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1.
J Environ Manage ; 250: 109505, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31518799

RESUMO

Water stress is an increasing burden in regions with arid climates, aquifer vulnerability, and erratic rainfall. Population growth and competing domestic, industrial, and agricultural uses are also stretching the capacity of water supply systems. Beyond groundwater extraction, surface water overuse, and inter-basin transfers, governments are exploring alternative sources amidst looming supply threats. These alternatives include desalination, greywater recycling, and reclaimed or recycled wastewater. The latter, also known as water reuse with varying levels of treatment, has been applied for irrigation, street cleaning, industrial processes, and groundwater recharge. However, reused water for potable purposes has seen limited uptake, due in part to lack of public acceptance. This article examines the dynamics of public acceptance for potable water reuse. The article's theoretical contribution is a formal mathematical model for understanding public acceptance of water reuse. The model conceptualizes how governments, water utilities and the public interact to facilitate or hinder acceptance of water supply sources, including potable reuse. The article concludes by applying the model to cases of water reuse in Windhoek, Namibia, and Singapore.


Assuntos
Água Potável , Purificação da Água , Conservação dos Recursos Naturais , Namíbia , Singapura , Águas Residuárias , Abastecimento de Água
2.
Water Environ Res ; 91(10): 1080-1090, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31410912

RESUMO

Literature published in 2018 pertinent to water reclamation and reuse has been classified into five topics: safe reuse, treatment technologies, management, assessment, and case studies. Researches have been conducted to develop new technologies and improve conventional treatments for achieving sustainable wastewater reclamation, and increasing efforts have been made to facilitate safe water reuse. PRACTITIONER POINTS: The way of publicity greatly influences people's acceptance of water reuse and willingness to purchase produce irrigated with recycled water. Integrated process is the most commonly used treatment technology to reclaim water. There is a lack of local or regional regulatory and policy for sustainable water management.


Assuntos
Purificação da Água , Água , Conservação dos Recursos Naturais , Reciclagem , Eliminação de Resíduos Líquidos , Águas Residuárias , Abastecimento de Água
3.
J Environ Manage ; 247: 867-876, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376785

RESUMO

The world faces imminent drought-related challenges that, from a tap-water supply perspective, require increasingly expensive infrastructure enhancement and energy expansion to maintain sufficient service levels. This paper argues that enhancing domestic water conservation provides a promising alternative or necessary addition to reduce costs and to stimulate pro-environmental behaviour. Although the number of field experiments on how people's behaviour can be changed with respect to their daily water consumption is growing, to date, most studies in this field have focussed either on explanatory socio-economic factors (e.g. water pricing, income, or family composition) or behavioural intentions and personal characteristics related to behavioural change. Accordingly, there is limited empirically validated knowledge about the use and effectiveness of different influencing tactics to change behaviour. This paper provides a review of the empirically oriented literature in this field and aims to provide an up-to-date assessment that identifies eight different Behavioural Influencing Tactics (BITs) that target long-term water conservation behaviour within households. Our analysis is structured around three information processing routes: the reflective route, the semi-reflective route, and the automatic route. We conclude that the current body of literature is promising and provides a useful body of evidence on the range and effectiveness of individual water conservation mechanisms, but that needs further development to deepen our understanding of how to effectively prolong and reinforce newly formed water conservation routines.


Assuntos
Conservação dos Recursos Hídricos , Pesquisa Empírica , Características da Família , Abastecimento de Água
4.
Sci Total Environ ; 693: 133677, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31377348

RESUMO

Soil loss and erosion is a major environmental problem in the Mediterranean. Soil and water bioengineering uses plants and/or parts of plants along with inert material to create solutions to fulfill soil conservation objectives combined with an ecological rehabilitation approach. The ECOMED project developed novel approaches and tools to specialize the soil and water bioengineering sector within the Mediterranean. The first activity was the Sector Needs Analysis were the responses to an online questionnaire of 110 stakeholders from the region were analyzed. The main conclusion was the need to specialize the soil and water bioengineering sector in the Mediterranean. In addition, 21 soil and water bioengineering case studies in the Mediterranean were reviewed. Many works of this type are implemented in the region, but have flaws because of the lack of training material, design routines, protocols, specific to the region. The second activity developed New Design Routines and Protocols. Specifically, three protocols, one template and one plant database were developed for the region. Finally, in the Training Material activity, six educational modules along with a handbook (that contained modules, protocols, template and case studies) were developed. Overall the ECOMED project generated new and novel material and tools that were lacking in the region to enhance the specialization process of the soil and water bioengineering sector. These should increase the adoption of soil and water bioengineering techniques with better trained and new professionals as well as improve the work performance of these interventions.


Assuntos
Bioengenharia/métodos , Agricultura , Conservação dos Recursos Naturais/métodos , Ecologia , Plantas , Solo , Água
5.
Sci Total Environ ; 685: 1139-1151, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390704

RESUMO

Water saving techniques, such as alternate wetting and drying (AWD), are becoming a necessity in modern rice farming because of climate change mitigation and growing water use scarcity. Reducing water can vastly reduce methane (CH4) emissions; however, this net climate benefit may be offset by enhanced carbon dioxide (CO2) emissions from soil. The main aims of this study were: to determine the effects of AWD on yield and ecosystem C dynamics, and to establish the underlying mechanistic basis for observed trends in net ecosystem C gain or loss in an Italian rice paddy. We investigated the effects of conventional water management (i.e. conventionally flooded paddy; CF) and AWD on biomass accumulation (aboveground, belowground, grain), key ecosystem C fluxes (net ecosystem exchange (NEE), net primary productivity (NPP), gross primary productivity (GPP), ecosystem respiration (ER), autotrophic respiration (RA), heterotrophic respiration (RH)), and soil organic matter (SOM) decay for four common commercial European rice cultivars. The most significant finding was that neither treatment nor cultivar affected NEE, GPP, ER or SOM decomposition. RA was the dominant contributor to ER for both CF and AWD treatments. Cultivar and treatment affected the total biomass of the rice plants; specifically, with greater root production in CF compared to AWD. Importantly, there was no effect of treatment on the overall yield for any cultivar. Possibly, the wetting-drying cycles may have been insufficient to allow substantial soil C metabolism or there was a lack of labile substrate in the soil. These results imply that AWD systems may not be at risk of enhancing soil C loss, making it a viable solution for climate change mitigation and water conservation. Although more studies are needed, the initial outlook for AWD in Europe is positive; with no net loss of soil C from SOM decomposition, whilst also maintaining yield.


Assuntos
Agricultura/métodos , Conservação dos Recursos Hídricos/métodos , Oryza/crescimento & desenvolvimento , Biomassa , Ecossistema , Europa (Continente)
6.
Environ Sci Pollut Res Int ; 26(25): 25452-25466, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31264157

RESUMO

Soil erosion constitutes a serious threat for sustainable agriculture in many countries. Magnetic susceptibility of soil is a fast, cheap, and non-destructive technique that could be used to quantify soil erosion or soil redistribution on a long-term scale. This study attempts to analyze the variation of magnetic susceptibility in soil profiles having the same lithology and climatic conditions, but different land uses and slope gradients in a subcatchment in northern Morocco. Soil cores were collected on forested, cultivated, and pasture lands. Each core was associated to a field unit (also called a homogeneous unit) characterized by a set of four cited erosion factors. The samples were measured for mass-specific low-frequency magnetic susceptibility (χlf) and frequency-dependent magnetic susceptibility (χfd). The linear correlation of χlf and χfd indicates the homogeneity of magnetic population in soil. It supports the use of empirical models based on comparisons of χlf to predict the value of magnetic parameter after tillage homogenization and removal of soil material from the surface, and to estimate soil erosion or redeposition. The study built a methodology improving these empirical models and enabling a quantitative approach of the phenomenon. Two models, namely "tillage homogenization" (as improved in this study) and the proposed "simple correlation" result in globally similar estimates of erosion, while another model, the "simple proportional" model, underestimates it. The results give an estimate of long-term erosion (deposition) in sampled units and allow drawing of an areal soil redistribution map in the watershed.


Assuntos
Solo/química , Água , Agricultura/métodos , Conservação dos Recursos Naturais , Marrocos
7.
J Environ Manage ; 246: 881-896, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261015

RESUMO

Strategies for sustainable water resources management require integration of hydrological, ecological and socio-economic concerns. The "Water for all" project has sought to develop a multi-disciplinary science case for innovative management of water levels and flows in a lowland catchment in Scotland. Water demands of arable agriculture, protection from flood risk and conservation needs of lowland mesotrophic wetlands needed to be considered. Water management strategy focused on the outlet zone of Balgavies lake in Eastern Scotland, where the Lunan Water discharges into a partially confined common channel (lade). Water releases to a mill, to the downstream river, and to floodplain wetlands (Chapel Mires) are partially controlled by an existing weir. Based on observations of management of this weir, we postulated that upgrading hydraulic management in this zone could reduce upstream flood risk, help protect mesotrophic wetlands and facilitate downstream water supply at low flows. We considered potential for: (a) installing a remotely operated tilting weir, for improved management of release and routing of flows from the common lade; (b) dredging of the common lade in combination or instead of the tilting weir. Rapid ecological assessment and mixing analysis of the Lunan Water with waters in Chapel Mires showed a gradient of trophic status across the wetlands linked to impact of river-borne nutrients. Stage-discharge relationships, derived from steady-state approximations of the in-channel hydraulics, showed that the proposed tilting weir had potential to divert seasonal nutrient rich water from the upstream Lake away from Chapel Mires. Significant impact of the proposed weir on upstream flood risk was not demonstrated, but carrying out dredging of the channel reduced the current observed probability of upstream flooding. The proposed weir could help to maintain these dredging benefits. Survey and interviews with catchment stakeholders and residents showed constructive interest in the scheme, with half of the respondents willing to pay to support its implementation. The survey also revealed concerns about the proposed project, especially its long-term governance. The lessons learned have wider relevance to development of an integrated approach to water ecosystem services provision, especially where benefits are uncertain and thinly spread across a range of users.


Assuntos
Inundações , Áreas Alagadas , Conservação dos Recursos Naturais , Ecossistema , Comportamento de Redução do Risco , Escócia
8.
Water Res ; 162: 200-213, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31276984

RESUMO

Greywater recycling and rainwater harvesting have the potential to increase the resilience of water management and reduce the need for investment in conventional water supply schemes. However, their water-savings would partly depend on the location and built-form of urban development and hence its household sizes and rainwater per dwelling. We have therefore tested how spatial planning options would affect the future viability of alternative water supply in the Greater South East of England. Our integrated modelling framework, for the first time, forecasts the future densities and variability of built-form to provide inputs to the modelling of alternative water supply. We show that using projections of the existing housing stock would have been unsound, and that using standard dwelling types and household sizes would have substantially overestimated the water-savings, by not fully representing how the variability in dwelling dimensions and household-sizes would affect the cost effectiveness of these systems. We compare the spatial planning trend over a 30 year period with either compaction at higher densities within existing urban boundaries, or market-led more dispersed development. We show how the viability of alternative water supply would differ between these three spatial planning options. The water-savings of rainwater harvesting would vary greatly at a regional scale depending on residential densities and rainfall. Greywater recycling would be less affected by spatial planning but would have a finer balance between system costs and water-savings and its feasibility would vary locally depending on household sizes and water efficiency. The sensitivity of the water savings to differences in rainfall and water prices would vary with residential density. The findings suggest that forecasts of residential densities, rainfall and the water price could be used in conjunction with more detailed local studies to indicate how spatial planning would affect the future water saving potential of alternative water supply.


Assuntos
Conservação dos Recursos Naturais , Abastecimento de Água , Planejamento de Cidades , Inglaterra , Habitação , Chuva , Reciclagem
9.
Water Res ; 163: 114848, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31352242

RESUMO

At times, certain areas of China suffering from water shortages. While China's government is spurring innovation and infrastructure to help head off such problems, it may be that some water conservation could help as well. It is well-known that water is embodied in traded goods-so called "virtual water trade" (VWT). In China, it seems that many water-poor areas are perversely engaged in VWT. Further, China is engaging in the global trend of fragmentation in production, even as an interregional phenomenon. Perhaps something could be learned about conserving or reducing VWT, if we knew where and how it is practiced. Given some proximate causes, perhaps viable policies could be formulated. To this end, we employ China's multiregional input-output tables straddling two periods to trace the trade of a given region's three types of goods: local final goods, local intermediate goods, and goods that shipped to other regions and countries. We find that goods traded interregionally in China in 2012 embodied 30.4% of all water used nationwide. Nationwide, water use increased substantially over 2007-2012 due to greater shipment volumes of water-intensive products. In fact, as suspected, the rise in value chain-related trade became a major contributing factor. Coastal areas tended to be net receivers of VWT from interior provinces, although reasons differed, e.g. Shanghai received more to fulfill final demand (67.8% of net inflow) and Zhejiang for value-chain related trade (40.2% of net inflow). In sum, the variety of our findings reveals an urgent need to consider trade types and water scarcity when developing water resource allocation and conservation policies.


Assuntos
Conservação dos Recursos Hídricos , Recursos Hídricos , China , Água , Abastecimento de Água
10.
Artigo em Inglês | MEDLINE | ID: mdl-31121932

RESUMO

The 2303 Wetlands of International Importance distribute unevenly in different continents. Europe owns the largest number of sites, while Africa has the largest area of sites. More than half of the sites are affected by three or four impact factors (55%). The most significant impact factors are pollution (54%), biological resources use (53%), natural system modification (53%), and agriculture and aquaculture (42%). The main affected objects are land area and environment of the wetlands, occurred in 75% and 69% of the sites, respectively. The types most affected by land area occupation are river wetlands and lake wetlands, the types with the greatest impact on environment are marine/coastal wetlands and river wetlands, the type with the greatest impact on biodiversity is river wetlands, the types most affected by water resources regulation are marsh wetlands and river wetlands, and the types most affected by climate change are lake wetlands and marine/coastal wetlands. About one-third of the wetland sites have been artificially reconstructed. However, it is found that the proportions of natural wetland sites not affected or affected by only one factor are generally higher than that of wetland sites both containing natural wetlands and human-made wetlands, while the proportions of wetland sites both containing natural wetlands and human-made wetlands affected by three or four factors are generally higher than that of natural wetland sites. Wetland sites in the UK and Ireland are least affected among all countries. Wetland management plans in different regions still have large space for improvement, especially in Africa and Asia. The protection and restoration of global wetlands can be carried out in five aspects, including management and policy, monitoring, restoration, knowledge, and funding.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Monitoramento Ambiental , Áreas Alagadas
11.
Environ Sci Pollut Res Int ; 26(18): 18624-18635, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31055751

RESUMO

Contamination of surface water and groundwater streams with carcinogenic chemicals such as arsenic (As) has been a major environmental issue worldwide, and requires significant attention to develop new and low-cost sorbents to treat As-polluted water. In the current study, arsenite (As(III)) and arsenate (As(V)) removal efficiency of peanut shell biochar (PSB) was compared with peanut shell (PS) in aqueous solutions. Sorption experiments showed that PSB possessed relatively higher As removal efficiency than PS, with 95% As(III) (at pH 7.2) and 99% As(V) (at pH 6.2) with 0.6 g L-1 sorbent dose, 5 mg L-1 initial As concentration, and 2 h equilibrium time. Experimental data followed a pseudo-second-order model for sorption kinetics showing the dominance of chemical interactions (surface complexation) between As and surface functional groups. The Langmuir model for sorption isotherm indicated that As was sorbed via a monolayer sorption process. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that the hydroxyl (-OH) and aromatic surface functional (C=O, C=C-C, and -C-H) groups contributed significantly in the sorption of both As species from aqueous solutions through surface complexation and/or electrostatic reactions. We demonstrate that the pyrolysis of abandoned PS yields a novel, low-cost, and efficient biochar which provides dual benefits of As-rich water treatment and a value-added sustainable strategy for solid waste disposal.


Assuntos
Arachis/química , Arsênico/isolamento & purificação , Carvão Vegetal/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Arsênico/química , Conservação dos Recursos Naturais , Concentração de Íons de Hidrogênio , Cinética , Propriedades de Superfície , Poluentes Químicos da Água/química
12.
Sci Total Environ ; 674: 615-622, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31029025

RESUMO

Fires are a complex phenomenon that may generate a chain of responses and processes that affect each part of the ecosystem. Thus, it is important to understand the magnitude of the impacts of fire on soil properties and the response of plants to this disturbance. For the moment, few studies have examined the effects of prescribed fire on large plots in afforested pine plantations in Mediterranean ecosystems. To fill this gap, the effects of a prescribed fire on runoff, soil erosion, and water quality for approximately one year after burning have been evaluated in pine plantations in south-eastern Spain. We constructed six erosion plots in the control area and six erosion plots in the burned area that were 4 m long and 2 m wide, immediately after the prescribed fire. Runoff, soil erosion and runoff water quality were studied after each rainy event in all plots. Our results reveal that prescribed fire did not significantly affect runoff and soil erosion when low intensity precipitations occur at pine plantations. In relation to water quality, water turbidity, salinity, pH, organic matter content and ionic substances concentrations increased immediately after prescribed burn, nevertheless these changes disappeared over time. We can conclude that prescribed fire can be a useful tool for fuel reduction in Mediterranean pine plantations without wide and long-term impacts to soil losses, or water quality.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Fogo , Ecossistema , Monitoramento Ambiental , Fazendas , Fenômenos Geológicos , Região do Mediterrâneo , Pinus , Chuva , Solo , Espanha , Qualidade da Água
13.
Sci Total Environ ; 673: 207-217, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30986680

RESUMO

India has the highest national freshwater demand globally and 91% of India's freshwater is used in the agriculture sector. Cereals account for over 50% of the dietary water footprint in India and represent a potential opportunity for reducing water use in Indian agriculture. This study combines governmental production and irrigation statistics with crop distribution maps to examine trends in annual water use for cereal production in India between 2005 and 2014. A new online water assessment tool, Cool Farm Tool Water (CFTW), was used to calculate water use and derive seasonal state-level blue and green water footprints for rice, wheat, sorghum, millet and maize. The analysis indicates that India achieved 26.4% increased total cereal production between 2005 and 2014 without additional water or land use. Cereal water footprints have declined due to higher yields for most crops and slightly lower rates of evapotranspiration. There has also been a shift in the area under production away from the Kharif (monsoon) towards the Rabi (dry) season in which total water footprints for all cereals except rice are substantially lower (-33.4% to -45.0% compared to Kharif), but show a significantly higher dependency on ground and surface water. The value of this study is two-fold. First, it provides a full assessment of production trends for the five major cereals in India for each year from 2005 to 2014 and links it to water use. Secondly, it uses updated seasonal water footprints, which demonstrate the potential for changes in cereal production practices to contribute to improved efficiency of water use in India. Future pressures on scarce water resources may encourage transition to cereals with lower irrigation dependency, in particular maize, but also sorghum and millet. In addition, increased emphasis on improving millet and sorghum yields would be of benefit to secure cereal production and reduce its overall water footprint.


Assuntos
Agricultura/métodos , Grão Comestível/crescimento & desenvolvimento , Recursos Hídricos/provisão & distribução , Abastecimento de Água/estatística & dados numéricos , Agricultura/estatística & dados numéricos , Conservação dos Recursos Hídricos/estatística & dados numéricos , Produtos Agrícolas , Fertilizantes , Índia , Milhetes , Oryza , Sorghum , Triticum , Zea mays
14.
J Environ Qual ; 48(2): 340-351, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30951116

RESUMO

The degradation of freshwater resources and loss of freshwater biodiversity by anthropogenic activities, including agriculture, are of major global concern. Together with diffuse pollutants, point sources, such as where cattle have direct access to riparian margins and watercourses, can potentially present significant environmental challenges. These can include impacts on stream morphology, increased sedimentation, nutrient additions, microbial contamination, and impacts on aquatic biota. Mitigation measures aimed at reducing these frequently include reducing the amount of time cattle spend in riparian margins and watercourses. This is often accomplished through the provision of an alternative water supply and grazing management, or even cattle exclusion measures. Although a number of studies refer to potential negative impacts, there has been little attempt to review previous research on this topic. The key aim of this paper is to collate and review these disparate studies, as well as those relating to the effectiveness of mitigation measures. Although it is difficult to draw generalizations from studies due to the inherent variability between and within catchments, evidence pertaining to impacts in relation to sedimentation, pathogens, and riparian margin vegetation were strong. Conclusions in relation to impacts on stream morphology and nutrient parameters were less clear, whereas studies on responses of macroinvertebrate communities were particularly variable, with differences due to cattle access difficult to separate from catchment scale effects. A greater understanding of the impact of cattle access on watercourses under varying conditions will help inform policymakers on the cost effectiveness of existing management criteria and will help in revising existing measures.


Assuntos
Criação de Animais Domésticos , Conservação dos Recursos Naturais , Monitoramento Ambiental , Rios , Agricultura , Animais , Bovinos , Ecossistema , Abastecimento de Água
15.
Acta Trop ; 193: 217-226, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30857860

RESUMO

The water-related exposome is a significant determinant of human health. The disease burden through water results from water-associated communicable and non-communicable diseases and is influenced by water pollution with chemicals, solid waste (mainly plastics), pathogens, insects and other disease vectors. This paper analyses a range of water practitioner-driven health issues, including infectious diseases and chemical intoxication, using the conceptual framework of Drivers, Pressures, State, Impacts, and Responses (DPSIR), complemented with a selective literature review. Pressures in the environment result in changes in the State of the water body: chemical pollution, microbiological contamination and the presence of vectors. These and other health hazards affect the State of human health. The resulting Impacts in an exposed population or affected ecosystem, in turn incite Responses. Pathways from Drivers to Impacts are quite divergent for chemical pollution, microbiological contamination and the spread of antimicrobial resistance, in vectors of disease and for the combined effects of plastics. Potential Responses from the water sector, however, show remarkable similarities. Integrated water management interventions have the potential to address Drivers, Pressures, Impacts, and State of several health issues at the same time. Systematic and integrated planning and management of water resources, with an eye for human health, could contribute to reducing or preventing negative health impacts and enhancing the health benefits.


Assuntos
Doenças Transmissíveis/transmissão , Conservação dos Recursos Hídricos , Microbiologia da Água , Poluição Química da Água/prevenção & controle , Animais , Controle de Doenças Transmissíveis , Vetores de Doenças , Ecossistema , Política de Saúde , Humanos , Plásticos , Poluição Química da Água/efeitos adversos
16.
BMC Infect Dis ; 19(1): 242, 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30871485

RESUMO

BACKGROUND: Diarrheal disease kills over half a million people each year in sub-Saharan Africa; the majority are children under 5 years. About 58% of diarrhea cases are associated with poor water, sanitation, and hygiene-a critical issue for people living in informal settlements. In Kenya, 60% of Nairobi's population lives in informal settlements; yet, there is a paucity of research exploring the relationship between water, sanitation and hygiene (WASH) conditions in these settlements and associated health outcomes. METHODS: The study examines characteristics of women's WASH behaviors and environments as potential factors associated with household diarrhea in Mathare Valley Informal Settlement in Nairobi using cross-sectional survey data collected from 550 women. RESULTS: Approximately 17% of participants reported that at least one member of the household suffered from diarrhea in the previous 2 weeks-48% of the cases were children under five. Results from a logistic regression exploring factors associated with reports of household diarrhea suggest that women's sanitation management strategies are associated with recent household diarrhea. Women who use toilets for defecation during the day, but rely on bags, buckets, or open defecation (OD) for urination during the day and for urination and defecation at night have over five time the odds of recent household diarrhea than women who use a toilet for all their sanitation needs. The odds of diarrhea were also higher for participants who walk up to 2 min to reach their toilets/sites for defecation and those who rely on water from taps inside buildings and plots. Odds were 62% lower for participants with clean toilets. CONCLUSIONS: Findings suggest that health targets to reduce the prevalence of diarrheal diseases in informal settlements may not be met unless particular attention is paid to the needs of women living in these environments.


Assuntos
Diarreia/etiologia , Saneamento , Adulto , Aparelho Sanitário , Pré-Escolar , Estudos Transversais , Água Potável , Características da Família , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Higiene , Quênia , Masculino , Áreas de Pobreza , Prevalência
17.
Sci Total Environ ; 667: 25-32, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30825818

RESUMO

Green roofs are novel urban ecosystems with shallow substrate depths and low water availability. Hence, it is critical to select green roof plants that can survive water-deficits, particularly in climates with hot and dry summers. Shrubs are perennial plants which can be drought resistant and may be suitable for green roofs. However, studies about survival and health of shrubs are limited. The aim of this study was to determine whether plant climate of origin aridity, drought response and water use strategies could be used to select shrubs which can survive on green roofs that experience water-deficit. We selected 15 shrub species from a range of climates (dry, mesic and wet) and planted them together in 20 replicate green roof modules with 130 mm deep substrate. We monitored substrate water contents, plant minimum water potentials (ψmin), health (visual score), percentage survival and related survival with their turgor loss point (ψtlp) and water use strategies (evapotranspiration rates in a related glasshouse experiment). We also determined whether plants could recover after dry periods by rewatering after the summer. Mean gravimetric soil water content decreased to approximately 5% after summer drought, which resulted in mortality. Overall, survival ranged between 10% and 100% for the 15 species. However, survival was not related to their ψtlp or water use strategies. While shrubs from more arid climates had lower ψmin in response to dry substrates, this did not result in greater survival and health. Following rewatering, only four shrub species resprouted. Hence, as plant drought response, water use strategy and climate of origin were not strongly related to survival, we suggest survival on green roofs is likely to be determined by a combination of physiological traits. Emergency irrigation for shrubs growing on green roofs in hot and dry climates is recommended during summer to keep them alive.


Assuntos
Clima Desértico , Secas , Magnoliopsida/fisiologia , Água/metabolismo , Conservação dos Recursos Naturais , Longevidade , Magnoliopsida/crescimento & desenvolvimento , Vitória
18.
Water Sci Technol ; 79(1): 3-14, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30816857

RESUMO

The wastewater industry is currently facing dramatic changes, shifting away from energy-intensive wastewater treatment towards low-energy, sustainable technologies capable of achieving energy positive operation and resource recovery. The latter will shift the focus of the wastewater industry to how one could manage and extract resources from the wastewater, as opposed to the conventional paradigm of treatment. Debatable questions arise: can the more complex models be calibrated, or will additional unknowns be introduced? After almost 30 years using well-known International Water Association (IWA) models, should the community move to other components, processes, or model structures like 'black box' models, computational fluid dynamics techniques, etc.? Can new data sources - e.g. on-line sensor data, chemical and molecular analyses, new analytical techniques, off-gas analysis - keep up with the increasing process complexity? Are different methods for data management, data reconciliation, and fault detection mature enough for coping with such a large amount of information? Are the available calibration techniques able to cope with such complex models? This paper describes the thoughts and opinions collected during the closing session of the 6th IWA/WEF Water Resource Recovery Modelling Seminar 2018. It presents a concerted and collective effort by individuals from many different sectors of the wastewater industry to offer past and present insights, as well as an outlook into the future of wastewater modelling.


Assuntos
Conservação dos Recursos Hídricos/métodos , Eliminação de Resíduos Líquidos/métodos , Recursos Hídricos/provisão & distribução , Abastecimento de Água/estatística & dados numéricos , Conservação dos Recursos Hídricos/estatística & dados numéricos , Hidrodinâmica , Modelos Estatísticos , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias
19.
Environ Monit Assess ; 191(2): 117, 2019 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-30706206

RESUMO

The environmental protection area of Lageado was created in 2001 in Campo Grande, Mato Grosso do Sul's State capital, and it constitutes a conservation unit that belongs to the Sustainable Use Group. The environmental protection area of Lageado is located in an urban area and provides approximately 12% of the water supplied to the municipality. Knowing the relationship between soil occupancy and population density, which may cause harmful effects to the quality of surface water and water resources, is fundamental. The present study aims to analyse the physical-chemical parameters of water samples collected at three different times and in six distinct points in Lageado. To verify whether the transformation of this watershed into a conservation unit resulted in the maintenance of water quality, the statistical analyses considered the significance and correlation among the following parameters: water quality index (WQI); dissolved aluminium, iron and copper; Escherichia coli; nitrate; ammoniacal nitrogen; Kjeldahl nitrogen; chemical oxygen demand; and chlorophyll α. The results show that the formal creation of the environmental protection area of Lageado did not provide the effective improvement or maintenance of its environmental conditions. Statistically, there were decreases in the WQI over the studied period, which demonstrates that the creation of a conservation unit is, in itself, not sufficient and it lacks the implementation of effective programmes and actions related to the soil use, occupancy and water quality.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Rios/química , Qualidade da Água/normas , Brasil , Cidades , Poluição da Água/análise , Recursos Hídricos
20.
Mar Pollut Bull ; 140: 274-280, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30803643

RESUMO

Plastics in the ocean are of great concern nowadays, and are often referred to as the apocalyptic twin of climate change in terms of public fear and the problems they pose to the aquatic and terrestrial environment. The number of studies focusing on the ecological effects and toxicity of plastics has substantially increased in the last few years. Considering the current trends in the anthropogenic activities, the amount of plastics entering the world oceans is increasing exponentially, but the oceans have a low assimilative capacity for plastics and the near-surface layer of it is a finite space. If loading of the oceans with plastics continues at the current rate, the thin sea surface microlayer can have a substantial amount of plastics comparable to the distribution of phytoplankton, at least in the major oceanic gyres and coastal waters in the future. Also, processes like biofouling can cluster microplastics in dense fields in the near-surface layer. Plastics can contribute to the warming or cooling of the water column by scattering and attenuating incoming solar radiation, leading to a potential change in the optical and other physico-chemical properties of the water column. We propose a new notion that changes in solar radiation in the water column due to the plastics have the potential to affect the physical processes in the ocean surface and near-surface layers, and can induce climate feedback cycles. The future can be very different, if plastics evolve as one of the key players affecting the ocean physical processes and hence this is the time to tackle this puzzle with appropriate strategies or let the genie out of the bottle.


Assuntos
Mudança Climática , Conservação dos Recursos Hídricos/tendências , Plásticos/análise , Água do Mar , Poluentes Químicos da Água/análise , Incrustação Biológica/prevenção & controle , Ecossistema , Oceanos e Mares , Fitoplâncton/crescimento & desenvolvimento , Plásticos/efeitos da radiação , Água do Mar/química , Água do Mar/microbiologia , Poluentes Químicos da Água/efeitos da radiação
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