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1.
Sci Total Environ ; 793: 148630, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34328994

RESUMO

For the first time, background threshold values have been developed for a large suite of sediment quality parameters from 969 lakes spanning the conterminous United States (U.S.). These values provide a statistical basis for estimating current ambient background, which refers to chemical and physical (e.g., grain size) concentrations derived from natural and/or widespread diffuse anthropogenic sources (e.g., nonpoint sources like atmospheric deposition and land runoff). Surficial sediment quality data, collected based on the randomized, probability-based sampling design of the 2017 National Lakes Assessment (NLA) study, were utilized for this effort. These data included 16 metal(loid)s, 25 polycyclic aromatic hydrocarbons (PAHs), 53 polychlorinated biphenyl (PCB) congeners, 27 legacy organochlorine pesticides and metabolites, total organic carbon (TOC), and grain size parameters. The data were analyzed based on different geographic areas, including: 10 U.S. Environmental Protection Agency (EPA) Regions, two major ecoregions bisecting the State of Minnesota (i.e., Temperate Plains and Upper Midwest), and for Minnesota. Hypothesis testing of 47 sediment quality parameters was performed on three geographic areas bisecting Minnesota, and there were many statistically significant (p < 0.05) differences between geographic pairs that included Minnesota. Background threshold values were calculated for parameters with >20% detects using 95% one-sided upper tolerance limit (UTL) with 95% coverage (UTL95-95) values. The UTL95-95 represents the value below which 95% of the population values are expected to fall with 95% confidence. These values were compared to matching sediment quality guidelines for the protection of benthic organisms, both with and without potential outliers removed. Applications and limitations of the UTL95-95 values are discussed. Jurisdictions within the continental U.S. could use these same publicly available sediment quality data to calculate UTL95-95 values for specific geographic areas, and other countries could design similar probabilistic field studies to determine current ambient background of sediment quality parameters in lake sediments.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Lagos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Estados Unidos , Poluentes Químicos da Água/análise
2.
Huan Jing Ke Xue ; 42(8): 3743-3752, 2021 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-34309260

RESUMO

The sources and spatial variations of dissolved organic matter (DOM) in summer water of inflow rivers (FL, HB, QY, ZH, and NF) along the Chaohu Lake watershed were analyzed using the ultraviolet-visible absorption spectrum (UV-vis) method and three-dimensional excitation emission matrix fluorescence spectroscopy-parallel factor analysis (EEM-PARAFAC). The specific ultraviolet absorbance of DOM at 254 nm in the NF river was lower than in other rivers, and the spectral slope ratio (SR) of the NF river was higher than that of the HB river. This showed that the urban runoff inputs reduce the aromaticity of DOM in the NF river water, but has little effect on the molecular weight. The high fluorescence index (FI) and biological index, and the low humification index, indicated the main autochthonous sources of the DOM in the NF river. Four humic-like components (C1-C4), comprising terrestrial organic matter (C1, C3, and C4) and microbial degradation products (C2), and two protein-like components (C5 and C6) were identified as the main sources of DOM in the inflow rivers along the Chaohu Lake watershed. The dissolved organic carbon and DOM fluorescence components in the river water exhibited spatial variation along the direction of flow. The DOM in water from FL, HB, QY, and ZH was sourced from soil runoff inputs, whereas in NF water, it was mainly sourced from urban runoff and wastewater treatment plant effluents.


Assuntos
Lagos , Rios , Lagos/análise , Estações do Ano , Espectrometria de Fluorescência , Água , Qualidade da Água
3.
Artigo em Inglês | MEDLINE | ID: mdl-34283016

RESUMO

Two halophilic archaeal strains, Gai3-2T and NJ-3-1T, were isolated from salt lake and saline soil samples, respectively, collected in PR China. The 16S rRNA gene sequences of the two strains were 97.5% similar to each other. Strains Gai3-2T and NJ-3-1T had the highest sequence similarities to 'Halobonum tyrrellense' G22 (96.7 and 97.8%, respectively), and displayed similarities of 91.5-93.5% and 92.3-94.7%, respectively, to Halobaculum members. Phylogenetic analysis revealed that the two strains formed different branches and clustered tightly with 'H. tyrrellense' G22 and Halobaculum members. The average nucleotide identity (ANI), in silico DNA-DNA hybridization (isDDH) and amino acid identity (AAI) values between the two strains were 83.1, 26.9 and 77.9%, respectively, much lower than the threshold values proposed as a species boundary. These values between the two strains and 'H. tyrrellense' G22 (ANI 77.9-78.2%, isDDH 22.5-22.6% and AAI 68.8-69.3%) and Halobaculum members (ANI 77.53-77.63%, isDDH 21.8-22.3% and AAI 68.4-69.4%) were almost identical, and much lower than the recommended threshold values for species delimitation. These results suggested that strains Gai3-2T and NJ-3-1T represent two novel species of Halobaculum. Based on phenotypic, chemotaxonomic and phylogenetic properties, strains Gai3-2T (=CGMCC 1.16080T=JCM 33550T) and NJ-3-1T (=CGMCC 1.16040T=JCM 33552T) represent two novel species of the genus Halobaculum, for which the name Halobaculum halophilum sp. nov. and Halobaculum salinum sp. nov. are proposed.


Assuntos
DNA Arqueal/isolamento & purificação , Halobacteriaceae/isolamento & purificação , Lagos/análise , Extratos Vegetais/isolamento & purificação , Solo/química , DNA Arqueal/genética , Halobacteriaceae/genética , Filogenia , Extratos Vegetais/genética , Análise de Sequência de DNA/métodos
4.
Environ Monit Assess ; 193(8): 536, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34328576

RESUMO

Meteorological features influence the dynamics of aquatic ecosystems and consequently their biotas. This study aimed to identify the meteorological drivers of phytoplankton biomass (chlorophyll a), sampled seasonally over a period of 12 years (2001-2013) in Lake Mangueira, a large shallow subtropical lake in southern Brazil. The lake is 90 km long and 3-10 km wide with a mean depth of 3 m and is oligo-mesotrophic and highly affected by wind action. In general, non-parametric multiplicative regression analysis identified wind direction, radiation, and the Oceanic Niño Index as the main drivers of variation in chlorophyll a. Notably, ENSO periods caused changes in physical, chemical, and meteorological parameters, including conductivity, total suspended solids, total and dissolved nitrogen, alkalinity, soluble reactive silica, wind speed, and precipitation. Phytoplankton biomass showed significant differences between ENSO periods and the periods without events, occurring in the highest values during La Niña years. This study showed that meteorological variables can significantly influence productivity patterns, indicating the importance of including them in limnological studies.


Assuntos
Lagos , Fitoplâncton , Biomassa , Brasil , Clorofila A , Ecossistema , Monitoramento Ambiental , Lagos/análise , Estações do Ano
5.
Huan Jing Ke Xue ; 42(7): 3166-3175, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212642

RESUMO

Microplastics have been found in many environmental media such as sea water, coastal tidal flats, terrestrial water, sediments, and organisms. Microplastics pollution in inland freshwater lakes have received extensive attention; however, the correlation between eutrophication and microplastics pollution in freshwater lakes remains unclear. In this study, 24 sampling sites were set up in the near shore surface waters of Dianchi Lake, and the pollution characteristics of microplastics such as abundance, composition, particle size, color, and form were evaluated. Water quality parameters related to eutrophication state were analyzed, and the eutrophication indices were further calculated. Specifically, sample pre-treatment was conducted according to the method issued by National Oceanic and Atmospheric Administration (NOAA) of the United States. The color and morphological characteristics of microplastic samples were observed using a stereoscopic microscope, and counts and particle size measurements were performed using Nano Measure 1.2 software. Parts of the samples were selected, and the polymer composition analysis was performed using micro-Fourier Transform infrared (µ-FTIR) spectroscopy. The indices related to eutrophication level evaluation were tested according to the experimental standard methods issued by the Ministry of Ecology and Environment of China. The results showed that the abundance of microplastics in the near shore waters of Dianchi Lake was between 800 and 6000 n·m-3, with an average value of 2867 n·m-3. The types of polymers detected were polyethylene terephthalate (PET), polyetherurethane (PEU), polypropylene (PP), polyethylene (PE), and polyvinyl acetate (PVAc), respectively. The diameter proportion of microplastics in the range of 0.2-0.5 mm was the highest. Fiber microplastics accounted for the most observed type, followed by fragments and films. Among the 24 monitoring sites, it was found that proportions of severe, moderate, and mild eutrophication and mesotrophication sites accounted for 8.33%, 58.33%, 29.17%, and 4.17% of the total sampling sites, respectively, and the main pollutant was total nitrogen (TN). Microplastics abundances in the near shore waters of Dianchi Lake were significantly positively correlated with TN concentrations (P<0.01), whereas they were negatively correlated with chlorophyll a(Chl-a)concentrations, not reaching a significant level (P>0.05). The microplastics abundance and TN concentrations in the north bank water near the main urban area of Kunming were significantly higher than those in the other three banks. Microplastics and TN were considered to potentially have the same origin and be attributed to the tail water discharge from WWTPs.


Assuntos
Microplásticos , Poluentes Químicos da Água , China , Clorofila A , Monitoramento Ambiental , Eutrofização , Sedimentos Geológicos , Lagos/análise , Plásticos , Poluentes Químicos da Água/análise
6.
ACS Appl Mater Interfaces ; 13(24): 28610-28626, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34110776

RESUMO

The development of aggregation-induced emission enhancement (AIEE) active nanoprobes without any synthetic complication for solution-state and organic thin-film transistor (OTFT)-based sensory applications is still a challenging task. In this study, the novel pyrene-incorporated Schiff base (5-phenyl-4-((pyren-1-ylmethylene)amino)-4H-1,2,4-triazole-3-thiol; PT2) with an AIEE property was synthesized via a one-pot reaction and was reported for detecting Zn2+ and tyrosine in the solution state and OTFT. In the AIEE studies of PT2 (in CH3CN) at various water fractions (fw: 0-97.5%), the existence of J-aggregation, crystalline changes, and nanofibers formation was confirmed by ultraviolet absorption/photoluminescence (UV/PL) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic-light scattering (DLS) techniques. Similarly, PT2-based Zn2+ detection and sensory reversibility with tyrosine were demonstrated by UV/PL studies with evidence related to crystalline/nanolevel changes in PXRD, SEM, TEM, AFM, and DLS data. Distinct decay profiles associated with the AIEE and sensory responses of PT2 were observed in time-resolved photoluminescence spectra. From the standard deviation and linear fittings of PL titrations, detection limits (LODs) of the Zn2+ with PT2 and the tyrosine with PT2-Zn2+ were estimated as 0.79 and 45 nM, respectively. High-resolution mass and 1H NMR results confirmed 2:1 and 1:1 stoichiometry and binding sites of PT2-Zn2+-PT2* and tyrosine-Zn2+ complexes. Moreover, the values of association constants determined by linear fittings were 4.205 × 10-7 and 1.73 × 10-8 M-2, correspondingly. Optimization via the density functional theory disclosed the binding sites and suppression of twisted intramolecular charge transfer/photoinduced electron transfer (TICT/PET) as well as the involvement of restricted intramolecular rotation in the AIEE and PET "ON-OFF-ON" mechanisms in the Zn2+ and tyrosine sensors. Results from the B16-F10 cellular and zebrafish imaging of AIEE, Zn2+, and tyrosine sensors further attested the applicability of PT2 in biological samples. Finally, the PT2 and pentacene-incorporated OTFT devices were fabricated. The devices displayed more than 90% change in drain-source current when reacted with Zn2+ with an LOD of 5.46 µM but showed no response to tyrosine, thereby confirming the reversibility. Moreover, the OTFT devices also demonstrated Zn2+ ion detection in tap water and lake water samples.


Assuntos
Corantes Fluorescentes/química , Pirenos/química , Tirosina/análise , Zinco/análise , Animais , Teoria da Densidade Funcional , Água Potável/análise , Técnicas Eletroquímicas/métodos , Corantes Fluorescentes/síntese química , Lagos/análise , Limite de Detecção , Modelos Químicos , Pirenos/síntese química , Bases de Schiff/síntese química , Bases de Schiff/química , Transistores Eletrônicos , Peixe-Zebra
7.
Water Res ; 201: 117363, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34174729

RESUMO

Eutrophic lakes, especially shallow eutrophic lakes, disproportionately contribute to greenhouse gas (GHG) emissions. To investigate the effects of eutrophication on GHG dynamics, we conducted field measurements every three months from January 2019 to October 2019 in Lake Ulansuhai, a shallow eutrophic lake (mean depth of 0.7 m) located in a semi-arid region in Northern China. We found that Lake Ulansuhai was a predominantly source of atmospheric carbon dioxide (CO2); however, it converted to a CO2 sink in July due to eutrophication. It was also a strong source of methane (CH4) with a mean CO2 emission of 35.7 ± 12.1 mmol m-2 d-1 and CH4 emission of 5.9 ± 2.9 mmol m-2 d-1. The CO2 concentrations in most sites and CH4 concentrations in all sites were supersaturated, with the average partial pressure of CO2 (pCO2) being 654±34 µatm and the partial pressure of CH4 (pCH4) being 157±37 µatm. The partial pressures and emissions of the greenhouse gases exhibited substantial seasonal and spatial variations. The correlation analysis between the trophic level index and the partial pressure of the greenhouse gases indicated that eutrophication could significantly decrease the CO2 emissions but increase the CH4 emissions from the lake, resulting in a CH4 and CO2 emission ratio of approximately 2 in terms of global warming potential. Eutrophication decreased the pCO2 in the lake and subsequently increased the pCH4 due to nutrient input, thereby enhancing primary production. The results indicated that shallow eutrophic lakes in arid regions are strong sources of CH4 and that eutrophication could alter the greenhouse gas emission patterns.


Assuntos
Gases de Efeito Estufa , Lagos , Dióxido de Carbono/análise , China , Eutrofização , Lagos/análise , Metano/análise
8.
Environ Pollut ; 286: 117286, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33990046

RESUMO

The Peace-Athabasca Delta (PAD) receives a mixture of hydrocarbons from biogenic, pyrogenic, and petrogenic processes. Source apportionment in the PAD has focussed on polycyclic aromatic compounds (PACs), which are ubiquitous in the environment and susceptible to weathering. In contrast, petroleum biomarkers of terpanes, hopanes, and steranes are degradation-resistant organic compounds found uniquely in petroleum products that can identify the input and origin of petrogenic hydrocarbons (PHCs). We provide an analysis of environmentally-relevant PHCs (including n-alkanes, PACs, and petroleum biomarkers) in surficial sediments of strategically selected lakes in the Athabasca and Peace deltas and adjacent boreal uplands. Alkanes were found to be predominately biogenic in all lakes. PAC sources were identified as wood combustion in the upland boreal lakes, a mixture of petrogenic and pyrogenic combustion in two closed-drainage lakes in the Peace Delta, and predominately petrogenic in two flood-prone Athabasca Delta lakes. Using multivariate analyses, raw Alberta oil sands were identified as a potential source of PHCs to the two flood-prone lakes in the Athabasca Delta. Biomarkers of terpanes and hopanes were identified in the Peace Delta and boreal uplands, likely from bitumen and transported atmospherically. These findings validate the use of petroleum biomarkers as tracers for bituminous sands in surficial lake sediments and their potential use in paleolimnological investigations at the PAD to improve understanding of relative roles of natural and industrial processes on far-field deposition of PHCs.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Alberta , Biomarcadores , Monitoramento Ambiental , Hidrocarbonetos/análise , Lagos/análise , Campos de Petróleo e Gás , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise
9.
Water Res ; 196: 116985, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33735621

RESUMO

Lakes are important sources of greenhouse gases (GHGs) to the atmosphere. Factors controlling CO2, CH4 and N2O fluxes include eutrophication and warming, but the integrated influence of climate-warming-driven stratification, oxygen loss and resultant changes in bloom characteristics on GHGs are not well understood. Here we assessed the influence of contrasting meteorological conditions on stratification and phytoplankton bloom composition in a eutrophic lake, and tested for associated changes in GHGs inventories in both the shallow and deep waters, over three seasons (2010-2012). Atmospheric heatwaves had one of the most dramatic effects on GHGs. Indeed, cyanobacterial blooms that developed in response to heatwave events in 2012 enhanced both sedimentary CH4 concentrations (reaching up to 1mM) and emissions to the atmosphere (up to 8 mmol m-2 d-1). That summer, CH4 contributed 52% of the integrated warming potential of GHGs produced in the lake (in CO2 equivalents) as compared to between 34 and 39% in years without cyanobacterial blooms. High CH4 accumulation and subsequent emission in 2012 were preceded by CO2 and N2O consumption and under-saturation at the lake surface (uptakes at -30 mmol m-2 d-1 and -1.6 µmol m-2 d-1, respectively). Fall overturn presented a large efflux of N2O and CH4, particularly from the littoral zone after the cyanobacterial bloom. We provide evidence that, despite cooling observed at depth during hot summers, CH4 emissions increased via stronger stratification and surface warming, resulting in enhanced cyanobacterial biomass deposition and intensified bottom water anoxia. Our results, supported by recent literature reports, suggests a novel interplay between climate change effects on lake hydrodynamics that impacts both bloom characteristics and GHGs production in shallow eutrophic lakes. Given global trends of warming and enrichment, these interactive effects should be considered to more accurately predict the future global role of lakes in GHG emissions.


Assuntos
Gases de Efeito Estufa , Lagos , Dióxido de Carbono/análise , China , Lagos/análise , Metano/análise , Fitoplâncton
10.
Huan Jing Ke Xue ; 42(3): 1354-1360, 2021 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-33742932

RESUMO

Phenol is widely used in the production of insulation and thermal insulation materials, adhesives, perfumes, coatings for food containers, paints, and pharmaceutical production, and is also widely detected in the aquatic environment. Long-term exposure to phenol can elicit adverse effects, such as skin burn, liver and central system damage. Here, phenol concentrations in the water and aquatic products of Poyang Lake were investigated. Human health risks from phenol to adults and adolescents were also assessed based on local population exposure parameters. The exposure concentration range of phenol in the studied water and aquatic products was not detected (ND)-556.26 ng·L-1 and 11.98-255.51 µg·kg-1, respectively. Human health risk based on drinking water in different areas ranged from 3.80×10-7-8.46×10-5. Higher human health risks from drinking water was detected in the southern area of Poyang Lake and at the confluence of the Yangtze River to the north. Health risks caused by different types of aquatic products ranges 2.65×10-5-1.47×10-4. In particular, human health risks from the consumption of yellow catfish and catfish are an order of magnitude higher than for other aquatic products. Probabilistic risk assessment was also conducted through Monte Carlo simulation to analyze the health risk to the population in the Poyang Lake Basin and assess its sensitivity of different exposure parameters. The 95th percentile health risk of drinking water and aquatic product consumption in the Poyang Lake Basin was calculated as being acceptable. Overall, the concentrations of phenol had the greatest impact on the calculated health risk values. This study provides valuable information for phenol risk management in the Poyang Lake basin.


Assuntos
Lagos , Fenol , Adolescente , China , Monitoramento Ambiental , Humanos , Lagos/análise , Medição de Risco , Rios , Água
11.
Water Res ; 196: 117053, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33774349

RESUMO

Understanding the climatic drivers of eutrophication is critical for lake management under the prism of the global change. Yet the complex interplay between climatic variables and lake processes makes prediction of phytoplankton biomass a rather difficult task. Quantifying the relative influence of climate-related variables on the regulation of phytoplankton biomass requires modelling approaches that use extensive field measurements paired with accurate meteorological observations. In this study we used climate and lake related variables obtained from the ERA5-Land reanalysis dataset combined with a large dataset of in-situ measurements of chlorophyll-a and phytoplankton biomass from 50 water bodies to develop models of phytoplankton related responses as functions of the climate reanalysis data. We used chlorophyll-a and phytoplankton biomass as response metrics of phytoplankton growth and we employed two different modelling techniques, boosted regression trees (BRT) and generalized additive models for location scale and shape (GAMLSS). According to our results, the fitted models had a relatively high explanatory power and predictive performance. Boosted regression trees had a high pseudo R2 with the type of the lake, the total layer temperature, and the mix-layer depth being the three predictors with the higher relative influence. The best GAMLSS model retained mix-layer depth, mix-layer temperature, total layer temperature, total runoff and 10-m wind speed as significant predictors (p<0.001). Regarding the phytoplankton biomass both modelling approaches had less explanatory power than those for chlorophyll-a. Concerning the predictive performance of the models both the BRT and GAMLSS models for chlorophyll-a outperformed those for phytoplankton biomass. Overall, we consider these findings promising for future limnological studies as they bring forth new perspectives in modelling ecosystem responses to a wide range of climate and lake variables. As a concluding remark, climate reanalysis can be an extremely useful asset for lake research and management.


Assuntos
Lagos , Fitoplâncton , Biomassa , Clorofila , Clorofila A , Ecossistema , Eutrofização , Lagos/análise
12.
Sci Total Environ ; 771: 144811, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33545474

RESUMO

Due to the difference of vertical distribution of algae in lakes, it is necessary to carry out remote sensing estimation of algal biomass based on the vertically heterogeneous distribution of chlorophyll in order to improve the accuracy of biomass inversion. A new algorithm is proposed and validated to measure algal biomass in Lake Chaohu based on the Moderate Resolution Imaging Spectrometer (MODIS) images. The algal biomass index (ABI) is defined as the difference in remote-sensing reflectance (Rrs, sr-1) at 555 nm normalized against two baselines with one formed linearly between Rrs(859) and Rrs(469) and another formed linearly between Rrs(645) and Rrs(469). Both theory and model simulations show that ABI has a good relation with the algal biomass in the euphotic zone (R2 = 0.88, p < 0.01, N = 50). Field data were further used to estimate the biomass outside the euphotic layer through an empirical algorithm. The ABI algorithm was applied to MODIS Rayleigh-corrected reflectance (Rrc) data after testing the sensitivity to sun glint and thickness of aerosols, which showed an acceptable precision (root mean square error < 21.31 mg and mean relative error < 16.08%). Spectral analyses showed that ABI algorithm was immune to concentration of colored dissolved organic matter (CDOM) but relatively sensitive to suspended particulate inorganic matter (SPIM), which can be solved by using Turbid Water Index (TWI) though in such a challenging environment. A long-term (2012-2017) estimation of algal biomass was further calculated based on the robust algorithm, which shows both seasonal and spatial variations in Lake Chaohu. Tests of ABI algorithm on Sentinel-3 OLCI demonstrates the potential for application in other remote sensors, which meets the need of observation using multi-sensor remote sensing in the future.


Assuntos
Clorofila , Lagos , Biomassa , China , Clorofila/análise , Monitoramento Ambiental , Lagos/análise , Tecnologia de Sensoriamento Remoto
13.
Environ Pollut ; 276: 116739, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33611199

RESUMO

The properties of phosphate in lakes and their ability to cause eutrophication have been well studied; however, the effects of phosphate on the environmental behavior of other substances in lakes have been ignored. Dissolved organic matter (DOM) and heavy metals may coexist with phosphate in lakes. Herein, the mechanisms underlying the influence of phosphate on heavy metals complexation with DOM were investigated using multi-spectroscopic tools. Overall, the amount of DOM-bound Cu(Ⅱ) decreased with the increasing phosphate content. Furthermore, the fluorescence excitation and emission matrix results combined with parallel factor analysis showed that when the Cu(Ⅱ) concentration increased from 0 to 5 mg/L and 50 µM phosphate to the reaction of DOM and copper, the fluorescence intensity of tyrosine (component 1), humic-like (component 2) and tryptophan (component 3) decreased by 36.46%, 57.34%, and 74.70% compared with the treatment with no phosphate addition, respectively. This finding indicates that the binding of different fluorescent components to Cu(Ⅱ) was restricted by phosphate. Furthermore, different functional groups responded differently to Cu(Ⅱ) under different phosphate concentrations. The binding sequence of different functional groups under high concentration of phosphate (phenolic hydroxyl group>amide (Ⅰ) >carbohydrates) was completely opposite to that with no phosphate. These results demonstrated that phosphate could restrict the binding affinity of heavy metals with different fluorescent substances or organic ligands of DOM, suggesting that the comigration of DOM-bound heavy metals in lakes is hindered by phosphate and the risk of heavy metal poisoning in aquatic organisms is therefore diminished.


Assuntos
Cobre , Lagos , Substâncias Húmicas/análise , Lagos/análise , Fosfatos , Espectrometria de Fluorescência
14.
Environ Sci Pollut Res Int ; 28(1): 574-586, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32820436

RESUMO

Seasonal and regional distributions of 17 polycyclic aromatic hydrocarbons (PAHs) in surface waters from four different main water functional regions of the Baiyangdian Lake were analyzed through GC/MS/MS during spring and summer season. The aim was to identify their possible pollution sources and evaluate their health risk for human and ecotoxicological risk for aquatic organisms. Results showed that the range of total PAH concentration is 35.38-88.06 ng/L (average 46.57 ng/L) in spring and 25.64-301.41 ng/L (average 76.23 ng/L) in summer. PAH contamination was observed slightly lower in the summer season from the pollution characteristics of water bodies in most areas of the Baiyangdian Lake, and the levels of PAH pollution in the water body of urban residential regions and rural residential regions were relatively higher than those in tourist regions and low human disturbance regions. Source analysis based on diagnostic ratios confirmed that combustion sources and petroleum sources were two main sources for PAHs entering into the waters of the Baiyangdian Lake. Human health risk assessment showed that PAHs in surface waters from the Baiyangdian Lake will not cause a potential non-carcinogenic risk to local residents and the carcinogenic risk could mostly be accepted, but the potential lifetime carcinogenic risk for infants in rural residential regions should be concerned about. Urban residential regions and rural residential regions were subject to higher cumulative non-carcinogenic and carcinogenic risk when compared to the other functional regions. Ecotoxicological risk assessment found a moderate risk to aquatic organisms presented by individual PAH and a low risk by total PAHs, and PAHs in the water body of urban residential regions and rural residential regions also have relatively higher harm effects to aquatic organisms compared with the other two functional regions. This study revealed the pollution characteristics of PAHs and their possible sources in waters of the Baiyangdian Lake, clarified its correlation to regional anthropogenic activities, and provided corresponding risk management strategies for human and aquatic organisms.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Organismos Aquáticos , China , Monitoramento Ambiental , Humanos , Lagos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
15.
Environ Sci Pollut Res Int ; 28(5): 5383-5397, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32964383

RESUMO

Since 2000, after the Water Framework Directive came into force, aquatic ecosystems' bioassessment has acquired immense practical importance for water management. Currently, due to extensive scientific research and monitoring, we have gathered comprehensive hydrobiological databases. The amount of available data increases with each subsequent year of monitoring, and the efficient analysis of these data requires the use of proper mathematical tools. Our study challenges the comparison of the modelling potential between four indices for the ecological status assessment of lakes based on three groups of aquatic organisms, i.e. phytoplankton, phytobenthos and macrophytes. One of the deep learning techniques, artificial neural networks, has been used to predict values of four biological indices based on the limited set of the physicochemical parameters of water. All analyses were conducted separately for lakes with various stratification regimes as they function differently. The best modelling quality in terms of high values of coefficients of determination and low values of the normalised root mean square error was obtained for chlorophyll a followed by phytoplankton multimetric. A lower degree of fit was obtained in the networks for macrophyte index, and the poorest model quality was obtained for phytobenthos index. For all indices, modelling quality for non-stratified lakes was higher than this for stratified lakes, giving a higher percentage of variance explained by the networks and lower values of errors. Sensitivity analysis showed that among physicochemical parameters, water transparency (Secchi disk reading) exhibits the strongest relationship with the ecological status of lakes derived by phytoplankton and macrophytes. At the same time, all input variables indicated a negligible impact on phytobenthos index. In this way, different explanations of the relationship between biological and trophic variables were revealed.


Assuntos
Aprendizado Profundo , Lagos , Clorofila A , Ecossistema , Monitoramento Ambiental , Lagos/análise , Fitoplâncton , Polônia
16.
Bull Environ Contam Toxicol ; 106(1): 190-197, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32303814

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) pose great risks to lake ecosystem and human health. Comprehensive knowledge on PAHs in lakes is critical for their risk control. 118 samples were collected from different environmental medium to study the occurrence and fluxes of 16 PAH in Lake Taihu. The average ∑PAH16 in air, water, phytoplankton, zooplankton, suspended particle matter, and surface sediments were 122 ng m-3, 61.3 ng L-1, 6500 ng g-1, 4940 ng g-1, 27,900 ng g-1, and 522 ng g-1, respectively. Sediments were contaminated by PAHs from pyrogenic sources. The average fluxes of air-water, dry deposition, and sinking of the 16 individual PAHs were 2900, 300, and 251 ng m-2 d-1. In the air-water column-surface sediments system, air-water exchange was the main transport pathway. In order to ensure safety of drinking water resources for local residence, the governments are suggested to work together to reduce PAHs emission and implement new energy policy.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , China , Ecossistema , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Lagos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise
17.
Environ Pollut ; 270: 116060, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33341299

RESUMO

We examined polycyclic aromatic compounds (PACs) and petroleum biomarkers (steranes, hopanes, and terpanes) in radiometrically-dated lake sediment cores from the Athabasca oil sands region (AOSR) and the Peace-Athabasca Delta (PAD) region in Alberta (Canada) to determine whether contributions from petroleum hydrocarbons have changed over time. Two floodplain lakes in the PAD (PAD 30, PAD 31) recorded increased flux of alkylated PACs and increased petrogenic (petroleum-derived) hydrocarbons after ∼1980, coincident with a decline of sediment organic carbon content and a rise of bulk sedimentation rate, likely due to increased Athabasca River flow. A large expansion of upstream oilsands mining, upgrading, and refining may also have contributed to the observed shift to more petrogenic hydrocarbons to sediments since the 1980s. Alkylated PAC flux increased in the floodplain lake analyzed within the AOSR (Saline Lake) since the 1970s-1980s, coincident with a sharp rise in sediment organic carbon content and increased contributions of petrogenic hydrocarbons. These changes identify increased supply of petrogenic PACs occurred as Athabasca River floodwaters waned, and may implicate aerial contributions of petrogenic hydrocarbons from oilsands activity. PACs and petroleum biomarkers (steranes, hopanes, and terpanes) in sediment cores from Saline Lake, PAD 30 and PAD 31 revealed a predominance of petrogenic hydrocarbons in these lakes. In contrast, we recorded minimal petrogenic hydrocarbons in the reference lakes outside the surface minable area of the AOSR and PAD (Mariana Lake and BM11), though we noted slight increases in petrogenic contributions to modern (2010-2016) sediments. We show how a combined analysis of PACs and petroleum biomarkers in sediments is useful to quantify petrogenic contributions to lakes with added confidence and highlight the potential for petroleum biomarkers in lake sediment cores as a novel and effective method to track petroleum hydrocarbons in lake sediment.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Compostos Policíclicos , Poluentes Químicos da Água , Alberta , Biomarcadores , Monitoramento Ambiental , Sedimentos Geológicos , Lagos/análise , Campos de Petróleo e Gás , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise
18.
Sci Total Environ ; 753: 141980, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33207456

RESUMO

The algae biological pump (ABP) effect for hydrophobic organic contaminants in deep oligotrophic lakes and oceans has been well studied. Suspended particulate matter (SPM) plays a connective role in ABP processes. However, little is known about the impacts of ABP effect on the occurrence, source apportionment and toxicity of SPM-bound polycyclic aromatic hydrocarbons (PAHs) in a typically shallow eutrophic lake under strong anthropogenic emissions of PAHs. In this study, we study this gap knowledge on the eutrophic Lake Chaohu, China. SPM-bound PAHs in Lake Chaohu were controlled by anthropogenic emissions in all seasons. Apparent ABP effect only occurred in spring and summer in lake area. Algae blooms in spring and summer significantly increased 46.5% ± 7.9% (mean ± standard deviation) and 19.8% ± 2.4% of Σ21 SPM-bound PAHs, and greatly enhanced their toxicity (1.98 ± 0.46 times in spring and 32.9% ± 4.2% in summer). Therefore, there need more attentions focusing on the coupling effect of persistent toxic substances such as PAHs and harmful algae blooms in aquatic environment for sustainable development. The apparent ABP effect had little influence on their source apportionment. However, it may cause a regime shift for the source apportionment on a short-term scale. Further study could pay more attentions on in-depth and short-term studies on ABP effect.


Assuntos
Proteínas de Membrana Transportadoras , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Lagos/análise , Material Particulado/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
19.
Chemosphere ; 262: 127741, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32781330

RESUMO

In recent years, the dramatic increase in antibiotic use has led to the evolution of antibiotic resistant genes (ARGs), posing a potential risk to human and aquatic ecological safety. In this study, source contribution and correlations between twelve antibiotics and their corresponding ARGs were firstly investigated in surface water in the Fuxian Lake. The results showed that sulfamethoxazole (SMX) (0.98-14.32 ng L-1) and ofloxacin (OFL) (0.77-7.3 ng L-1) were the dominant antibiotics in surface water, whereas erythromycin-H2O (EM-H2O), SMX and OFL posed the medium risk to aquatic organisms. Meanwhile, the mean concentrations of MLs in inflowing rivers were 5.6 times more than those in the lake, which was related to dilution and degradation. Moreover, the facter1 (co-sources L (Living quarters), M (Mining area), A (Agricultural district) and T (tourist area)) contributed 78% of antibiotic concentrations, and the source L was predominant. The results also revealed the prevalence of intL1, sul1 and sul2 in all the sampling sites, and that the abundance of ARGs in the lake was significantly lower (P < 0.01) than that in inflowing rives. Additionally, significant correlations (p < 0.0001) between intL1 and sulfanilamide resistance genes (sul1, sul2) were detected, indicating that intL1 promoted the propagation and they originated from the same anthropogenic sources. Overall, our findings revealed the presence of antibiotics and ARGs and their inconsistent correlations in the Fuxian Lake, which provides a foundation to support further exploration of the occurrence and transmission mechanisms of antibiotics and ARGs.


Assuntos
Antibacterianos/análise , Resistência Microbiana a Medicamentos/genética , Lagos , Poluentes Químicos da Água/análise , China , Lagos/análise , Lagos/microbiologia , Modelos Lineares , Ofloxacino/análise , Análise de Componente Principal , Rios , Sulfametoxazol/análise , Microbiologia da Água
20.
Chemosphere ; 262: 127716, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799137

RESUMO

For the first time the occurrence of 25 organic micropollutants (OMPs) including; 11 personal care products (PCPs), six phthalate ester plasticizers (PEPs) and eight organophosphorus flame retardants (OPFRs) was investigated in 72 water samples obtained from five bays in the Uganda sector of Lake Victoria. In addition, an assessment of the potential ecotoxic risk of the target OMPs to aquatic organisms was conducted. Water samples were analyzed for the target OMPs using gas chromatography coupled with mass spectrometry (GC/MS). All the target PCPs were found in all the water samples with the exception of musk ketone and 2,6-di-tert-butylphenol. Triclosan (89-1400 ng L-1), benzophenone (36-1300 ng L-1), and 4-methylbenzylidine camphor (21-1500 ng L-1) were the most predominant PCPs. All the six plasticizers were found in all the water samples with dibutyl phthalate (350-16 000 ng L-1), and bis-(2-ethylhexyl) phthalate (210-23 000 ng L-1) detected at the highest concentrations. Five OPFRs out of the eight targeted were found in all the water samples. Tricresyl phosphate (25-8100 ng L-1), tris-(2-chloroethyl) phosphate (24-6500 ng L-1) and triphenyl phosphate (54-4300 ng L-1) were the most dominant OPFRs. The highest concentrations of OMPs were recorded in Murchison and Thurston Bays, presumably due to industrial wastewater effluents from the highly industrialized localities of the two Bays. Ecotoxicological risk assessment showed that PCPs (triclosan, musk ketone, and 4-MBC), plasticizers (dibutyl phthalate, bis-(2-ethylhexyl) adipate and bis-(2-ethylhexyl) phthalate) and OPFRs (tricresyl phosphate, triphenyl phosphate and tris-(2-chloroethyl) phosphate) pose a high ecotoxic risk to lives of aquatic organisms (risk quotients, RQ > 1).


Assuntos
Cosméticos/análise , Retardadores de Chama/análise , Lagos/análise , Compostos Organofosforados/análise , Plastificantes/análise , Poluentes Químicos da Água/análise , Animais , Cosméticos/toxicidade , Ecotoxicologia/métodos , Retardadores de Chama/toxicidade , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Organofosforados/toxicidade , Plastificantes/toxicidade , Medição de Risco , Análise Espaço-Temporal , Uganda , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade
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