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1.
J UOEH ; 42(3): 237-249, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879188

RESUMO

Access to water and sanitation remain a challenge in many developing countries, especially in pro-poor urban informal settlements where socioeconomic livelihoods are generally low. The aim of this study was to characterise the water and sanitation facilities in the informal settlements of Kisumu City and to evaluate their effect on community hygiene and health. The study focussed on the five urban informal settlements of Nyalenda A, Nyalenda B, Manyatta A, Manyatta B and Obunga, and the three Peri-urban informal settlements of Kogony, Usoma and Otonglo. Using descriptive techniques, the researcher surveyed 114 water sources and all sanitation facilities within 0-15 m and 15-30 m radii of the water sources. The findings revealed dominance of shallow wells and traditional pit latrines as the primary water sources and sanitation facilities, respectively. Out of the water sources studied, 87.7% (100) were shallow wells (mean depth 1.5 m), 9.6% (11) springs and 2.6% (3) boreholes. Most of these shallow wells (83%) were within the urban informal settlements where uses range from washing and cleaning, cooking, and even drinking (13.5%), despite the majority being unprotected. The analysis of the density of sanitation facilities near the water points showed that 32.3% existed within a 15 m radius of the nearest water sources, in violation of the recommended safe distance of 30 m. With an increased density of toilets near critical water sources and other sanitary practices, public health is highly compromised.


Assuntos
Planejamento em Saúde , Pobreza , Saneamento , Classe Social , Toaletes , Saúde da População Urbana , Abastecimento de Água , Humanos , Quênia
2.
Environ Monit Assess ; 192(10): 631, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32902699

RESUMO

In recent years, it has been difficult to establish a supply-demand balance between urban growth, increasing population, and existing water resources in many countries. In this study, the Bodrum Peninsula, which is an important tourism center for Turkey, was examined in terms of the relationship between the urban growth of the peninsula, population projections, the need for drinking and potable water, and the availability of the existing water resources. Using the Geographic Information System, it has been determined that the urban growth of the peninsula increased by 11.36% between 1985 and 2010. Urban growth is mostly concentrated in the coastal areas where 2 houses are densely built. The population is expected to increase approximately six times between 2010 and 2060. The amount of drinking and potable water required according to the population projection is 12.38, 26.50, 69.12, and 109.50 hm3/year for 2010, 2030, 2050, and 2060 respectively. The existing water resources of the peninsula will be able to meet the requirements until 2030. In order to meet the water needs of the peninsula until 2055, the Bozalan and Gökçeler dams located nearby as well as the Namnam dam located at mid-range to the peninsular should be built. It is not possible to meet the water needs of the peninsula in 2060 with just the near and medium distance water resources. However, by supplying water from the Akköprü dam located at a further distance, it is possible that 2060 water needs can be met.


Assuntos
Crescimento Demográfico , Recursos Hídricos , Conservação dos Recursos Naturais , Monitoramento Ambiental , Turquia , População Urbana , Abastecimento de Água
3.
Water Sci Technol ; 82(1): 81-96, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32910794

RESUMO

Allocating effluent of wastewater treatment plants to users of economic sectors and satisfying their requirements has created a challenging debate and a need for prioritization. This study assesses the importance of sectors that utilize treated wastewater (TWW) using risk and social acceptability indexes based on expert-oriented approaches. Considered sectors are agriculture, industry, urban green space and natural resources and the study area is located in Iran, around the Isfahan North Wastewater Treatment Plant. The risk index is calculated using Frank and Morgan model and consequently TWW use in the industrial sector is less dangerous than other sectors. Moreover, the social acceptability index, which was determined using Mamdani fuzzy inference set, indicates higher acceptability of TWW use in natural resources sector compared with other sectors. By constructing the conceptual model, generating the decision matrix and using the results of gray relational analysis decision-making model for the four sectors, the allocation priorities of TWW became industry, natural resource, green space, and agriculture respectively. It is suggested that Water and Wastewater Company grant permission for TWW use to water-consuming industries and man-made forests development, which result in increasing employment, reduction of harmful effects of dust, and water consumption decrease.


Assuntos
Agricultura , Águas Residuárias , Conservação dos Recursos Naturais , Irã (Geográfico) , Abastecimento de Água
4.
Wei Sheng Yan Jiu ; 49(4): 540-545, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32928345

RESUMO

OBJECTIVE: To understand the rural sanitary conditions in different geographical areas of Shaanxi Province. METHODS: According to the stratified random sampling method, 30 agriculture-related counties were selected(The central area includes 13 counties in Xi'an, Tongchuan, Weinan, Xianyang and Baoji cities. The southern area includes 10 counties in Hanzhong, Ankang, Shangluo cities. The northern area includes 7 counties in Yulin, Yan'an cities. ). Five townships were selected randomly in each county(excluding Chengguan Town), and 4 administrative villages were selected randomly in each township as survey villages, which were collected the soil samples for testing lead, cadmium and chromium in each subject village, and 5 households were randomly selected in each villages as survey households. The data was obtained through data reading, interviews, on-site observations, and laboratory testing, etc. The detection of soil lead and cadmium was carried out according to the Measurement of Soil Quality Lead and Cadmium by Graphite Furnace Atomic Absorption Spectrophotometry(GB/T 17141-1997), and the detection of chromium was carried out according to the Determination of Total Chromium in Soil by Flame Atomic Absorption Spectrometry(HJ 491). The data was statistically analyzed and evaluated according to the central, southern and northern regions. RESULTS: The population coverage of rural centralized water supply in the three regions(central、southern and northern area) was 92. 86%, 75. 49% and 70. 41%, respectively. The penetration rate of sanitary toilets was 28. 18%, 45. 38% and 9. 90%, respectively. The proportion of villages where domestic garbage was randomly stacked was 0. 38%, 4. 00% and 32. 86%, respectively. The proportion of villages where domestic sewage was randomly discharged was 30. 38%, 40. 00% and 60. 00%, respectively. The heavy metals exceeding the standard in the soil were mainly cadmium. The over-standard rates were 4. 62%, 21. 50% and 0. 71%, respectively. The three regional differences of the above result were statistically significant(χ~2=57 676. 74, 18 143. 94, 124. 86, 33. 15 and 54. 12, P<0. 01). CONCLUSION: There was still some decentralized water supply population in the province. The coverage rate of the centralized water supply population and the proportion of drinking water after complete treatment projects were both higher in the central area than in the southern area and northern area. Sanitation toilets have a low penetration rate in the province, which was higher in the southern area than in the central area and the northern area. The domestic garbage was randomly discarded, and domestic sewage was randomly discharged, which was more in the northern area than in the central area and the southern area. Soil cadmium pollution was relatively heavy, mainly in the southern area.


Assuntos
Água Potável , Metais Pesados , Cidades , Humanos , Saneamento , Abastecimento de Água
5.
Infect Dis Poverty ; 9(1): 124, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867851

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) was confirmed in Brazil in February 2020. Since then, the disease has spread throughout the country, reaching the poorest areas. This study analyzes the relationship between COVID-19 and the population's living conditions. We aimed to identify social determinants related to the incidence, mortality, and case fatality rate of COVID-19 in Brazil, in 2020. METHODS: This is an ecological study evaluating the relationship between COVID-19 incidence, mortality, and case fatality rates and 49 social indicators of human development and social vulnerability. For the analysis, bivariate spatial correlation and multivariate and spatial regression models (spatial lag model and spatial error models) were used, considering a 95% confidence interval and a significance level of 5%. RESULTS: A total of 44.8% of municipalities registered confirmed cases of COVID-19 and 14.7% had deaths. We observed that 56.2% of municipalities with confirmed cases had very low human development (COVID-19 incidence rate: 59.00/100 000; mortality rate: 36.75/1 000 000), and 52.8% had very high vulnerability (COVID-19 incidence rate: 41.68/100 000; mortality rate: 27.46/1 000 000). The regression model showed 17 indicators associated with transmission of COVID-19 in Brazil. CONCLUSIONS: Although COVID-19 first arrived in the most developed and least vulnerable municipalities in Brazil, it has already reached locations that are farther from large urban centers, whose populations are exposed to a context of intense social vulnerability. Based on these findings, it is necessary to adopt measures that take local social aspects into account in order to contain the pandemic.


Assuntos
Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Determinantes Sociais da Saúde , Adolescente , Brasil/epidemiologia , Criança , Pré-Escolar , Intervalos de Confiança , Infecções por Coronavirus/mortalidade , Educação , Emprego , Humanos , Incidência , Renda , Longevidade , Análise Multivariada , Pandemias , Pneumonia Viral/mortalidade , Pobreza , Análise de Regressão , Saneamento , Esgotos , Condições Sociais , Análise Espacial , Abastecimento de Água/normas , Adulto Jovem
6.
Science ; 369(6507): 1058, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32855327
7.
Braz J Microbiol ; 51(3): 1109-1115, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32809115

RESUMO

COVID-19 has killed more than 500,000 people worldwide and more than 60,000 in Brazil. Since there are no specific drugs or vaccines, the available tools against COVID-19 are preventive, such as the use of personal protective equipment, social distancing, lockdowns, and mass testing. Such measures are hindered in Brazil due to a restrict budget, low educational level of the population, and misleading attitudes from the federal authorities. Predictions for COVID-19 are of pivotal importance to subsidize and mobilize health authorities' efforts in applying the necessary preventive strategies. The Weibull distribution was used to model the forecast prediction of COVID-19, in four scenarios, based on the curve of daily new deaths as a function of time. The date in which the number of daily new deaths will fall below the rate of 3 deaths per million - the average level in which some countries start to relax the stay-at-home measures - was estimated. If the daily new deaths curve was bending today (i.e., about 1250 deaths per day), the predicted date would be on July 5. Forecast predictions allowed the estimation of overall death toll at the end of the outbreak. Our results suggest that each additional day that lasts to bend the daily new deaths curve may correspond to additional 1685 deaths at the end of COVID-19 outbreak in Brazil (R2 = 0.9890). Predictions of the outbreak can be used to guide Brazilian health authorities in the decision-making to properly fight COVID-19 pandemic.


Assuntos
Infecções por Coronavirus/epidemiologia , Previsões/métodos , Pneumonia Viral/epidemiologia , Algoritmos , Brasil/epidemiologia , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/prevenção & controle , Detergentes/provisão & distribução , Educação/estatística & dados numéricos , Humanos , Análise dos Mínimos Quadrados , Dinâmica não Linear , Pandemias/prevenção & controle , Pneumonia Viral/mortalidade , Pneumonia Viral/prevenção & controle , Política , Densidade Demográfica , Pobreza , Fatores Socioeconômicos , Estatística como Assunto , Fatores de Tempo , Abastecimento de Água/normas
8.
Environ Monit Assess ; 192(9): 607, 2020 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-32860540

RESUMO

The present study aimed to propose a water quality index (WQI) for the Federal District, Brazil, as a management tool for water resources used in irrigation. Irrigated agriculture is a sector that has been growing in the region, with a consequent demand for quality water. One strategy for assessing water quality in rural areas is to adopt monitoring programs, which generate a large amount of data that often needs to be synthesized. The use of indexes is a way of organizing data in a synthetic and easy to understand format. Although initially formulated to assess the quality of drinking water, it is believed that a similar logic can easily be applied to assess the quality of irrigation water. Studies that evaluate the quality of water for irrigation are very common in arid or semi-arid regions, due to the problems of saline water in the soil and crops. On the other hand, the microbiological approach to water is poorly investigated, since contamination of crops can pose a risk to food security. In this work, three water bodies were selected in rural areas due to their preponderant use: irrigation. The monitoring occurred between May 2012 and April 2013 in 9 sampling points. For each sample collected, 22 physical, chemical, and biological parameters were established. Principal component analysis (PCA) was used in the evaluation and selection of water quality variables to compose the WQI. From PCA, it was possible to reduce the number of parameters from 16 to 6 main ones that reflect the water resources characteristics in the region, which were pH, electrical conductivity, total hardness, sodium absorption ratio, nitrate, and Escherichia coli. Of the five classes proposed for WQI, two points were classified as "very good." The other sample points were classified as "good" and "average" for the irrigation practice. The adapted WQI proved to be a good tool in the management of the water quality of the three rivers, and it can be easily used to assess the quality of water for irrigation in the region.


Assuntos
Poluentes Químicos da Água/análise , Qualidade da Água , Irrigação Agrícola , Brasil , Monitoramento Ambiental , Abastecimento de Água
9.
Sci Total Environ ; 744: 140674, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32755770

RESUMO

Faecally-contaminated drinking water is a risk to human health, with the greatest risks to those living in developing countries. UN Sustainable Development Goal 6 aims to address this issue. Tryptophan-like fluorescence (TLF) shows potential as a rapid method for detecting microbial contamination in drinking water, which could reduce the spread of waterborne diseases. This study is the first to investigate the effectiveness of TLF for a large-scale survey using a randomised, spot-sampling approach. The large-scale survey took place in Malawi, sub-Saharan Africa, in the dry season (n = 183). A subset of sources were revisited at the end of the following wet season (n = 41). The effectiveness of TLF was assessed by comparing TLF results to thermotolerant coliforms (TTC), humic-like fluorescence (HLF), inorganic hydrochemical data and sanitary risk scores. The most prominent differences in microbial water quality were observed between source types, with little variation between districts and seasons. TLF, TTCs, turbidity and sanitary risk scores were all elevated at alternative sources (shallow wells and tap stands) compared to hand-pumped boreholes. In the dry season, 18% of hand-pumped boreholes showed TTC contamination, which increase to 21% in the wet season. Groundwater recharge processes are likely responsible for seasonal variability of inorganic hydrochemistry at hand-pumped boreholes. TLF was able to distinguish no and low WHO risk classes (TTC 0-9 cfu/100 mL) from medium, high and very high risk classes (TTC 10 - >1000 cfu/100 mL). TLF failed to distinguish between no and low risk classes, which limits the use of TLF for assessing water quality to drinking water standards. This dataset indicates that HLF may raise baseline TLF for samples with low TLF values, increasing false positives. Therefore, TLF is better suited as a rapid high-level water quality screening tool to assess moderate and high levels of faecal contamination.


Assuntos
Água Potável , Monitoramento Ambiental , Humanos , Malaui , Estações do Ano , Inquéritos e Questionários , Triptofano , Microbiologia da Água , Qualidade da Água , Abastecimento de Água
10.
An Acad Bras Cienc ; 92(3): e20181107, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785462

RESUMO

This paper aimed at to evaluate the qualitative effects of climatic seasonality in a subtropical lagoon, using Discriminant Analysis, as well to identify the most sensitive and responsible parameters for these changes. The Mirim Lagoon watershed is one of the main transboundary basins in South America and is of great economic importance for the region because its waters are used for irrigation of rice fields and for the potable water supply to populations close to it, in this way, these uses may affect the quality of the basin waters. The data used in the study were provided and collected by the Mirim Lagoon Development Agency. Water quality parameters were selected in a five-year database and submitted to statistical tests that demonstrated their distinctions throughout the climatic seasons. The results showed that the parameters temperature, pH, dissolved oxygen, biochemical oxygen demand, total nitrogen and total phosphorus differ statically between the four climatic seasons. Were also identified four discriminative parameters between the seasons, being them dissolved oxygen, biochemical oxygen demand, total nitrogen and total phosphorus. In this way, it can be concluded that the seasonality mainly affects anthropogenic pollution sources such as agricultural activities and domestic discharges.


Assuntos
Monitoramento Ambiental , Qualidade da Água , Brasil , Rios , Estações do Ano , Abastecimento de Água
11.
Environ Monit Assess ; 192(8): 558, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32740690

RESUMO

The objective of this study is to propose and apply a novel approach to develop a drinking water quality index that enables water managers to routinely identify the vulnerabilities in a distribution system (DS) while taking into account the priorities of water managers and operators. Here, we propose an innovative approach based on the participation of eight researchers and water managers. The input from these participants was included through a combination of the Delphi and MACBETH (Measuring Attractiveness by a Categorical-Based Evaluation Technique) methods, which were applied to an index developed using fuzzy logic. The index was then validated by conducting sensitivity and comparative analyses on a database from field sampling campaigns conducted in various small municipal DSs in two Canadian provinces: Quebec and Newfoundland and Labrador. Finally, the drinking water quality index was applied to a database of the DS in Quebec City, Canada. Sensitivity and comparative analyses revealed that the developed index could allow for the characterization of water sample quality and could prove useful for prioritizing interventions in the DS. The index was also useful for representing the spatial variability of water quality, and provided nuanced information about water quality, especially when the water quality parameter values complied with guidelines and regulations. These results provide a transferable and integrated approach for developing customized drinking water quality indices. This study will help pave the way for water quality managers to better prevent episodes of possible water quality deterioration.


Assuntos
Água Potável , Qualidade da Água , Canadá , Monitoramento Ambiental , Terra Nova e Labrador , Quebeque , Abastecimento de Água
12.
Sci Total Environ ; 737: 140291, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783865

RESUMO

This paper presents information on the concentration of radioactivity and chemicals at 12 water stations that used groundwater as their raw water supply source. The groundwater's radioactivity was higher than the treated, tap, and surface water, but lower than the national and international recommendations. At five stations (41.7%), the gross alpha contents were higher than the levels advised by Vietnam's regulations, but met the WHO and IAEA's recommendations. The mean activity (Bq L-1) gross alpha, gross beta, Ra-224, Ra-226, and Ra-228 were 0.093 ± 0.012, 0.221 ± 0.020, 0.031 ± 0.004, 0.028 ± 0.004, and 0.035 ± 0.001, respectively. The contribution of Ra-226 to the gross alpha was in a range of 23%-60% (r = 0.91, p value <0.001), and the ratio of Ra-226/Ra-228 ranged from 0.49-1.06. For the treated and tap water, each age groups' annual committed effective dose was lower than the international regulations. The concentration of the total dissolved solids, sulfate, chloride, sodium, barium, and manganese met the national regulations. However, during the rainy season, the surface water in the area was affected by saltwater intrusion, with salinity up to 4.1‰. Discriminant analysis was applied to study the differences among the water groups. As a result, the treated and tap water were separated from the others.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos da Água/análise , Saúde Pública , Vietnã , Abastecimento de Água
13.
Sci Total Environ ; 737: 140296, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783866

RESUMO

Disinfection byproducts (DBPs) in drinking water is an issue in many countries. Many DBPs are possible or probable human carcinogens while few DBPs pose cyto- and genotoxic effects to the mammalian cells. The populations are likely to consume DBPs with drinking water throughout their lifetimes. A number of DBPs are regulated in many countries to protect humans. In this study, human exposure, risk and disability-adjusted life years (DALY) were predicted from DBPs in multiple water supply systems, including groundwater (GW), desalinated water (DW) and blend water (BW). The averages of lifetime excess cancer risks from GW, DW and BW were 4.15 × 10-6, 1.75 × 10-5 and 2.59 × 10-5 respectively. The populations in age groups of 0 - <2, 2-16 and >16 years contributed 25.4-25.7%, 28.6-29.6% and 45.0-45.7% to the total risks respectively. The DALY from GW, DW and BW were estimated to be 5.8, 27.0 and 39.9 years, respectively while the corresponding financial burdens were US$ 0.63, 2.93 and 4.34 million respectively. The findings are likely to assist in selecting the supply water sources to better control human exposure and risk from DBPs.


Assuntos
Desinfetantes/análise , Água Potável/análise , Poluentes Químicos da Água/análise , Purificação da Água , Animais , Desinfecção , Halogenação , Humanos , Anos de Vida Ajustados por Qualidade de Vida , Arábia Saudita , Abastecimento de Água
14.
Water Sci Technol ; 81(11): 2281-2290, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32784273

RESUMO

The history of water supply and wastewater engineering in Crete Island (Greece) dates back more than ca 4,500 years, since the early Bronze Ages. In the Minoan era, it was recognized that the removal of wastewater and storm-water were necessary for communal living. The early Minoan developments in wastewater and storm-water collection and removal are the cornerstones on which modern cities are built. The evolution of wastewater and storm-water management from prehistoric to modern times in Crete is examined briefly in this paper. Information on the current status and future strategies for wastewater and storm-water management is also presented.


Assuntos
Águas Residuárias , Água , Cidades , Grécia , Ilhas , Eliminação de Resíduos Líquidos , Abastecimento de Água
16.
J Environ Manage ; 270: 110807, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721292

RESUMO

To help minimize urban industrial water consumption and realize the goal of a water-saving society, this paper develops a method for the dynamic optimization of the input production factors in an urban industrial water supply model. A negative exponential curve describes the urban industrial water consumption per Yuan of urban industrial value added, the latter being described by a Gompertz curve. The product of the two describes the urban industrial water demand. The production function of urban industrial water supply is expressed by the fixed substitution proportional production function. Taking investment and labor input as control variables, the system goal is to balance of industrial water supply and demand. The time-varying model can not only solve the stable state problem for infinite time horizon, but also the transient problem for finite time horizon. Taking Jiangsu province in eastern China as an example, the applicability of the method was investigated under different parameter combinations. The simulation results show its effectiveness in these cases. In the earlier period, meeting balance requirements is easier using the straight-line capital depreciation method. In the later period, the fixed rate on declining balance method allows to meet the requirements more easily. In general, it is easier to achieve the goal by choosing a smaller and feasible weight matrix coefficient of the control variables.


Assuntos
Indústrias , Abastecimento de Água , China , Água
17.
J Environ Manage ; 270: 110878, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721317

RESUMO

Located in the hinterland of the Eurasian continent, the inland areas of northwestern China have an arid climate and are confronted with continuing challenges in water resources quantity and quality. Reclaimed water plays an important role in maintaining the sustainable use of urban water resources, especially in arid regions. In this paper, a system dynamics urban reclaimed water model (SDURWM) considering the status of arid regions in northwestern China was constructed. The supply and demand balance index (RWB) and the utilization efficiency index (RWUE) of reclaimed water were proposed as evaluation indicators. The potential of reclaimed water utilization (2016-2025) in three typical cities with similar natural environments and population sizes but with large economic differences were estimated by the SD model. Then the relevant values of reclaimed water quota, supply and resident awareness were adjusted within the range of 10%-20%. The predicted results from intervention demonstrate that the RWB of three cities will be closer or maintain to the ideal value, and that the RWUE will increase by about 0.1, compared with the non-intervention results. This indicates that a minor change of the targeted policies can invigorate the capacity of reclaimed water use in droughty cities. This paper provides some effective solutions for the government's planning of developing the potential of reclaimed water.


Assuntos
Purificação da Água , Água , China , Cidades , Abastecimento de Água
18.
Environ Pollut ; 266(Pt 3): 115143, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32682184

RESUMO

Land use/Land cover (LULC) associated with Cryptosporidium sp. and Giardia sp. quantification and distribution can provide identification of the environmental circulation patterns of these parasites. The aim of this research was to relate the occurrence and circulation of these parasites to the LULC watershed with poor sanitation infrastructure and livestock as important economic activity. The study involved 11 municipalities in the state of São Paulo, located in southeastern Brazil. Sampling was carried out at the catchment sites of each water supply on a monthly basis, starting in December 2014 and lasting until November 2015, totalizing 128 samples. Protozoans were quantified according to the 1623.1 US. EPA Method. For watershed delimitation, the hydrographic network was extracted from the hydrology tool of ArcGIS 10.1. The frequency of occurrence of these pathogens and the high concentrations were evidenced in the municipality with the largest urban area (16.2%) and intense livestock activity (39%) near the catchment site. The municipality that showed the lowest frequency of occurrence presented the smallest urban area (0.87%) and absence of livestock activity near the catchment site. The high concentration of pathogens suggests a correlation between the impact on water supply networks and river basin degradation caused by urban activity and livestock.


Assuntos
Criptosporidiose , Cryptosporidium , Animais , Brasil , Cidades , Giardia , Abastecimento de Água
19.
Environ Pollut ; 266(Pt 1): 115195, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32683234

RESUMO

Breaking of biochar during compaction of amended soil in roadside biofilters or landfill cover can affect infiltration and pollutant removal capacity. It is unknown how the initial biochar size affects the biochar breaking, clogging potential, and contaminant removal capacity of the biochar-amended soil. We compacted a mixture of coarse sand and biochar with sizes smaller than, similar to, or larger than the sand in columns and applied stormwater contaminated with E. coli. Packing columns with biochar pre-coated with a dye and analyzing the dye concentration in the broken biochar particles eluted from the columns, we proved that biochar predominantly breaks under compaction by disintegration or splitting, not by abrasion. Increases in biochar size decrease the likelihood of biochar breaking. We attribute this result to the effective dissipation of compaction energy through a greater number of contact points between a large biochar particle and the adjacent particles. Most of the broken biochar particles are deposited in the pore spaces of the background geomedia, resulting in an exponential decrease in hydraulic conductivity of amended sand with an increase in suspended sediment loading. The clogging rate was higher in the columns with small biochar. The columns with small biochar also exhibited high E. coli removal capacity, partly because of an increase in bacterial straining at reduced pore size after compaction. These results are useful in selecting appropriate biochar size for its application in soils and roadside biofilters for stormwater treatment.


Assuntos
Chuva , Purificação da Água , Carvão Vegetal , Escherichia coli , Solo , Abastecimento de Água
20.
PLoS One ; 15(7): e0235079, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614838

RESUMO

In times of water shortage, it becomes increasingly relevant for policymakers to understand the existing relationships between different types of water use, so as to encourage efficient water management. This article makes use of yearly data on agricultural, industrial, and household water use in the Balkan countries of Bulgaria, Romania, and Serbia. It does so to identify the potential interactions among these three categories of water use. Using a deterministic model based on differential equations, we provide an analysis of the interactions among these different sectors of water use for the period between 2008 and 2017. Results show that interactions among these different categories do not remain constant over periods of time, either across or within the countries analysed. We find that, for most countries, industrial and household water uses are more likely to be characterised by mutualism and competition, instead of a predator-prey relationship. Agricultural water use, on the other hand, takes on the role of predator against the other two.


Assuntos
Conservação dos Recursos Hídricos , Recursos Hídricos , Agricultura , Península Balcânica , Bulgária , Características da Família , Indústrias , Romênia , Sérvia , Recursos Hídricos/provisão & distribução , Abastecimento de Água
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