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1.
Water Res ; 171: 115453, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31918385

RESUMO

This paper discusses the abiotic and biotic processes in the in-situ control of biogenic hydrogen sulfide generated from microbial sulfate reduction by ferric (FeIII) (hydr)oxides (FeOOH) granules in the sediments of polluted urban waters. Granular ferric hydroxide (GFH, ß-FeOOH) and granular ferric oxide (GFO, α-FeOOH) dosed in the organic- and sulfate-rich sediments had 180% and 19% higher sulfide removal capacities than those used for the purely abiotic removal of dissolved sulfide, respectively. The enhancement was attributable to the involvement of the biotic pathways, besides the abiotic pathways (mainly sulfide oxidation). The FeOOH granules stimulated the microbial reduction of surface FeIII by iron-reducing bacteria (e.g., Desulfovibrio and Carnobacterium), and increased the microbial sulfate reduction by 24%-30% under an organic-rich condition, likely due to the enhanced organic fermentation. The microbial iron reduction significantly enhanced the removal of the formed biogenic hydrogen sulfide through increasing sulfide precipitation because it remarkably promoted the release of Fe2+ ions from the granule surface, likely due to the involvement of siderophores as ligands. This biotic pathway led to the formation of amorphous FeS(s) as a major sulfur product (56%-81%), instead of elemental sulfur. The enhancement in the sulfide control performance was much more pronounced when the poorly ordered GFH was used, because of the faster Fe2+ release, compared to the highly ordered GFO. The abiotic and biotic mechanisms elucidated in this study provide insights into the iron-sulfur chemistry in the sediments of various polluted waters (e.g., storm drains, urban rivers, and estuary), where the manually-dosed and naturally-occurring FeIII (hydr)oxides control biogenic hydrogen sulfide.


Assuntos
Compostos Férricos , Sulfeto de Hidrogênio , Sedimentos Geológicos , Ferro , Oxirredução , Rios , Poluição da Água
2.
Water Res ; 171: 115435, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31927096

RESUMO

Escherichia coli levels in recreational waters are often used to predict when fecal-associated pathogen levels are a human health risk. The reach of the Chattahoochee River that flows through the Chattahoochee River National Recreation Area (CRNRA), located in the Atlanta-metropolitan area, is a popular recreation area that frequently exceeds the U.S. Environmental Protection Agency beach action value (BAV) for E. coli. A BacteriALERT program has been implemented to provide real-time E. coli estimates in the reach and notify the public of potentially harmful levels of fecal-associated pathogens as indicated by surrogate models based on real-time turbidity measurements from continuous water quality monitoring stations. However, E. coli does not provide information about the sources of fecal contamination and its accuracy as a human health indicator is questionable when sources of contamination are non-human. The objectives of our study were to investigate, within the Park and surrounding watersheds, seasonal and precipitation-related patterns in microbial source tracking marker concentrations of possible sources (human, dog, and ruminant), assess correlations between source contamination levels and culturable E. coli levels, determine which sources best explained model-based E. coli estimates above the BAV and detection of esp2 (a marker for the esp gene associated with pathogenic strains of Enterococcus faecium and Enterococcus faecalis), and investigate associations between source contamination levels and land use features. Three BacteriALERT sites on the Chattahoochee River were sampled six times per season in the winter and summer from December 2015 through September 2017, and 11 additional stream sites (synoptic sites) from the CRNRA watershed were sampled once per season. Samples were screened with microbial source tracking (MST) quantitative PCR (qPCR) markers for humans (HF183 Taqman), dogs (DogBact), and ruminants (Rum2Bac), the esp2 qPCR marker, and culturable E. coli. At the BacteriALERT sites, HF183 Taqman concentrations were higher under wet conditions DogBact concentrations were greater in the winter and under wet conditions, and Rum2Bac concentrations were comparatively low throughout the study with no difference across seasons or precipitation conditions. Concentrations of HF183 Taqman, DogBact, and Rum2Bac were positively correlated with culturable E. coli concentrations; however, DogBact had the largest R2 value among the three markers, and the forward stepwise regression indicated it was the best predictor of culturable E. coli concentrations at the BacteriALERT sites. Recursive partitioning indicated that BAV exceedances of model-based E. coli estimates were best explained by DogBact concentrations ≥3 gene copies per mL (CN/mL). Detections of esp2 at BacteriALERT sites were best explained by DogBact concentrations ≥11 CN/mL, while detections of esp2 at synoptic sites were best explained by HF183 Taqman ≥29 CN/mL. At the synoptic sites, HF183 Taqman levels were associated with wastewater treatment plant density. However, this relationship was driven primarily by a single site, suggesting possible conveyance issues in that catchment. esp2 detections at synoptic sites were positively associated with development within a 2-km radius and negatively associated with development within the catchment, suggesting multiple sources of esp2 in the watershed. DogBact and Rum2Bac were not associated with the land use features included in our analyses. Implications for Park management include: 1) fecal contamination levels were highest during wet conditions and in the off season when fewer visitors are expected to be participating in water-based recreation, 2) dogs are likely contributors to fecal contamination in the CRNRA and may be sources of pathogenic bacteria indicating further investigation of the origins of this contamination may be warranted as would be research to understand the human health risks from exposure to dog fecal contamination, and 3) high levels of the human marker at one site in the CRNRA watershed suggests more extensive monitoring in that catchment may locate the origin of human fecal contamination detected during this study.


Assuntos
Escherichia coli , Rios , Animais , Cães , Monitoramento Ambiental , Fezes , Humanos , Recreação , Estações do Ano , Microbiologia da Água , Poluição da Água
4.
Water Environ Res ; 92(1): 35-41, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31433097

RESUMO

Pinpointing water pollution sources using host-specific gastrointestinal microbes, known as microbial source tracking (MST), have significant benefits for countries with water quality management issues related to pollution. A recently discovered bacteriophage, crAssphage, shows promise as a human-specific MST marker. However, loss of genetic materials during the recovery and the detection processes could alter the ability to measure virus quantities in a water sample. This study determined the crAssphage recovery efficiencies in water sources, including seawater, freshwater, and influent and effluent from a wastewater treatment plant, by spiking natural crAssphage concentrates prior to DNA extraction and quantitative PCR analysis. The results showed that river and seawater with no or low crAssphage background experienced no recovery loss. Evaluating recovery efficiencies in samples with high crAssphage backgrounds posed a challenge due to the inability to prepare high crAssphage titers. This study highlights the importance of intra-laboratory assessment of recovery efficiency in environmental samples for retrieving absolute crAssphage quantification with correction of bias among water samples and increase in data accuracy. PRACTITIONER POINTS: In laboratory assessment of recovery efficiency is crucial for bias correction and data accuracy for absolute crAssphage quantification in water samples. No loss in crAssphage recovery was observed in river and seawater that contained no or low crAssphage backgrounds. Inability to prepare high crAssphage spike concentrations remains the major limitation for evaluating recovery in samples with high crAssphage backgrounds. The results underline the importance of evaluating method recovery in real environmental samples that reflect actual matrix effect. Absolute crAssphage quantification, as human-specific pollution marker, could be used for prioritizing water quality restoration and area-based management plan.


Assuntos
Esgotos , Água , Monitoramento Ambiental , Fezes , Humanos , Concentração de Íons de Hidrogênio , Microbiologia da Água , Poluição da Água
5.
Water Environ Res ; 92(1): 5-10, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31350936

RESUMO

The Metropolitan Water Reclamation District of Greater Chicago adopted the Tunnel and Reservoir Plan (TARP) to reduce combined sewer overflow (CSO) events in the Chicago region. The Thornton Composite Reservoir (TCR) became operational in 2015 providing an additional 30 million m3 of CSO-impacted stormwater capacity. In the United States, no other mega reservoirs are in operation to provide as a reference to study the long-term impacts of biosolids operations in water resource recovery facilities. The mean daily volume pumped from the Calumet TARP system to the Calumet Plant increased 144-238 m3 from 2012-2014 to 273-360 m3 from 2016-2018. Overall annual digester feed solids for the 2016-2018 post-TCR period were 28,182 Mg, which was 11 percent less than the mean for the 2012-2014 period of 31,745 Mg. Annual digester draw solids for the 2016-2018 post-TCR period were 19,422 Mg, which were 4 percent less than the 2012-2014 pre-TCR period mean of 20,190 Mg. This paper demonstrated a decrease in digester feed loading to the Calumet Plant and, ultimately, a decrease in digester draw solids with an overall increase in plant and TARP flow in the years following operation of the TCR for the capture and treatment of CSO-impacted stormwater. PRACTITIONER POINTS: Reservoirs capturing combined sewer overflow-impacted stormwater improve water quality of local waterways. Mega reservoirs may impact solids loading to water resource recovery facilities. Hydraulic loading to water resource recovery facilities may be substantial with mega reservoirs.


Assuntos
Movimentos da Água , Esgotos , Água , Poluição da Água , Qualidade da Água
6.
Sci Total Environ ; 701: 134521, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31715483

RESUMO

Exposure to disinfection byproducts (DBPs) in municipal water mainly occurs through ingestion, inhalation during showering, house cleaning and dermal permeation. While showering, the air-phase DBPs [e.g., trihalomethanes (THMs)] can pose risk to humans through inhalation pathway. In assessing inhalation risk during showering, current approaches assume negligible initial concentrations of air-phase THMs in shower stalls, which may not be realistic in places with common shower stalls (e.g., gymnasiums). The time difference between successive showering events in these places is likely to be minimal, resulting in significant initial concentrations of THMs due to prior showering events. In this study, exposure to air-phase THMs during the successive showering events were predicted. In the 2nd showering event, averages of chronic daily intake (CDI), cancer risk (CR) and hazard index (HI) were 1.82, 1.83 and 1.85 times the CDI, CR and HI in the first event, respectively. In the 3rd event, these were 2.50, 2.54 and 2.58 times, respectively. The increasing trends of CDI, CR and HI were observed for up to the 9th event (5.06, 4.98 and 5.60 times, respectively). By widening the time-gap between the successive showering events, reducing showering duration and enhancing ventilation, human exposure and risk can be controlled.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Higiene , Trialometanos/análise , Poluição da Água/estatística & dados numéricos , Humanos , Medição de Risco , Poluentes Químicos da Água/análise
7.
Chemosphere ; 240: 124893, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550585

RESUMO

Water pollution with heavy metals is a global problem. Using microbial adsorbents to remediate water bodies contaminated with heavy metals has been garnering considerable attention. In this study, a cadmium (Cd2+)-resistant bacterium, isolated from soil polluted with heavy metals, was characterized as Pseudomonas sp. 375 based on its biochemical characteristics and 16S rRNA gene. The minimum inhibitory concentration (MIC) of Cd2+ for strain 375 was 6 mM. We evaluated the effects of different parameters, such as initial pH, contact time, and initial Cd2+ concentration, on Cd2+ uptake. The data acquired using nonliving biomass were fitted to a Langmuir isotherm model; however, the Freundlich isotherm model showed better fit for data acquired using living biomass. The maximum biosorption capacities were 92.59 mg g-1 and 63.29 mg g-1 for living and nonliving cells, respectively. The kinetics of biosorption was described using a pseudo-second order kinetic model. The tightly bound Cd on the cell wall played a major role in Cd2+ adsorption for both biosorbents. SEM-EDX analysis also showed that Cd2+ was bound to the cell wall. FTIR spectral analysis showed that -CH2, -OH, -SO3, CO, N-H, C-N, phosphate, or sulfate functional groups were the main functional sites for the binding of Cd2+ ions. Effectively Cd2+ removal from Cd2+ contaminated water suggested Pseudomonas sp. 375 was an (a) inexpensive, effective, and promising biosorbent that can be used for bioremediation Cd2+-contaminated wastewater.


Assuntos
Cádmio/metabolismo , Pseudomonas/metabolismo , Poluentes do Solo/metabolismo , Adsorção , Biodegradação Ambiental , Biomassa , China , Poluentes Ambientais/análise , Concentração de Íons de Hidrogênio , Íons/análise , Cinética , Metais Pesados/análise , RNA Ribossômico 16S , Solo , Águas Residuárias/análise , Poluição da Água/análise
8.
Chemosphere ; 238: 124550, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31425868

RESUMO

Large volumes of contaminated water are produced via intentional and unintentional incidents, including terrorist attacks, natural disasters and accidental spills. Contaminated waters could contain harmful chemicals, which present management and disposal challenges. This study investigates three Advanced Oxidation Processes (AOPs) - UV/H2O2, O3/H2O2, and electrochemical oxidation using a boron-doped diamond (BDD) anode - to treat eleven contaminants including herbicides, pesticides, pharmaceuticals, and flame retardant compounds. To address treatment and toxicity concerns, this study focuses on the resulting microbial toxicity via Microtox® toxicity and Nitrification Inhibition tests. The results suggest four functional Microtox® toxicity categories upon AOP treatment, which are useful for streamlining AOP selection for specific applications. Except for one compound, the O3/H2O2 and UV/H2O2 AOPs achieved, within experimental error, 100% parent compound degradation during 2 h of treatment for all contaminants, as well as Microtox® toxicities that declined below 10% by the end of the treatment. In addition, anodic oxidation with a BDD electrode exhibited slower degradation and some increases in Microtox® toxicity. Only one compound exhibited above 50% Nitrification Inhibition, indicating the robustness of activated sludge to many contaminated and AOP-treated waters. These results indicate that AOP pre-treatment can be a viable strategy to facilitate drain disposal of contaminated waters, but that eco-toxicity may remain a concern.


Assuntos
Reatores Biológicos , Diamante/química , Eletrodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Poluição da Água/análise , Boro/química , Herbicidas/análise , Herbicidas/química , Herbicidas/toxicidade , Peróxido de Hidrogênio/química , Oxirredução , Praguicidas/análise , Praguicidas/química , Praguicidas/toxicidade , Microbiologia da Água , Poluentes Químicos da Água/análise , Purificação da Água/métodos
9.
Chemosphere ; 239: 124774, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31521937

RESUMO

Acid mine drainage represents an extreme type of water pollution. The environments develop especial hydrochemical and ecological characteristics, such as high concentrations of acidity and low biodiversity, with dominance of acidophilic organisms. Ecological criteria are assuming increasing relevance for assessing water quality, including in acid mine drainage-affected systems. Photosynthetic pigments, like chlorophyll, could be considered in this context as they are generally used to estimate phytoplankton biomass. The present work was focused on acid mine drainage and their relationships with chlorophyll a. It was developed in the historic mine of São Domingos (Iberian Pyrite Belt, SW Europe). The methodological approach comprised two sampling campaigns (October and February) to represent seasonal behaviour. The diversity of hydrological conditions was also considered through sampling sites established in the pit lake, acidic lagoons and affected stream. Hydrochemistry and chlorophyll a were analysed. The obtained results revealed very low pH values, with a minimum of 2.1. In general, hydrochemistry indicates higher concentrations of pollutants in summer. One of the sampling point, located in an acidic lagoon, stood out by highest concentrations, presenting maximum of sulfate (6564 mg/L), As (6.26 mg/L), and metals like Al (675 mg/L), Cd (1,30 mg/L), Zn (199 mg/L). These highest concentrations coincided with the maximum concentration of chlorophyll a (113 µg/L). The results suggested that the more contaminated the environment, more chlorophyll a was produced. Factor analyses emphasised the relationships between acid drainage properties and the photosynthetic activity, indicating a strong pH dependency of chlorophyll a production.


Assuntos
Clorofila A/análise , Mineração , Poluição da Água/análise , Biomassa , Monitoramento Ambiental , Europa (Continente) , Lagos/química , Metais/análise , Feofitinas/análise , Fotossíntese , Fitoplâncton , Rios/química , Estações do Ano , Sulfatos/análise , Poluentes Químicos da Água/análise , Qualidade da Água
10.
Sci Total Environ ; 699: 134301, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31525544

RESUMO

The concentration, source and composition of dissolved organic matter (DOM) in aquatic ecosystems are associated with land use and hydrological connectivity between terrestrial and aquatic systems. However, direct evidence of the effects of rainfall and land use on the variability of DOM in aquatic ecosystems is very limited. In this study, chromophoric DOM (CDOM) absorption and fluorescence spectroscopy were used to elucidate how rainfall and land use affect the variability of CDOM in the watershed of Lake Tianmu, a key drinking water reservoir in the Yangtze River Delta. The mean values of the fluorescence intensity (Fmax) of parallel factor analysis-derived humic-like components (C1, C3, C6) and tryptophan-like components C5 were higher in the southeastern inflowing river mouths than those downstream of the lake outlet regions. The upstream tributaries were mainly dominated by humic-like materials, while the lake was mainly dominated by protein-like materials. The Fmax values of four humic-like components and two tryptophan-like components all increased significantly as the %woodland decreased, but %anthropogenic land use (%cropland+%urban construction area) increased. The Fmax of the humic-like components at the inflowing tributaries and the lake increased with increasing rainfall during storm events, and the value was especially pronounced at the inflowing river mouths. We concluded that land use and hydrological conditions play an important role in influencing the CDOM source and optical composition, and these findings provide insights for the understanding of aquatic ecosystem metabolism and reservoir water quality management.


Assuntos
Água Potável/química , Monitoramento Ambiental/métodos , Poluição da Água/análise , China , Ecossistema , Análise Fatorial , Fluorescência , Lagos/química , Chuva , Rios , Estações do Ano , Espectrometria de Fluorescência , Poluição da Água/estatística & dados numéricos , Qualidade da Água
11.
Huan Jing Ke Xue ; 41(1): 304-312, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854931

RESUMO

In order to deal with low dissolved oxygen black odor water body of Guangdong-Hong Kong-Macao Greater Bay Area, the nitrogen metabolic capacity of ammoniated bacteria, nitrifying bacteria and denitrifying bacteria under low dissolved oxygen concentration was studied, and the relationship between denitrification efficiency and nitrogen conversion of different bacteria was clarified, which provided theoretical basis for the treatment of black odor water of Guangdong-Hong Kong-Macao Greater Bay Area. Nitrogen conversion characteristics of ammoniated bacteria (Staphylococcus sp. Ay), nitrifying bacteria (Microbacterium sp. Xw), and denitrifying bacteria (Arthrobacter sp. Fy) in simulated wastewater were detected by different concentration of bacteria and different concentration of substrates. The nitrogen metabolism of Ay, Xw and Fy in black odor water at the same concentration under low dissolved oxygen condition and the characteristics of nitrogen metabolism in different concentrations of black odor water were studied. The results showed that the bacterial concentration of Ay bacterium agent increased three times, but the ammoniation efficiency did not multiply. It indicated that increasing the concentration of ammoniated bacterium was not the best way to increase the ammoniation rate. Xw bacteria have a significant effect on the change of nitrate concentration. At 60 h, the nitrate concentration was increased 180% at low bacterial concentration, was 231% at a high bacterial concentration. Fy denitrification efficiency was high, that nitrate nitrogen can be removed quickly at lower concentration. Appropriate increase of total nitrogen concentration can increase the ammoniation efficiency of Ay microbial agent, but too high would inhibit the nitrogen metabolism efficiency of Ay microbial agent. The concentration of nitrate nitrogen of Xw bacterium reagent was increased (3736%) when the total nitrogen was 25 mg·L-1. The Fy microbial agent has no obvious effect on ammonia nitrogen removal. When the total nitrogen concentration was 25 mg·L-1, the removal rate of nitrate by Fy bacterium was the best. Overall, the results showed that the concentration of ammoniated bacteria and denitrifying bacteria could meet the need of nitrogen metabolism, and the nitrifying bacteria could increase the nitrate nitrogen synthesis rate with the increase of the concentration of nitrifying bacteria. In a certain range, increasing the concentration of substrate could increase the efficiency of nitrogen metabolism of bacterial agents, and excessive concentration would inhibit the effect of nitrogen metabolism. The study provides data support for the problem of black odor water in Guangdong-Hong Kong-Macao Greater Bay Area.


Assuntos
Bactérias/metabolismo , Desnitrificação , Nitrogênio/metabolismo , Odorantes , Oxigênio , Poluição da Água , Baías , Hong Kong , Nitrificação , Água do Mar , Águas Residuárias , Purificação da Água
12.
J Environ Manage ; 253: 109689, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654929

RESUMO

Sponge City concept is emerging as a new kind of integrated urban water systems, which aims to address urban water problems. However, its implementation has encountered a variety of challenges. The lack of an integrated comprehensive model to assist Sponge City planning, implementation and life cycle assessment is one of the most challenging factors. This review briefly analyses the opportunity of existing urban water management models and discusses the limitation of recent studies in the application of current integrated models for Sponge City implementation. Furthermore, it proposes a new Sponge City model framework by integrating four main sub-models including MIKE-URBAN, LCA, W045-BEST, and MCA in which environmental, social, and economic aspects of Sponge City infrastructure options are simulated. The new structure of Sponge City model that includes the sub-model layer, input layer, module layer, output layer, and programing language layer is also illustrated. Therefore, the proposed model could be applied to optimize different Sponge City practices by not only assessing the drainage capacity of stormwater infrastructure but also pays attention to multi-criteria analysis of urban water system (including the possibility of assessing Sponge City ecosystem services for urban areas and watershed areas) as well. Balancing between simplification and innovation of integrated models, increasing the efficiency of spatial data sharing systems, defining the acceptability of model complexity level and improving the corporation of multiple stakeholders emphasizing on possible future directions of a proper Sponge City design and construction model.


Assuntos
Planejamento de Cidades , Ecossistema , Cidades , Poluição da Água
13.
Chemosphere ; 238: 124623, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545212

RESUMO

The Indo-Gangetic alluvium is prime region for intensive agricultural. In some areas of this region, groundwater is now becoming progressively polluted by contamination with poisonous substances like arsenic. Intensive irrigation with arsenic contaminated ground water in dry spell results in the formation of As(III) which is more toxic. Thus groundwater quality assessment of Gangetic basin has become essential for its safer use. Therefore we under took study on the spatial variability of arsenic by collecting georeferred groundwater samples on grid basis from various water sources like dug well, bore and hand pumps covering the river bank region of Ganga basin. Water quality was investigated through determination pH, EC, TDS, salinity, Na, K, Ca, Mg, SAR, SSP, CO3, HCO3, RSC, Cl, As, Fe, Zn, Mn and Cu, etc. Results pointed severe As contamination in ground water of three sites of the study area. ARC GIS software is now able to process maps along with tabular data and compare them well, to provide the spatial visualization of information and using this tool, the Geographical Information System (GIS) of arsenic was developed. It was noticed from spatial maps that concentration of arsenic was more near the meandering points of Ganga.


Assuntos
Arsênico/análise , Monitoramento Ambiental/métodos , Água Subterrânea/química , Rios/química , Poluentes Químicos da Água/análise , Geografia , Humanos , Índia , Íons , Medição de Risco , Salinidade , Poluição da Água/análise , Qualidade da Água , Abastecimento de Água/normas
14.
Water Res ; 171: 115392, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31865126

RESUMO

The last decades have seen the development of several source tracking (ST) markers to determine the source of pollution in water, but none of them show 100% specificity and sensitivity. Thus, a combination of several markers might provide a more accurate classification. In this study Ichnaea® software was improved to generate predictive models, taking into account ST marker decay rates and dilution factors to reflect the complexity of ecosystems. A total of 106 samples from 4 sources were collected in 5 European regions and 30 faecal indicators and ST markers were evaluated, including E. coli, enterococci, clostridia, bifidobacteria, somatic coliphages, host-specific bacteria, human viruses, host mitochondrial DNA, host-specific bacteriophages and artificial sweeteners. Models based on linear discriminant analysis (LDA) able to distinguish between human and non-human faecal pollution and identify faecal pollution of several origins were developed and tested with 36 additional laboratory-made samples. Almost all the ST markers showed the potential to correctly target their host in the 5 areas, although some were equivalent and redundant. The LDA-based models developed with fresh faecal samples were able to differentiate between human and non-human pollution with 98.1% accuracy in leave-one-out cross-validation (LOOCV) when using 2 molecular human ST markers (HF183 and HMBif), whereas 3 variables resulted in 100% correct classification. With 5 variables the model correctly classified all the fresh faecal samples from 4 different sources. Ichnaea® is a machine-learning software developed to improve the classification of the faecal pollution source in water, including in complex samples. In this project the models were developed using samples from a broad geographical area, but they can be tailored to determine the source of faecal pollution for any user.


Assuntos
Microbiologia da Água , Água , Ecossistema , Monitoramento Ambiental , Escherichia coli , Fezes , Humanos , Poluição da Água
15.
Water Res ; 171: 115342, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31841955

RESUMO

Volunteer monitoring in the Hudson River watershed since 2012 has identified that the Wallkill River and Rondout Creek tributary complex have elevated concentrations of the fecal indicator bacteria, enterococci. Concentrations of enterococci do not provide insight into the sources of pollution and are imperfect indicators of health risks. In 2017, the regular monthly volunteer monitoring campaign for culturable enterococci at 24 sites on the Wallkill and Rondout expanded to include: (1) culturable measurements of E. coli and quantification of E. coli and Enterococcus specific markers vis nanoscale qPCR, (2) microbial source tracking (MST) assays (avian, human, bovine, and equine) via real time PCR and nanoscale qPCR, and 3) quantification of 12 gastrointestinal pathogens including viruses, bacteria, and protozoa via nanoscale qPCR. Three human associated MST markers (HumM2, HF183, and B. theta) corroborated that human pollution was present in Rondout Creek and widespread in the Wallkill River. The presence of B. theta was associated with increased concentrations of culturable E. coli. Genes for adenovirus 40 and 41 conserved region, rotavirus A NSP3, E. coli eae and stx1, and Giardia lamblia 18S rRNA were detected in >45% of samples. Abundance of rotavirus A NSP3 genes was significantly correlated to the bovine marker gene, CowM3, though wild bird sources cannot be ruled out. This is the first study to investigate potential fecal pollution sources and pathogen concentrations in Hudson tributaries during the months of peak recreational use.


Assuntos
Rios , Microbiologia da Água , Animais , Bactérias , Bovinos , Monitoramento Ambiental , Escherichia coli , Fezes , Cavalos , Humanos , Poluição da Água
16.
Environ Monit Assess ; 191(12): 781, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31786659

RESUMO

Prolonged consumption of fluoride-contaminated water poses health problems like dental and skeletal fluorosis in many parts of the world including India. In regions with acute water scarcity, it demands immediate intervention like de-fluoridation of water before consumption. In the current study, fluoride-resistant bacteria were isolated from fluoride-contaminated groundwater and soil samples collected from Dungarpur district, India, for their potential use in defluoridation. Out of a total of 53 bacterial isolates that were recovered and screened for fluoride resistance, three highly fluoride-resistant isolates DWC1, DWC2 and DWB5, resistant to up to 9200 mg L-1, 7200 mg L-1 and 5200 mg L-1 fluoride respectively, were characterized and identified as Aeromonas sp., Brevibacterium sp. and Paenibacillus sp. respectively. The fluoride removal capacity of isolates DWC1, DWC2, DWB5 and a consortium of all the three isolates was found to be 68.7%, 73.4%, 76.7 % and 70.1% respectively on nutrient broth supplemented with NaF (2000 mg L-1) after 8 days of incubation. Defluoridation conditions for the strain showing the best result (Paenibacillus sp.) were optimized for real fluoride-rich water collected from Ajmer District, India, using the Taguchi design of experiment. A defluoridation of up to 73.3% was observed at 40 °C temperature and pH 8 with inoculum: water ratio of 2:1 after 8 days of incubation. To the best of our knowledge, the defluoridation capacity of Paenibacillus sp. is the highest reported in literature to date for real water samples and could be investigated in further detail for commercial application.


Assuntos
Bactérias , Fluoretos , Água Doce , Purificação da Água , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Farmacorresistência Bacteriana , Fluoretos/análise , Fluoretos/metabolismo , Fluoretos/farmacologia , Água Doce/química , Água Doce/microbiologia , Índia , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Poluição da Água , Purificação da Água/métodos
17.
Georgian Med News ; (295): 171-177, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31804222

RESUMO

In modern conditions, the use and protection of water is an extremely complex problem. The environmental situation of water resources is relevant for all water basins in Ukraine, since most of the surface and groundwater in Ukraine are polluted. The aim of the research was to study the regulatory normatively-legal base of sanitary, ecolocal, water and urban planning legislation in the field of sanitary protection of water objects and establishing its compliance with the requirements of the European Union Directives with the development of measures to resolve issues of concern. Ukraine's international obligations are enshrined in more than 40 global and regional international acts relating to the sanitary protection and use of water resources.The main requirements of the EU Directive (2008/56/EC, 98/83/EC, 2008/105/EC, 2003/35/EC, 2003/4/EC, 2001/42/EC, 2011/92/EC) are already taken into account new laws in force and domestic regulatory documents. However, the regulatory framework of the legislation of Ukraine in the field of sanitary protection of water objects needs to be improved in terms of focusing on new mechanisms of economic regulation, decentralization of power, the introduction of effective monitoring of the ecological status of the Black and Azov Seas, and the implementation of the requirements of the EU Directives: 2006/7/ЄС, 2007/60/ЄС 91/271/ЄЕС, 91/676/ЄЕС and Regulation No648/2004. In order to improve the sanitary-epidemiological state of water resources in Ukraine, their rational use and protection, it is proposed to carry out: an effective state and legal policy in the field of sanitary protection of waters, focused on: the effective implementation of water, environmental, urban planning legislation of Ukraine; optimal coordination of architectural and planning, water-ecological, sanitary-epidemiological aspects and social interests; priority of drinking water supply and water protection measures; implementation of international treaties with a view to the proper legal, sanitary and epidemiological regime of transboundary water objects; implementation of European standards for the quantitative and qualitative status of waters; the formation of an ecological, sanitary and epidemiological worldview among the population.


Assuntos
Água Subterrânea , Higiene , Poluição da Água , União Europeia , Controle Social Formal , Ucrânia , Poluição da Água/prevenção & controle , Abastecimento de Água
18.
Huan Jing Ke Xue ; 40(7): 3078-3088, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854705

RESUMO

To investigate the hydrochemical variation of karstic groundwaters in a vertically zoned climate region affected by human activity, Shuifang Spring and Bitan Spring in the Jinfo Mountain area of Chongqing were selected as a study site. Based on the differences between the natural state and intensity of human activity of these two springs, their hydrogeochemical characteristics and the controlling factors on karstic groundwaters were analyzed by means of independent sample t tests, the Gibbs graphic method, principle component analysis (PCA), and geochemical susceptivity analysis. The results show that differences in karst development in the vertical climatic zone leads to higher total ion concentrations in Bitan Spring than in Shuifang Spring. The hydrochemical types of Shuifang Spring and Bitan Spring are HCO3-Ca and HCO3-Ca·Mg, respectively, which reflect the lithology of their different elevations. Carbonate rock dissolution is the main source of Ca2+, Mg2+, and HCO3- in karstic groundwaters. Hotel sewage discharge supplies SO42-, NO3-, PO43-, K+, and Na+ in Shuifang Spring, which peaked in winter and summer, while hydrochemical parameters of Bitan Spring changed smoothly throughout the year. The water quality of Bitan Spring is better than Shuifang Spring (Shuifang Spring water is classified as Class Ⅳ). PCA shows that the water-rock interaction was the first controlling factor. Hotel sewage discharge and ions from precipitation had important effects on Shuifang Spring and Bitan Spring, respectively. In addition, the effects of soil erosion and leaching caused by precipitation also impact on the water quality of two springs to some extent. The geochemical susceptibility of Shuifang Spring was greater than that of Bitan Spring; therefore, corresponding measures should be formulated according to the characteristics of these differently elevated karst systems when exploiting groundwater resources. This is especially the case for the treatment of hotel sewage.


Assuntos
Monitoramento Ambiental , Água Subterrânea/análise , Nascentes Naturais/análise , Poluição da Água/análise , Qualidade da Água , China , Atividades Humanas , Humanos , Esgotos
19.
Water Sci Technol ; 80(7): 1238-1248, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31850875

RESUMO

The frequent occurrence of sudden water pollution accidents has become a major threat to water environment safety. Although most researches have focused on constructing a pollutant source identification model and risk assessment methods for dealing with sudden water pollution accidents, a real-time, effective emergency measure for controlling pollutant diffusion, isolating and removing the pollutant, aiming at sudden water pollution accidents, has not been emphasized. Therefore, in this paper, a novel emergency approach of soft isolation was investigated to control pollution diffusion and decrease damage as soon as the accident occurred. In stage 1, the feature of pollution diffusion regarding a sudden water accident was predicted through a water quality model using computational fluid dynamics (CFD). Then, a design scheme of soft isolation was constructed in stage 2 to isolate the polluted zone and attention was paid to optimizing the parameters of soft isolation. Ultimately, the mathematical model of complete purification was formulated in stage 3 to remove the pollution from the impacted zone. The results indicated that the emergency measure of soft isolation could have significant potential to control and isolate pollution occurring in a sudden water pollution accident in the future.


Assuntos
Poluentes Químicos da Água , Poluição da Água , Acidentes , China , Modelos Teóricos , Qualidade da Água
20.
Environ Monit Assess ; 191(12): 776, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31776793

RESUMO

In order to fill a gap in the monitoring of water quality in Brazil, the objective of this study was to propose a methodology to support the allocation of water quality monitoring stations in river basins. To achieve this goal, eight criteria were selected and weighted according to their degree of importance. It was taken into account the opinion of water resources management experts. In addition, a decision support system was designed so that the methodology could be used in the allocation of water quality monitoring stations by researchers and management bodies of water resources, to be fully implemented in geographic information system environment. In order to demonstrate the potential of the proposed methodology, which can be used in places that have or not existing monitoring networks, it has been applied in the Minas Gerais portion of the Doce river basin. Because the area already has a monitoring network with 65 stations in operation under the responsibility of the Minas Gerais Water Management Institute (IGAM), an expansion of the network was suggested and a simulation of a scenario was performed considering that the study area did not have an established network. The results of the analyses consisted of maps of suitability, indicating the locations with greater and lesser suitability for the establishment of the stations. With the application of the methodology, seven new sites were proposed so that the study area had the density recommended by the National Water Agency (ANA), and it was verified that the Caratinga River Water Resources Management Unit (UGRH5 Caratinga) has the most deficiency of stations among the six units evaluated in the Minas Gerais portion of the Doce river basin. In the simulated scenario considering the non-existence of a network, the adequacy map obtained was compared with the existing monitoring network and it was possible to classify the stations according to the purpose for which they were established, such as monitoring environments under anthropic activities or establishing benchmarks for the water bodies. Overall, the proposed methodology proved itself robust, and although the results were specific to one basin, the criteria and decision support system used are fully applicable to other areas of study.


Assuntos
Técnicas de Apoio para a Decisão , Monitoramento Ambiental , Alocação de Recursos , Rios , Qualidade da Água , Brasil , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica , Poluição da Água/análise , Qualidade da Água/normas
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