atomic absorption spectrophotometer. Results shows great variation in the content of the metal related to tissue type and sampling sites. A high concentration of bioaccumulation was reported at Charbagh, whereas lowest at Odigram: Charbagh>Landakai>Odigram. In the same way, Cr was the most accumulated heavy metal followed by lead, nickel, and Zinc.


Assuntos
Cyprinidae , Metais Pesados , Poluentes Químicos da Água , Animais , Bioacumulação , Monitoramento Ambiental , Metais Pesados/análise , Paquistão , Rios , Poluentes Químicos da Água/análise
13.
Water Sci Technol ; 83(11): 2714-2723, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115625

RESUMO

The textile industry is one of the main generators of industrial effluent due to the large volumes of water containing a wide variety of pollutants, including dyes. Thus, the present study aimed to remove the Disperse Blue 56 dye present in synthetic textile effluent using ionic flocculation through surfactant flocs produced from animal/vegetable fat, assessing the system at different surfactant concentrations and temperatures. The process kinetics, adsorption mechanism and equilibrium were evaluated. The results show that the kinetics was better described by the Elovich model when compared to pseudo-first order and pseudo-second order models, indicating that chemical adsorption occurs during the process. The study of the adsorption mechanism obtained lower outer layer diffusivities than their intra-particle counterparts, demonstrating that the dye transport to the surfactant floc is controlled through the outer layer. The Langmuir isotherm was suitable for equilibrium data and the separation factor calculated showed that the isotherm is classified as favorable. Dye removal efficiency reached 87% after 360 minutes of contact between the effluent and the surfactant flocs, indicating that ionic flocculation is an efficient alternative in the treatment of textile effluent containing disperse dye.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Antraquinonas , Corantes , Floculação , Concentração de Íons de Hidrogênio , Cinética , Indústria Têxtil , Têxteis , Poluentes Químicos da Água/análise
14.
Water Sci Technol ; 83(11): 2732-2743, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115627

RESUMO

A novel photocatalytic continuous system has been proposed for the treatment of tannery waste water, which has high levels of environmental pollutants. The purification process was performed by passing wastewater on a titanium dioxide (TiO2)-coated surface, which is continuously activated by irradiation of ultraviolet light. To improve the yield of the process, ferric chloride (FeCl3) was used as a coagulation agent. The organic and inorganic compounds, as well as the microorganisms in the tannery wastewater media, were degraded through a photocatalytic process. The results revealed that total dissolved solids and total suspended solids contents were significantly decreased from 8,450 and 8,990 mg·L-1 to 4,032 and 4,127 mg·L-1, respectively. Furthermore, the chemical oxygen demand content of the sample was reduced from 370 to 50 mg·L-1 after the addition of 100 mL of FeCl3 and 4 h of treatment. The same results were observed for the elimination of sulfate and chromium ions, which led to a decline in electrical conductivity. This suggests that introducing 100 mL of FeCl3 as the coagulation agent and continuous treatment with photocatalityc set-up could be considered as an effective method for the purification of tannery wastewaters.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Catálise , Titânio , Águas Residuárias , Poluentes Químicos da Água/análise
15.
Water Sci Technol ; 83(11): 2793-2808, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115632

RESUMO

In this work, mixed oxides of LaxCa1-xMnO3 perovskite type (x = 0, 0.5 and 1.0) were synthesized through modified proteic method using collagen and calcination process at 700 °C/2 h in order to remove the commercial textile dye Bezaktiv Blue S-MAX from water. Oxides were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 physisorption, scanning electron microscopy (SEM) and point of zero charge (PZC) techniques while the dye only by the first two techniques. The XRD showed that perovskite monophase was obtained for x = 0.5 and 1.0. However, for x = 0, the low crystalline perovskite phase was obtained in the midst of precursor oxides. FTIR showed the adsorption process did not damage the adsorbents structure. The successful obtained materials have meso and macroporous with slit or cavity shape, rough surface and particles with varying sizes. The pseudo-second-order model was the one that best fit the kinetic data. The process must occur through electrostatic surface interactions between the adsorbent surface and the dye molecule. For the equilibrium study, Langmuir isotherm is the most suitable when using LaMnO3 adsorbent, while Freundlich isotherm was better suited when used the other two materials. The adsorbents were termally regenerated and reused five times. The best performance was exhibited by LaMnO3.


Assuntos
Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Poluentes Químicos da Água/análise
16.
Water Sci Technol ; 83(11): 2809-2828, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115633

RESUMO

The horizontal subsurface flow constructed wetland (HFCW) is widely studied for the treatment of wastewater containing emerging organic contaminants (EOCs): pharmaceuticals, personal care products, and steroidal hormones. This study evaluates the performance of HFCW for the removal of these types of EOCs based on the data collected from peer-reviewed journal publications. In HFCW, anaerobic biodegradation is an important removal mechanism of EOCs besides their removal by the filter media (through sedimentation, adsorption, and precipitation) and plant uptake. The average removal efficiency of 18 selected EOCs ranged from 39% to 98%. The moderate to higher removal efficiency of 12 out of 18 selected EOCs in HFCW indicates the suitability of this type of constructed wetland (CW) for the treatment of wastewater containing these EOCs. The reasonably good removal (>50% in most of the cases) of these EOCs in HFCW might be due to the occurrence of anaerobic biodegradation as one of their major removal mechanisms in CWs. Although the effluent concentration of EOCs was substantially decreased after the treatment, the environmental risk posed by them was not fully reduced in most of the cases. For instance, estimated risk quotient of 11 out of 18 examined EOCs was extremely high for the effluent of HFCW.


Assuntos
Poluentes Químicos da Água , Áreas Alagadas , Anaerobiose , Biodegradação Ambiental , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Poluentes Químicos da Água/análise
17.
Water Sci Technol ; 83(11): 2829-2840, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115634

RESUMO

First flush is a common phenomenon in urban runoff pollution. Typical cement roof and asphalt road runoff in Beijing, China were monitored for 2 years. Based on the M(v) curve, the suspended solids (SS), chemical oxygen demand (COD), total phosphorus (TP) and particulate phosphorus in cement roof runoff presented a stronger first flush than those in asphalt road runoff. The first flush volume (VFF) of SS, COD, total nitrogen (TN) and TP in asphalt road runoff differed slightly from the cement roof. There were also differences in the first flush assessment depending on which method was used. We proposed a new method based on the runoff depth versus pollutant cumulative mass curve. According to the national standards in China (VFF = 3 mm), various masses of different pollutants, such as 91.42 ± 9.80% (cement roof) and 78.49 ± 19.41% (asphalt road) of SS and 86.85 ± 13.54% (cement roof) and 72.80 ± 25.79% (asphalt road) of COD, can be effectively controlled, but our mass control efficiencies were 55.91%-66.65% when VFF = 1 mm. The new method proposed in this study provides an alternative approach for assessing runoff pollution control efficiency of different VFF.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Pequim , China , Cidades , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise , Chuva , Movimentos da Água , Poluentes Químicos da Água/análise
18.
Arch Environ Contam Toxicol ; 81(1): 58-66, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34014341

RESUMO

Heavy metals are continuously released into the oceans from both natural and anthropogenic sources. They are serious threats to both ecosystem and human health because of their toxicity, persistence, bioaccumulation, and biomagnification. We present metal concentrations in the economically important bluefish from Iskenderun Bay, providing valuable information on Northeastern Mediterranean aquatic ecosystem health, as well as the human health risk. The concentrations of manganese, iron, copper, zinc, selenium, cadmium, lead, and mercury were determined in the gill, liver, and muscle tissues of bluefish (Pomatomus saltatrix) caught in Iskenderun Bay (Turkey) during four seasons. Samples were analysed via inductively coupled plasma mass spectrometer. Fe and Zn were detected in the highest concentrations during all four seasons. The ranges of Fe concentrations were 61.15-108.76, 229.78-377.02, and 6.35-8.63 and those of Zn were 25.21-44.25, 42.25-76.08, and 6.27-13.59 in the gills, livers, and muscles, respectively. In contrast, Hg and Cd were not found in the bluefish tissues in any season with the exception of Cd in the gills during the spring (0.757 mg/kg, above the legal limit of 0.5 mg/kg). On a seasonal basis, no meaningful accumulation trend was observed for the muscles or gills, while the highest concentrations of Mn, Fe, Cu, Zn, and Se in the liver were found in the spring. Liver tissues possessed higher metal concentrations than gill and muscle tissues. Estimated daily and weekly intakes of the metals due to human consumption of the bluefish were considerably lower than the provisional tolerable intake. In this study, there was an inflow of metals into Iskenderun Bay; however, no significant metal accumulation was found in bluefish tissues at a rate that would harm human health.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Animais , Bioacumulação , Ecossistema , Monitoramento Ambiental , Brânquias/metabolismo , Humanos , Fígado/química , Metais Pesados/análise , Músculos/química , Medição de Risco , Estações do Ano , Turquia , Poluentes Químicos da Água/análise
19.
Arch Environ Contam Toxicol ; 81(1): 25-35, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34027570

RESUMO

Dragonflies (Order Odonata) often are considered to be biosentinels of environmental contamination, e.g., heavy metals and/or persistent organic pollutants (POPs). Dragonflies (n = 439) belonging to 15 species of 8 genera were collected from an abandoned mercury (Hg) mining region in China to investigate the bioaccumulation of total Hg (THg) and methylmercury (MeHg). THg and MeHg concentrations in dragonflies varied widely within ranges of 0.06-19 mg/kg (average: 1.5 ± 2.2 mg/kg) and 0.02-5.7 mg/kg (average: 0.75 ± 0.65 mg/kg), respectively. THg and MeHg were positively correlated with bodyweight (THg: r2 = 0.10, P = 0.000; MeHg: r2 = 0.09, P = 0.000). Significant variations were observed among species, with the highest MeHg value (in Orthetrum triangulare) was fivefold higher than the lowest (in Pantala flavescens). These variations were consistent with those of nitrogen isotope (δ15N) values, indicating that increased δ15N, i.e., trophic levels, may reflect increased exposure and uptake of biomagnifying MeHg in dragonflies. A toxicological risk assessment found hazard quotients for specialist dragonfly-consuming birds of up to 7.2, which is 2.4 times greater than the permissible limit of 3, suggesting a potential toxicological risk of exposure.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Odonatos , Poluentes Químicos da Água , Animais , China , Monitoramento Ambiental , Cadeia Alimentar , Mercúrio/análise , Mineração , Poluentes Químicos da Água/análise
20.
J Chromatogr A ; 1649: 462188, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34034108

RESUMO

A new green method for trace level quantification of four herbicides, glyphosate (GLYP), glufosinate (GLUF), and their main metabolites, aminomethylphosphonic acid (AMPA) and 3-(methyl-phosphinico)-propionic acid (MPPA), was developed. The purification step without any derivatization was conducted by solid-phase extraction using Chelex-100 resin in the Fe (III) form, followed by elution with 5% NH4OH. The four analytes were quantified by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. The developed extraction method was validated on five fresh and sea water matrices with mean recoveries ranging from 80.1% to 109.4% (relative standard deviation < 20%). The extraction conditions were evaluated and certified for the high applicability of the extraction method too. The limits of detection (ng/L) in the five water matrices were in ranges 0.70 - 4.0, 2.4 - 3.9, 1.8 - 4.7, and 1.6 - 4.0 for GLYP, AMPA, GLUF, and MPPA, respectively. The method was successfully applied to detect the four compounds in surface waters sampled along the Red River Delta region in July 2019. The highest concentrations were detected at 565, 1,330, 234, and 871 ng/L for GLYP, AMPA, GLUF, and MPPA, respectively. These results showed the potential capacity of this new method for convenient monitoring of herbicides and their metabolites in the diverse natural water system.


Assuntos
Aminobutiratos/isolamento & purificação , Glicina/análogos & derivados , Organofosfonatos/isolamento & purificação , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/isolamento & purificação , Aminobutiratos/análise , Cromatografia Líquida de Alta Pressão , Água Doce/química , Glicina/análise , Glicina/isolamento & purificação , Herbicidas/análise , Herbicidas/isolamento & purificação , Organofosfonatos/análise , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
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