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1.
Environ Monit Assess ; 196(2): 133, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200356

RESUMO

The present study aims to assess the impact of human activities on the water quality of the Hammam Boughrara dam. It also highlights the crucial importance of sustainable management of water resources in the face of persistent challenges related to various forms of pollution. The study is based on an exhaustive database covering a period spread over 16 years, with monthly measurements of organic pollution indicator parameters, namely BOD5, COD, [Formula: see text],[Formula: see text], [Formula: see text], [Formula: see text], Organic Matter (OM), TDS, Dissolved Oxygen (DO) and pH. The box plots showed an asymmetric distribution of almost all the parameters, with significant seasonal variations in the interquartile (IQR) range. The IQR ranges for [Formula: see text] extends from 0.575 mg/l (summer) to 4.445 mg/l (spring), and for [Formula: see text] from 1.3075 mg/l (autumn) to 1.8625 mg/l (spring). This led to the use of the Spearman method for the analysis of correlations between different parameters. The seasonal study of the five categories of water quality, according to the Organic Pollution Index (OPI), revealed considerable organic pollution. At the 1% significance level, the seasonal correlation between OPI and [Formula: see text] varies between -0.71 and -0.85, while that with [Formula: see text] fluctuates between -0.69 and -0.86. During the period analyzed, the COD/BOD Ratio (CBR) reveals two dominant categories with seasonal variations, i.e. the Moderately Biodegradable Effluents (MBE), with 96 cases, reaching 29 in autumn and 20 in spring. The Difficult to Biodegrade or Non-Biodegradable Effluents (DBE or NBE) category records 94 cases, with a maximum frequency of 26 in winter and minimum of 21 in autumn. These results therefore show the persistence of organic pollution, which had an impact on water quality over the four seasons and throughout the period studied. The results indicate persistent organic pollution affecting water quality. Therefore, prompt actions and sustainable strategies are deemed necessary to mitigate these harmful impacts and to ensure the sustainability of the water resource.


Assuntos
Monitoramento Ambiental , Qualidade da Água , Humanos , Argélia , Estações do Ano , Poluição da Água
2.
Small ; 19(35): e2300559, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37127880

RESUMO

Narrow-bandgap semiconductors are promising photocatalysts facing the challenges of low photoredox potentials and high carrier recombination. Here, a broken-gap heterojunction Bi/Bi2 S3 /Bi/MnO2 /MnOx , composed of narrow-bandgap semiconductors, is selectively decorated by Bi, MnOx nanodots (NDs) to achieve robust photoredox ability. The Bi NDs insertion at the Bi2 S3 /MnO2 interface induces a vertical carrier migration to realize sufficient photoredox potentials to produce O2 •- and • OH active species. The surface decoration of Bi2 S3 /Bi/MnO2 by Bi and MnOx cocatalysts drives electrons and holes in opposite directions for optimal photogenerated charge separation. The selective cocatalysts decoration realizes synergistic surface and bulk phase carrier separation. Density functional theory (DFT) calculation suggests that Bi and MnOx NDs act as active sites enhancing the absorption and reactants activation. The decorated broken-gap heterojunction demonstrates excellent performance for full-light driving organic pollution degradation with great commercial application potential.

3.
Environ Res ; 239(Pt 1): 117407, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37838200

RESUMO

To effectively differentiate toxic aminophenol isomers, a kind of spindle-shaped Cu-Ru bimetal mesoporous nanozyme (Cu-Ru MPNZ) with high specific surface was developed by one-pot homogeneous reduction method, directed by hexadecyl trimethyl ammonium bromide (CTAB) in this work. By virtue of the distinctive microstructure, Cu-Ru MPNZ expressed superior bi-functional oxidase- and peroxidase-mimic activity to catalyze the oxidation of 3,3',5,5,'-tetramethylbenzidine (TMB) and 2,2'-azinobis (3-ethylbenzothiazoline-6- sulfonic acid) ammonium salt (ABTS) with low Michaelis-Menten constants and quick reaction rates. Especially, toxic aminophenol isomers could exclusively react with the oxydates of TMB or ABTS to express differentiable signals in color. Under the optimal conditions, Cu-Ru MPNZ was successfully applied for visual differentiation of toxic aminophenol isomers in real aqueous, juices and medicinal samples with low detection limits (1.60 × 10-8 mol/L for o-aminophenol and 3.25 × 10-8 mol/L for m-aminophenol) and satisfactory recoveries (96.6-103.5%). The different recognition mechanisms of Cu-Ru MPNZ to toxic o- and m-aminophenol isomers were proposed for the first time as far as we known. This work will provide a potential way to monitor different organic isomer pollution in future.


Assuntos
Nanosferas , Nanosferas/toxicidade , Aminofenóis/toxicidade , Cetrimônio
4.
J Environ Manage ; 342: 118254, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37295147

RESUMO

Chlorophenols represent one of the most abundant families of toxic pollutants emerging from various industrial manufacturing units. The toxicity of these chloroderivatives is proportional to the number and position of chlorine atoms on the benzene ring. In the aquatic environment, these pollutants accumulate in the tissues of living organisms, primarily in fishes, inducing mortality at an early embryonic stage. Contemplating the behaviour of such xenobiotics and their prevalence in different environmental components, it is crucial to understand the methods used to remove/degrade the chlorophenol from contaminated environment. The current review describes the different treatment methods and their mechanism towards the degradation of these pollutants. Both abiotic and biotic methods are investigated for the removal of chlorophenols. Chlorophenols are either degraded through photochemical reactions in the natural environment, or microbes, the most diverse communities on earth, perform various metabolic functions to detoxify the environment. Biological treatment is a slow process because of the more complex and stable structure of pollutants. Advanced Oxidation Processes are effective in degrading such organics with enhanced rate and efficiency. Based on their ability to generate hydroxyl radicals, source of energy, catalyst type, etc., different processes such as sonication, ozonation, photocatalysis, and Fenton's process are discussed for the treatment or remediation efficiency towards the degradation of chlorophenols. The review entails both advantages and limitations of treatment methods. The study also focuses on reclamation of chlorophenol-contaminated sites. Different remediation methods are discussed to restore the degraded ecosystem back in its natural condition.


Assuntos
Clorofenóis , Poluentes Ambientais , Poluentes Químicos da Água , Clorofenóis/química , Ecossistema , Poluentes Ambientais/química , Oxirredução , Poluentes Químicos da Água/metabolismo
5.
Environ Monit Assess ; 195(3): 435, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36856891

RESUMO

This study was carried out to determine the spatiotemporal distributions of organic pollution parameters in the Meriç-Ergene River Basin subjected to intensive agricultural and industrial pressure. A total of 5 basin components, including Anadere (A), Çorlu (Ç), Tunca (T), Meriç (M), and Ergene (E) rivers, and 9 stations (A1, Ç1, T1, M1-M2, and E1-E4) were identified in the watershed, and surface water samples were collected in the dry (end of summer) and wet (end of winter) seasons of 2021-2022. The Water Quality Index (WQI) and Nutrient Pollution Index (NPI) were applied to the data to evaluate the overall water quality characteristics. The Chronic Daily Index (CDI), Hazard Quotient (HQ), and Hazard Index (HI) were applied to the data to reveal the probable noncarcinogenic health risks of organic contaminants. Cluster Analysis (CA) and Principal Component Analysis (PCA) were applied to the data to classify the sampling sites and identify the source apportionment of organic pollution parameters. The recorded spatiotemporal averages of the investigated parameters in the basin are as follows: 6.26 mg/L for DO, 9 for pH, 1626 µS/cm for EC, 985 mg/L for TDS, 1 ‰ for salinity, 6.88 mg/L for nitrate, 0.1 mg/L for nitrite, 1.8 mg/L for phosphate, 81 mg/L for sulfate, and 473 mg/L for chloride. The results indicate that the most contaminated components of the basin are Çorlu Stream and Ergene River, and in addition to their quite high salt and nutrient content, they have extreme hypoxic conditions to the extent that it is impossible for many aquatic organisms to live. The contamination degrees of the investigated basin components were determined using the organic pollution risk assessment indices as follows: Çorlu Stream > Ergene River > Anadere Stream > Tunca River > Meriç River.


Assuntos
Artrópodes , Poluentes Ambientais , Animais , Rios , Monitoramento Ambiental , Poluição Ambiental , Agricultura , Hipóxia
6.
Environ Monit Assess ; 195(12): 1402, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37917378

RESUMO

In the present work, an investigation was performed based on the genera and species stated in Palmer pollution index to show the extent of organic pollution in the surface water of the Tawi watershed in the Jammu province of the Union Territory of Jammu and Kashmir using algal pollution indices. Sampling was carried out for two seasons, pre-monsoon (PRM) and post-monsoon (POM), at 16 locations distributed over the entire Tawi watershed. The physico-chemical variables like water temperature, pH, electrical conductivity, TDS, total alkalinity, total hardness, DO, BOD, COD, nitrate, and phosphate were analyzed. The seasonal distribution of the pollution-tolerant algal genera and species was recorded and the algal pollution index for both genus (AGP index) and species (ASP index) was also calculated. The concentration of BOD, COD, and nitrate in the sampled river water was found to be higher during the PRM season as compared to the POM season. The lower stretch of the watershed (Jammu Sub-Watershed) falls in class IV-V as per the polluted river stretch priority ranking based on BOD levels as BOD levels are >3 mg/L in the downstream locations during both seasons. A total of 23 algal taxa belonging to 8 families, Chlorophyceae (4 algal genera), Cyanophyceae (2 algal genera), Bacillariophyceae (7 algal genera), Zygnematophyceae (3 algal genera), Trebouxiophyceae (2 algal genera), Ulvophyceae (1 algal genus), Mediophyceae (1 algal genus), and Euglenophyceae (3 algal genera), have been reported in the Tawi watershed. The results of the Palmer indices showed a lack of organic pollution in the upstream, varying pollution levels in the midstream, and partially high to very high organic pollution levels in the downstream of the watershed. Comparative temporal analysis of the distribution of pollution-tolerant algal genera and species showed more organic pollution during PRM. Navicula and Cymbella were found to be the most abundant genera in almost all the stations, whereas Ulothrix, Cocconeis, Anacystis, and Crucigenia were the least recorded genera in the entire watershed. The results will enhance the understanding of the health status of the watershed, and provide database for watershed vulnerability assessment for sustainability and watershed management with spatio-temporal improvement.


Assuntos
Clorófitas , Diatomáceas , Humanos , Qualidade da Água , Monitoramento Ambiental/métodos , Nitratos , Rios , Água Doce , Compostos Orgânicos , Estações do Ano
7.
Environ Sci Technol ; 56(12): 8034-8042, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35584092

RESUMO

Phytoremediation is a potentially cost-effective and environmentally friendly remediation method for environmental pollution. However, the safe treatment and resource utilization of harvested biomass has become a limitation in practical applications. To address this, a novel manganese-carbon-based single-atom catalyst (SAC) method has been developed based on the pyrolysis of a manganese hyperaccumulator, Phytolacca americana. In this method, manganese atoms are dispersed atomically in the carbon matrix and coordinate with N atoms to form a Mn-N4 structure. The SAC developed exhibited a high photooxidation efficiency and excellent stability during the degradation of a common organic pollutant, rhodamine B. The Mn-N4 site was the active center in the transformation of photoelectrons via the transfer of photoelectrons between adsorbed O2 and Mn to produce reactive oxygen species, identified by in situ X-ray absorption fine structure spectroscopy and density functional theory calculations. This work demonstrates an approach that increases potential utilization of biomass during phytoremediation and provides a promising design strategy to synthesize cost-effective SACs for environmental applications.


Assuntos
Recuperação e Remediação Ambiental , Phytolacca americana , Carbono/metabolismo , Carvão Vegetal , Manganês/química , Phytolacca americana/metabolismo
8.
Environ Sci Technol ; 56(23): 16633-16642, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36332100

RESUMO

The organic composition of coastal sea spray aerosol is important for both atmospheric chemistry and public health but remains poorly characterized. Coastal waters contain an organic material derived from both anthropogenic processes, such as wastewater discharge, and biological processes, including biological blooms. Here, we probe the chemical composition of the organic fraction of sea spray aerosol over the course of the 2019 SeaSCAPE mesocosm experiment, in which a phytoplankton bloom was facilitated in natural coastal water from La Jolla, California. We apply untargeted two-dimensional gas chromatography to characterize submicron nascent sea spray aerosol samples, reporting ∼750 unique organic species traced over a 19 day phytoplankton bloom experiment. Categorization and quantitative compositional analysis reveal three major findings. First, anthropogenic species made up 30% of total submicron nascent sea spray aerosol organic mass under the pre-bloom condition. Second, biological activity drove large changes within the aerosolized carbon pool, decreasing the anthropogenic mass fraction by 89% and increasing the biogenic and biologically transformed fraction by a factor of 5.6. Third, biogenic marine organics are underrepresented in mass spectral databases in comparison to marine organic pollutants, with more than twice as much biogenic aerosol mass attributable to unlisted compounds.


Assuntos
Partículas e Gotas Aerossolizadas , Fitoplâncton , Aerossóis/química , Oceanos e Mares
9.
Environ Res ; 214(Pt 3): 114044, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35985491

RESUMO

The development of agricultural activities and industrialization recently has various adverse impacts on living organisms. The ever-increasing problem of organic pollution has been an environmental concern to the community. Among these, phenolic pollutants like 2,4-dichlorophenol (2,4-DCP), phenol, 2-chlorophenol (2-CP), and bisphenol-A (BPA) are priority toxic pollutants that are continuously released into environment from many industries. In this work, a biocompatible zinc oxide incorporated polyethylene glycol functionalized reduced graphene oxide composite (RGO-PEG-ZnO) was synthesized and explored for the adsorptive removal of toxic phenolic pollutants from water. The optimized adsorption parameters were solution pH 7, adsorption time 60 min, temperature 25 °C, and dosage 0.25 g/L. The isotherms were well fitted by the Langmuir model for BPA and phenol, whereas for 2-CP, and 2,4-DCP, Freundlich was the best-fitted model, and the maximum uptake of BPA, phenol, 2-CP, and 2,4-DCP were 485.756, 511.248, 531.804, 570.641 mg/g, respectively. The kinetic data for all the phenolic pollutants follow the pseudo-second-order model. The thermodynamic analysis shows that Gibb's free energy (ΔGo) values for all the pollutants were negative, confirming that the process was spontaneous. The positive values of change in enthalpy (ΔHo) 28.261, 37.205, 46.182, and 61.682 kJ/mol for BPA, phenol, 2-CP, and 2,4-DCP, respectively, confirm that the above adsorption process was endothermic. The composite can be used for up to five cycles with a small reduction in the removal percentage. Adsorption performance of the synthesized composite for synthetic industrial effluents shows that up to 86.54% removal occurred in 45 min adsorption time. Based on the remarkably rapid adsorption and high adsorption capacity, RGO-PEG-ZnO composite can be considered an efficient adsorbent for treating phenolic pollutants from wastewater.


Assuntos
Poluentes Químicos da Água , Óxido de Zinco , Grafite , Fenol , Fenóis , Polietilenoglicóis , Águas Residuárias , Poluentes Químicos da Água/análise
10.
Molecules ; 27(18)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36144848

RESUMO

Due to the frequent oil/organic solvent leakage, efficient oil/water separation has attracted extensive concern. However, conventional porous materials possess nonpolar building units, which reveal relatively weak affinity for polar organic molecules. Here, two different polarities of superhydrophobic porous aromatic frameworks (PAFs) were synthesized with respective orthoposition and paraposition C=O groups in the PAF linkers. The conjugated structure formed by a large number of alkynyl and benzene ring structures enabled porous and superhydrophobic quality of PAFs. After the successful preparation of the PAF solids, PAF powders were coated on polyester fabrics by a simple dip-coating method, which endowed the resulting polyester fabrics with superhydrophobicity, porosity, and excellent stability. Based on the unique structure, the oil/water separation efficiency of two superhydrophobic flexible fabrics was more than 90% for various organic solvents. Polar LNU-26 PAF showed better separation performance for the polar oils. This work takes the lead in adopting the polar groups as building units for the preparation of porous networks, which has great guiding significance for the construction of advanced oil/water separation materials.

11.
Environ Monit Assess ; 195(1): 210, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36534270

RESUMO

This study evaluates the changes in the structure of the macroinvertebrate functional feeding groups (FFGs) of the Hassar Stream (northeast of Casablanca) following the installation of Mediouna's wastewater treatment plant (WWTP). Data on water quality and the macroinvertebrate fauna were collected at seven sample points from November 2013 to October 2014. Macroinvertebrates were used to assess the impact of physicochemical and hydromorphological properties on the FFG organization and resilience. Redundancy analysis (RDA) was employed to examine the distribution of FFGs along this stream. Based on the FFGs' relative abundance, collector-gatherers account for 39.06% of the macroinvertebrates' assemblage, followed by shredders (28.41%), collector-filters (18.76%), scrapers (7.16%), and predators (6.6%). The FFG ratios revealed that the environment was highly heterotrophic (P/R < 0.75), and all studied stations had relatively stable substrates. In addition, the ratios indicated that the studied stations had a functional riparian zone (CPOM/FPOM > 0.25), except for stations S1 and S2. Simultaneously, the RDA model revealed that the distribution of the FFGs closely followed fluctuations in the water quality (BOD5, NH4+, PO43-, EC, and Cl-) and hydromorphic properties (flow and depth). These findings highlight the importance of studying macroinvertebrate FFGs as a complementary way to assess the aquatic ecosystems' ecological integrity and resilience following anthropogenic impact reduction.


Assuntos
Ecossistema , Invertebrados , Animais , Rios/química , Monitoramento Ambiental , Marrocos
12.
Environ Monit Assess ; 194(2): 103, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35039924

RESUMO

Allogenic recharge is an important source of pollution affecting karst protected terrains. In order to prevent the introduction of contaminants and the deterioration of karst phenomena, it is necessary to determine buffer zones that require protection, which is sometimes difficult, especially in densely populated areas. A multicriterial approach for the determination of buffer zones was proposed and verified. The method combines two criteria to identify those watercourses whose catchments lying outside the protected area need to be protected, namely the water quality index and the mass flow of pollutants. The case study was performed in the Moravian Karst (Czech Republic), which is fed by more than 10 small allogenic watercourses. The study proved that not only water quality, but also mass flow of pollutants conditioned by watercourse discharge must be considered. This approach can be adapted for all types of protected landscape areas with water pollution originating in surrounding areas.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água , República Tcheca , Poluentes Químicos da Água/análise , Poluição da Água , Qualidade da Água
13.
Indian J Med Res ; 153(3): 348-357, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33906998

RESUMO

Fisheries comprise the fastest growing sector meeting the global protein requirements. Being an affordable enterprise, it is considered a safe source of food and the muscles of healthy fishes are almost sterile. However, a multitude of hazards (biological, chemical, and environmental) can be introduced into aquaculture throughout the production and supply chain. Also, it can originate from unsuitable farming practices, environmental pollution, and socio-cultural habits prevailing in various regions. Hence, with an increasing global population and demands for aquacultural products, assessment and regulation of food safety concerns are becoming significantly evident. Ensuring safe, secure, affordable, and quality food for all in a global context is pragmatically difficult. In this context, it is quite imperative to understand the ecology and dynamics of these hazards throughout the entire production chain in a One Health approach. Here, we discuss the issues and challenges faced in the fisheries sector as a whole and the need for a One Health approach to overcome such hurdles.


Assuntos
Pesqueiros , Saúde Única , Animais , Aquicultura , Inocuidade dos Alimentos , Abastecimento de Alimentos , Humanos
14.
J Environ Manage ; 289: 112522, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33848878

RESUMO

COVID-19 pandemic has caused profound impacts on human life and the environment including freshwater ecosystems globally. Despite the various impacts, the pandemic has improved the quality of the environment and thereby creating an opportunity to restore the degraded ecosystems. This study presents the imprints of COVID-19 lockdown on the surface water quality and chemical characteristics of the urban-based Bagmati River Basin (BRB), Nepal. A total of 50 water samples were collected from 25 sites of BRB during the monsoon season, in 2019 and 2020. The water temperature, pH, electrical conductivity, total dissolved solids, dissolved oxygen (DO), and turbidity were measured in-situ, while the major ions, total hardness, biological oxygen demand (BOD), and chemical oxygen demand (COD) were analyzed in the laboratory. The results revealed neutral to mildly alkaline waters with relatively moderate mineralization and dissolved chemical constituents in the BRB. The average ionic abundance followed the order of Ca2+ > Na+ > Mg2+ > K+ > NH4+ for cations and HCO3-> Cl- > SO42- > NO3- > PO43- for anions. Comparing to the pre-lockdown, the level of DO was increased by 1.5 times, whereas the BOD and COD were decreased by 1.5 and 1.9 times, respectively during the post-lockdown indicating the improvement of the quality water which was also supported by the results of multivariate statistical analyses. This study confirms that the remarkable recovery of degraded aquatic ecosystems is possible with limiting anthropic activities.


Assuntos
COVID-19 , Poluentes Químicos da Água , Controle de Doenças Transmissíveis , Ecossistema , Monitoramento Ambiental , Humanos , Nepal , Pandemias , Rios , SARS-CoV-2 , Poluentes Químicos da Água/análise , Qualidade da Água
15.
Environ Monit Assess ; 193(6): 360, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34037847

RESUMO

Halophytes are the good candidates in coastal saline areas which could be irrigated with wastewater. The purpose of this study was to evaluate the soil-water-plant system under control and wastewater irrigation (containing toxic elements and organic matter) at three durations (vegetative, flowering, and reproductive stages) and two exposure times (2 and 4 days in each stage). The results obtained in the experimental tests for wastewater irrigation indicated that the Salicornia is efficient for the removal of chemical oxygen demand (61%), biochemical oxygen demand (74%), total suspended solids (47.6%), and ammoniacal nitrogen (64%) at the reproductive stage. At the same time, the average nitrate concentration increased to 51.3 mg L-1 with more solids. Regardless of wastewater irrigation duration, irrigation with wastewater significantly increased organic matter, nitrogen, phosphorus, and potassium of the soil. The Mg2+ and Ca2+ contents in the aboveground biomass of the plants were also high ranged from 0.58 to 1%, and 0.43 to 0.68 mg g-1 DW, respectively. All the exchangeable cations other than Na+ were higher for wastewater irrigation at the flowering stage. Plants maintained noticeably higher Ca2+/Na+ and K+/Na+ ratios in the roots than those in the shoots except for 4 days after the reproductive stage. S. europaea is well adapted to grow in wastewater irrigation and can tolerate hypoxic conditions through improving water and soil quality.


Assuntos
Chenopodiaceae , Poluentes Ambientais , Irrigação Agrícola , Monitoramento Ambiental , Solo , Águas Residuárias
16.
Environ Monit Assess ; 193(8): 494, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34279739

RESUMO

The monitoring and assessment of a river system is a complex process and not restricted to urban areas only. The discharge of wastewater drains in the river increases the river system complexity further. The abstraction of freshwater at regular intervals and the discharge of the wastewater from various sources cause significant spatial and temporal variation in water quality. The multivariate statistical analysis is performed to identify water quality parameters' variability on the 5-year dataset from four monitoring sites. Hierarchical agglomerative cluster analysis (HACA) and principal component analysis (PCA) are applied to characterize the water quality parameters and identify the significant pollution sources. The clusters are formed considering the similarities between parameters, and eigenvalues are determined from the covariance of parameters. The box plots are designed to identify the spatial and temporal variations. The highest variability of the first principal component is 60.78% of the total variance at the second sampling location, the ITO bridge. The significant varifactors obtained from the PCA indicate the parameters responsible for the maximum variation in water quality. The study reveals the importance of multivariate statistical techniques in identifying a pattern of variability of parameters and developing management strategies to improve river water quality by identifying dominant parameters causing the maximum degradation in water quality.


Assuntos
Rios , Poluentes Químicos da Água , Análise por Conglomerados , Monitoramento Ambiental , Índia , Análise de Componente Principal , Poluentes Químicos da Água/análise , Qualidade da Água
17.
Ecotoxicology ; 29(6): 650-668, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32350642

RESUMO

The phytoplankton diversity and community response to physicochemical variables in mangrove zones of Guangdong Province along the South China coast was investigated from October to December, 2017. This study was set to investigate the phytoplankton community structure in the mangrove zone and assess the relationship between the physicochemical variables and phytoplankton species diversity. Physicochemical variables such as water temperature, total dissolve solids (tds), pH, salinity, turbidity, electrical conductivity (EC) and nutrient salts were measured in situ across the 27 stations. A total of 451 species of phytoplankton were identified belonging to 10 groups (Bacillariophta > Cyanophyta > Chlorophyta > Euglenophyta > Dinoflagellate > Eubacteria > Ochrophyta > Crytophyta > Rhodophyta > Charophyta) and quantified to constitute a standing crop of 7.11 × 108 cells dm-3. The principal component analysis (PCA) reveals that reactive nitrate, phosphate, electrical conductive (EC) and turbidity were the best abiotic factors that controlled the phytoplankton community structure in the area. However, Cannon Corresponding Analysis and Pearson correlation have explicitly revealed the impact of reactive nitrate, phosphate, EC and turbidity on the phytoplankton community structure. For instance, the CCA ordination revealed that species richness and evenness were positively influenced by reactive nitrate but negatively affected by EC, turbidity and water temperature. Diatoms were mostly controlled by total dissolved solids (tds) and salinity, whereas Euglena, cyanobacteria and green algae were impacted EC and turbidity, apart from the general contribution of the nutrient salts as delineated by CCA ordination. The Shannon diversity index value exposed different levels of organic pollution across the mangrove zone of which GD37 was the most impacted station.


Assuntos
Biodiversidade , Monitoramento Ambiental , Fitoplâncton , Áreas Alagadas , China , Clorófitas , Cianobactérias , Diatomáceas , Dinoflagellida , Eutrofização , Nitratos , Salinidade , Estações do Ano
18.
Environ Geochem Health ; 42(3): 781-793, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30864071

RESUMO

Differences in bird eggshell thicknesses occur due to numerous factors, including thinning due to persistent organic pollutants. Not only does thinning weaken the shell; weaker shells combined with elevated ambient temperature and changes in humidities may result in changes in water loss rates from the egg contents. Therefore, thinner eggshells raise concern of water being lost faster than normal at lower relative humidities, which may affect hatching. To investigate the combined effects, we developed and tested an effective method that measures water loss through different thickness eggshells at controlled temperatures and relative humidities to assist in ascertaining the combined effects of climate change (temperature and humidity) and changes in eggshell thickness on bird reproduction. The fastest rate of loss was at 40% RH at 40 °C (0.1 mL/cm2/day), and the slowest was at 22 °C at 80% RH (0.02 mL/cm2/day). Eggshell thickness had a significant effect on water loss at all humidity treatments, except at the highest temperature and humidity treatment (80% RH and 40 °C). Temperature explained 40% of the variance, RH explained 20%, and interactions between temperature and humidity explained 15% of the variance (repeated-measures, two-way ANOVA). Generalized linear analyses revealed that both factors temperature and humidity contributed significantly in any two-way combinations. We have laid the ground for a system to test the combined effects of temperature and humidity changes associated with climate change and eggshell thinning associated with pollutants, on water loss across eggshells.


Assuntos
Mudança Climática , Casca de Ovo/química , Água/química , Animais , Aves/fisiologia , Galinhas , Ovos , Umidade , Temperatura
19.
Environ Monit Assess ; 192(5): 283, 2020 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-32285216

RESUMO

Organic contaminants can be accumulated in aquatic systems even at trace concentrations with potential threats to the environment and human health. The present study has been performed to evaluate the effects of organochlorines and polyaromatic hydrocarbons on surface sediments of the Meliane river catchment. Their determination provides an essential scientific approach for a better understanding of the expected sources and the processes of bioaccumulation. The concentrations of saturated hydrocarbons in extractable organic matter of the dry sediment were found ranging from 0.58 to 3 83 µg kg-1 and PAHs content ranged from 63 to 131 µg kg-1. These results indicated the adherence of Oued Meliane to the pollution of the Tunis Gulf. The fraction of saturated hydrocarbons extracted from the sediments of Oued Meliane included a majority of organic compounds of biogenic nature with a small oil input. In addition, characterization with the TAR index and the LMW/HMW index confirmed that terrigenous inputs in this fraction are more abundant than aquatic inputs. The characterization of PAHs fraction has shown its pyrolitic origin with a predominance of high molecular weight PAHs.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Sedimentos Geológicos , Humanos , Hidrocarbonetos Clorados , Rios
20.
Artigo em Inglês | MEDLINE | ID: mdl-30729857

RESUMO

The goal of this study was to determined polychlorinated biphenyls (PCBs) and organochlorine pesticides in the depot fat of roe deer (Capreolus capreolus) coming from south-western Slovakia. The mutual correlations of the organic pollutants were analyzed. The study included dichlorodiphenyltrichloroethane (DDT), hexachlorobenzen (HCB), alpha-hexachlorocyclohexane and beta-hexachlorocyclohexane (α + ß-HCH), gamma-hexachlorocyclohexane (γ-HCH), and polychlorinated biphenyls (PCB-delor). The gas chromatograph with an electron capture detector ECD was used for analysis. The accumulations of organic pollutant in depot fat of roe deer were in following order: DDT > PCB-delor > α + ß-HCH > HCB > γ-HCH. Among all pollutants, DDT was accumulated significantly in the highest level in the samples. The significantly higher content of DDT, HCB, α + ß-HCH, and γ-HCH was detected in the adult animals when compared to the juveniles. Some strong positive correlations among pollutants, between HCB and DDT, α + ß-HCH and HCB, α + ß-HCH and HCB, between γ-HCH and other pollutants, and between PCB-delor and γ-HCH were found. Game animals are a part of human food chain and monitoring of the environment pollution by PCBs and other organic pollutants are worthy to study.


Assuntos
Tecido Adiposo/química , Cervos/metabolismo , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Envelhecimento/metabolismo , Animais , Feminino , Humanos , Hidrocarbonetos Clorados/análise , Masculino , Fatores Sexuais , Eslováquia
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