Assuntos
População Rural , Engenharia Sanitária , Eliminação de Resíduos Líquidos , População Rural/estatística & dados numéricos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Purificação da Água , Engenharia Sanitária/métodos , Engenharia Sanitária/tendências , Aparelho Sanitário/provisão & distribuiçãoRESUMO
The microbial community of the landfill undergoing aerobic stabilization process by aeration engineering was investigated. The municipal solid wastes (MSWs) were sampled from two aeration well sites with different landfill temperatures (65.5°C and 41.7°C) under higher and lower stabilization level. The physical component, chemical property, and microbial population of MSWs were analyzed and compared. The result showed that the phylum Firmicutes was dominant in the aerobic landfill; and the genus Weissella and Syntrophaceticus were more abundant in high, and low temperature site, respectively. The bacterial distribution showed difference on two temperature sites and four landfill depths, mainly affected by the ammonia-nitrogen and moisture content of MSWs. The ecological profiles of the microorganisms responded the aeration engineering were predicted. The anaerobic hydrolytic and acetogenic microorganisms were decreased in abundance, while the facultative Lactobacillus increased when the landfill under a higher stabilization level. The function abundances of methane oxidation, sulfide oxidation, and aerobic chemoheterotrophy were enriched by aeration engineering, which was the microbial mechanism for accelerating the stabilization process of landfill.
Assuntos
Bactérias , Oxigênio , Instalações de Eliminação de Resíduos , Resíduos Sólidos , Pequim , Bactérias/classificação , Bactérias/metabolismo , Engenharia Sanitária/métodos , Biodegradação AmbientalRESUMO
The deadliest coronavirus disease 2019 (COVID-19) is taking thousands of lives worldwide and presents an extraordinary challenge to mental resilience. This study assesses mental health status during the COVID-19 pandemic and its associated factors among informal waste workers in Bangladesh. A cross-sectional survey was conducted in June 2020 among 176 informal waste workers selected from nine municipalities and one city corporation in Bangladesh. General Health Questionnaire (GHQ-12) was used to assess respondents' mental health. The study found that 80.6% of the individuals were suffering from psychological distress; 67.6% reported anxiety and depression, 92.6% reported social dysfunction, and 19.9% reported loss of confidence. The likelihood of psychological distress (Risk ratio [RR]: 1.23, 95% confidence interval [CI]: 1.02-1.48) was significantly higher for female than male. Multiple COVID-19 symptoms of the family members (RR: 1.20, 95% CI: 1.03-1.41), unawareness about COVID-19 infected neighbor (RR: 1.21, 95% CI: 1.04-1.41), income reduction (RR: 1.60, 95% CI: 1.06-2.41) and daily household meal reduction (RR: 1.34; 95% CI: 1.03-1.73) were also found to be associated with psychological distress. These identified factors should be considered in policy-making and support programs for the informal waste workers to manage the pandemic situation as well as combating COVID-19 related psychological challenges.
Assuntos
COVID-19/psicologia , Saúde Mental/tendências , Trabalhadores Pobres/psicologia , Adulto , Ansiedade , Transtornos de Ansiedade , Bangladesh/epidemiologia , COVID-19/epidemiologia , Estudos Transversais , Depressão , Transtorno Depressivo , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Angústia Psicológica , SARS-CoV-2/patogenicidade , Engenharia Sanitária/métodos , Engenharia Sanitária/tendências , Inquéritos e QuestionáriosRESUMO
The hospital environment has been reported as a source of transmission events and outbreaks of carbapenemase-producing Enterobacterales. Interconnected plumbing systems and the microbial diversity in these reservoirs pose a challenge for outbreak investigation and control. A total of 133 clinical and environmental OXA-48-producing Enterobacter cloacae isolates collected between 2015 and 2021 were characterized by whole-genome sequencing (WGS) to investigate a prolonged intermittent outbreak involving 41 patients in the hematological unit. A mock-shower experiment was performed to investigate the possible acquisition route. WGS indicated the hospital water environmental reservoir as the most likely source of the outbreak. The lack of diversity of the blaOXA-48-like harbouring plasmids was a challenge for data interpretation. The detection of blaOXA-48-like-harboring E. cloacae strains in the shower area after the mock-shower experiment provided strong evidence that showering is the most likely route of acquisition. Initially, in 20 out of 38 patient rooms, wastewater traps and drains were contaminated with OXA-48-positive E. cloacae. Continuous decontamination using 25% acetic acid three times weekly was effective in reducing the trap/drain positivity in monthly environmental screening but not in reducing new acquisitions. However, the installation of removable custom-made shower tubs did prevent new acquisitions over a subsequent 12-month observation period. In the present study, continuous decontamination was effective in reducing the bacterial burden in the nosocomial reservoirs but was not sufficient to prevent environment-to-patient transmission in the long term. Construction interventions may be necessary for successful infection prevention and control. IMPORTANCE The hospital water environment can be a reservoir for a multiward outbreak, leading to acquisitions or transmissions of multidrug-resistant organisms in a hospital setting. The majority of Gram-negative bacteria are able to build biofilms and persist in the hospital plumbing system over a long period of time. The elimination of the reservoir is essential to prevent further transmission and spread, but proposed decontamination regimens, e.g., using acetic acid, can only suppress but not fully eliminate the environmental reservoir. In this study, we demonstrated that colonization with multidrug-resistant organisms can be acquired by showering in showers with contaminated water traps and drains. A construction intervention by installing removable and autoclavable shower inserts to avoid sink contact during showering was effective in containing this outbreak and may be a viable alternative infection prevention and control measure in outbreak situations involving contaminated shower drains and water traps.
Assuntos
Proteínas de Bactérias/genética , Enterobacter cloacae/genética , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/prevenção & controle , Controle de Infecções/métodos , Engenharia Sanitária/métodos , beta-Lactamases/genética , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/metabolismo , Genoma Bacteriano/genética , Humanos , Unidades de Terapia Intensiva , Microbiologia da Água , Sequenciamento Completo do Genoma , beta-Lactamases/metabolismoRESUMO
This Viewpoint calls for a greater understanding of the role that water plays in the transmission of anti-microbial resistance and covid-19 in protracted urban armed conflict, in order to develop a 'pathogen-safe' practice. It argues that dealing with the twin threats is difficult enough in the best of circumstances, and is so little understood in war zones that surgeons and water engineers now question if their practice does more harm than good. Experience suggests that the known transmission routes are complicated by a great number of factors, including the entry of heavy metals through bullets in patients' wounds, hospital over-crowding, mutation in treated water or wastewater, and other threats which endure long after the bombing has stopped. The skeleton research agenda proposes greater sewage surveillance, testing of phages and monitoring of treatment designed to dispel or substantiate these assertions.
Assuntos
COVID-19 , Transmissão de Doença Infecciosa/prevenção & controle , Saúde Pública , Engenharia Sanitária , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/transmissão , Reservatórios de Doenças , Resistência Microbiana a Medicamentos , Humanos , Fenômenos Microbiológicos , SARS-CoV-2 , Engenharia Sanitária/métodos , Engenharia Sanitária/normasRESUMO
Factors associating environmental degradation with human health have shown that air pollution is a source of morbi-mortality throughout the world. Unfortunately, hospitals are themselves "silent polluters". As healthcare professionals, we are the guarantors not only of quality of patient care, but also of proper hospital conduct. The aim of this attempt at clarification is to outline what can be done in the operating theater to reduce the environmental impact of the treatments we administer. Our recommendations will go above and beyond regulatory frameworks and draw upon daily practice concerning waste management, energy consumption, utilization of anesthetic agents and multiple forms of waste. A number of French and international pilot experimentations have been carried out and could strongly contribute to the modification of clinical practices with a societal impact, at a time when ecology has become one of the main preoccupations of our fellow citizens.
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Conservação dos Recursos Naturais/métodos , Aquecimento Global/prevenção & controle , Salas Cirúrgicas/organização & administração , Engenharia Sanitária/métodos , Responsabilidade Social , Procedimentos Cirúrgicos Operatórios/métodos , Poluição do Ar/efeitos adversos , Poluição do Ar/prevenção & controle , Anestésicos/efeitos adversos , França , Gases de Efeito Estufa/efeitos adversos , Humanos , Cooperação Internacional , Procedimentos Cirúrgicos Operatórios/efeitos adversosRESUMO
Plastic pipes have been and are being installed downstream of metal drinking water plumbing components. Prior research has suggested that such pipe configurations may induce plastic pipe degradation and even system failure. To explore the impact of upstream metal plumbing components on downstream plastic pipes, field- and bench-scale experiments were conducted. Six month old galvanized iron pipes (GIPs) and downstream crosslinked polyethylene (PEX) pipes were exhumed from a residential home. Calcium, iron, manganese, phosphorous, and zinc were the most abundant elements on both GIPs and PEX pipes. Black and yellow deposits were found on some of the exhumed PEX pipe inner walls, which were mainly copper, iron, and manganese oxides (CuO, Cu(OH)2, Fe2O3, FeOOH and MnO2). Follow-up bench-scale experiments revealed that metal levels in the drinking water did not always predict metal loadings on plastic pipe surfaces. The pH 4 water resulted in a greater amount of metals released into the bulk water, but the pH 7.5 water resulted in a greater amount of metals deposited on the PEX pipe surfaces. Hot water (55⯰C) induced a greater amount of organics released and higher metal loadings on PEX pipe surfaces at pH 7.5. ATR-FTIR analysis showed that at 55⯰C, PEX pipes connected to copper and brass components had the greatest oxidation functional group peak intensity (COOC, CO, and COC). This study highlights potential downstream plastic pipe degradation and metal deposition, which may cause plumbing problems and failures for building owners, inhabitants, and water utilities.
Assuntos
Água Potável/química , Metais/química , Engenharia Sanitária/métodos , Corrosão , Abastecimento de Água/métodosRESUMO
Public health has always been, and remains, an interdisciplinary field, and engineering was closely aligned with public health for many years. Indeed, the branch of engineering that has been known at various times as sanitary engineering, public health engineering, or environmental engineering was integral to the emergence of public health as a distinct discipline. However, in the United States (U.S.) during the 20th century, the academic preparation and practice of this branch of engineering became largely separated from public health. Various factors contributed to this separation, including an evolution in leadership roles within public health; increasing specialization within public health; and the emerging environmental movement, which led to the creation of the U.S. Environmental Protection Agency (EPA), with its emphasis on the natural environment. In this paper, we consider these factors in turn. We also present a case study example of public health engineering in current practice in the U.S. that has had large-scale positive health impacts through improving water and sanitation services in Native American and Alaska Native communities. We also consider briefly how to educate engineers to work in public health in the modern world, and the benefits and challenges associated with that process. We close by discussing the global implications of public health engineering and the need to re-integrate engineering into public health practice and strengthen the connection between the two fields.
Assuntos
Engenharia/história , Engenharia/estatística & dados numéricos , Saúde Pública/história , Saúde Pública/estatística & dados numéricos , Saneamento/história , Abastecimento de Água/história , História do Século XX , Humanos , Indígenas Norte-Americanos , Engenharia Sanitária/história , Engenharia Sanitária/métodos , Estados UnidosRESUMO
Drop structures and especially drop manholes are extensively employed in supercritical routes of sewer and drainage systems. Drop manholes remarkably affect hydraulic features of their downstream system, while their operation is dominated by the flow regime inside them. Poor hydraulic performance of these structures under Regime R2 was improved with the jet-breaker, yet its proper dimensions were needed to be precisely determined. In this paper, effects of the jet-breaker length, width, sagitta, and angle on drop manhole energy dissipation and air demand (as responses), under the inlet pipe 80% filling ration, were experimentally studied. The modern statistical design of experiment (DoE) methodology and dimensional analysis were utilized to design the experiments in accordance with the 24-1 IV fractional factorial design. Ten specific jet-breakers were examined and more than 135 tests were performed. The statistical analysis of the results revealed that both responses were significantly improved when the jet-breaker length and width were 2 and 1.4 times the inlet pipe diameter, respectively; its sagitta was equal to 0, and its angle was at 70°. The use of DoE resulted in 21% reduction in experimental runs, straightforward data analysis, and unbiased concluding.
Assuntos
Movimentos do Ar , Modelos Teóricos , Engenharia Sanitária/métodosRESUMO
In the paper, a comparison of prediction results concerning the annual number of discharges of stormwater from the drainage system due to stormwater overflows is depicted. The prediction has been computed by means of storm water management model (SWMM) and probabilistic models. Regarding the probabilistic modelling some simple statistical models such as logit, probit, Gompertz and linear discriminant analysis model have been applied, and as for the hydrodynamic modelling a generator of synthetic rainfall based on the Monte Carlo method has been used. The analyses conducted has shown that logit, probit and Gompertz models give outputs that are comparable with the results of hydrodynamic modelling and are concordant with observations. Whereas the annual number of stormwater discharge predicted by the linear discriminant analysis model is significantly lower than the number obtained by hydrodynamic modelling. The calculations made have confirmed the possibility of using statistical models as an alternative for developing labour-consuming and complex hydrodynamic models. The statistical models can be used successfully to predict the stormwater overflows operation provided that the measurements of rainfall in the catchment and of filling the overflow are available.
Assuntos
Monitoramento Ambiental/métodos , Modelos Teóricos , Chuva , Engenharia Sanitária/métodos , Movimentos da Água , Hidrodinâmica , Modelos Lineares , Método de Monte Carlo , ÁguaRESUMO
Landfill gas (LFG)-to-energy plants in Turkey were investigated, and the LFG-to-energy plant of a metropolitan municipal landfill was monitored for 3 years. Installed capacities and actual gas engine working hours were determined. An equation was developed to estimate the power capacity for LFG-to-energy plants for a given amount of landfilled waste. Monitoring the actual gas generation rates enabled determination of LFG generation factors for Turkish municipal waste. A significant relationship (R = 0.524, p < 0.01, two-tailed) was found between the amounts of landfilled waste and the ambient temperature, which can be attributed to food consumption and kitchen waste generation behaviors influenced by the ambient temperature. However, no significant correlation was found between the ambient temperature and the generated LFG. A temperature buffering capacity was inferred to exist within the landfill, which enables the anaerobic reactions to continue functioning even during cold seasons. The average LFG and energy generation rates were 45 m3 LFG/ton waste landfilled and 0.08 MWhr/ton waste landfilled, respectively. The mean specific LFG consumption for electricity generation was 529 ± 28 m3/MWhr. IMPLICATIONS: The paper will be useful for local authorities who need to manage municipal waste by using landfills. The paper will also be useful for investors who want to evaluate the energy production potential of municipal wastes and the factors affecting the energy generation process mostly for economical purposes. Landfills can be regarded as energy sources and their potentials need to be investigated. The paper will also be useful for policymakers dealing with energy issues. The paper contains information on real practical data such as engine working hours, equation to estimate the necessary power for a given amount of landfilled waste, and son on.
Assuntos
Fontes Geradoras de Energia , Centrais Elétricas , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/métodos , Eliminação de Resíduos , Engenharia Sanitária/métodos , Turquia , Resíduos/análiseRESUMO
Background: The increasing prevalence of nosocomial carbapenemase-producing Enterobacteriaceae is a concern. However, the role of the environment in multispecies outbreaks remains poorly understood. There is increasing recognition that hospital wastewater plumbing may play a role. Methods: Covers were installed on all hoppers (a "toilet-like" waste disposal system) in adult intensive care units (ICUs) of a university hospital; additionally in the surgical ICU, sink trap heating and vibration devices were also installed. Patient acquisitions of Klebsiella pneumoniae carbapenemase-producing organisms (KPCOs) for patients who were admitted to an intervention unit were compared for 18-month preintervention and intervention periods. Results: Sixty hopper covers and 23 sink trap devices were installed. Fifty-six new multispecies KPCO acquisitions occurred preintervention compared to 30 during the intervention. Decreases for all KPCO acquisitions (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.31-0.81; P = .003) and KPCO-positive clinical cultures (OR, 0.29; 95% CI, 0.17-0.48; P < .001) per admission in patients exposed to an intervention unit were observed. The incidence rate ratio was 0.51-fold (95% CI, 0.43-0.61) lower for all KPCO acquisitions during the intervention. The effect of the sink trap devices alone could not be determined, although the proportion of sink drain cultures positive for KPCO decreased (12/15 [80%] sites sampled preintervention vs 40/840 [5%] sampled during the intervention; P = .001). Conclusions: An intervention targeting wastewater plumbing fixtures, by installation of hopper covers, demonstrated a decrease in patient KPCO acquisitions. Considering wastewater reservoirs in nosocomial transmission of multispecies carbapenemase-producing Enterobacteriaceae may be critical.
Assuntos
Controle de Infecções/métodos , Unidades de Terapia Intensiva , Infecções por Klebsiella/prevenção & controle , Klebsiella pneumoniae/isolamento & purificação , Águas Residuárias/microbiologia , Proteínas de Bactérias/metabolismo , Aparelho Sanitário/microbiologia , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Portador Sadio/microbiologia , Infecção Hospitalar , Surtos de Doenças/prevenção & controle , Hospitais Universitários , Humanos , Controle de Infecções/instrumentação , Klebsiella pneumoniae/enzimologia , Estudos Prospectivos , Engenharia Sanitária/métodos , beta-Lactamases/metabolismoRESUMO
Rapid urbanization affecting demand patterns, coupled with potential water shortages due to supply side impacts of climatic changes, has led to the emergence of new technologies for water and wastewater reuse. Sewer mining (SM) is a novel decentralized option that could potentially provide non-potable water for urban uses, including for example the irrigation of urban green spaces, providing a mid-scale solution to effective wastewater reuse. SM is based on extracting wastewater from local sewers and treatment at the point of demand and entails in some cases the return of treatment residuals back to the sewer system. Several challenges are currently in the way of such applications in Europe, including public perception, inadequate regulatory frameworks and engineering issues. In this paper we consider some of these engineering challenges, looking at the sewer network as a system where multiple physical, biological and chemical processes take place. We argue that prior to implementing SM, the dynamics of the sewer system should be investigated in order to identify optimum ways of deploying SM without endangering the reliability of the system. Specifically, both wastewater extraction and sludge return could result in altering the biochemical process of the network, thus unintentionally leading to degradation of the sewer infrastructure. We propose a novel Monte-Carlo based method that takes into account both spatial properties and water demand characteristics of a given area of SM deployment while simultaneously accounting for the variability of sewer network dynamics in order to identify potential locations for SM implementation. The outcomes of this study suggest that the method can provide rational results and useful guidelines for upscale SM technologies at a city level.
Assuntos
Engenharia Sanitária/métodos , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Cidades , Europa (Continente) , Método de Monte Carlo , Reprodutibilidade dos Testes , UrbanizaçãoRESUMO
Regular and continuous monitoring of urban runoff in both quality and quantity aspects is of great importance for controlling and managing surface runoff. Due to the considerable costs of establishing new gauges, optimization of the monitoring network is essential. This research proposes an approach for site selection of new discharge stations in urban areas, based on entropy theory in conjunction with multi-objective optimization tools and numerical models. The modeling framework provides an optimal trade-off between the maximum possible information content and the minimum shared information among stations. This approach was applied to the main surface-water collection system in Tehran to determine new optimal monitoring points under the cost considerations. Experimental results on this drainage network show that the obtained cost-effective designs noticeably outperform the consulting engineers' proposal in terms of both information contents and shared information. The research also determined the highly frequent sites at the Pareto front which might be important for decision makers to give a priority for gauge installation on those locations of the network.
Assuntos
Cidades , Teoria da Informação , Engenharia Sanitária/métodos , Abastecimento de Água , Entropia , Irã (Geográfico) , Movimentos da ÁguaRESUMO
Sudden diverging channels are one of the energy dissipaters which can dissipate most of the kinetic energy of the flow through a hydraulic jump. An accurate prediction of hydraulic jump characteristics is an important step in designing hydraulic structures. This paper focuses on the capability of the support vector machine (SVM) as a meta-model approach for predicting hydraulic jump characteristics in different sudden diverging stilling basins (i.e. basins with and without appurtenances). In this regard, different models were developed and tested using 1,018 experimental data. The obtained results proved the capability of the SVM technique in predicting hydraulic jump characteristics and it was found that the developed models for a channel with a central block performed more successfully than models for channels without appurtenances or with a negative step. The superior performance for the length of hydraulic jump was obtained for the model with parameters F1 (Froude number) and (h2-h1)/h1 (h1 and h2 are sequent depth of upstream and downstream respectively). Concerning the relative energy dissipation and sequent depth ratio, the model with parameters F1 and h1/B (B is expansion ratio) led to the best results. According to the outcome of sensitivity analysis, Froude number had the most significant effect on the modeling. Also comparison between SVM and empirical equations indicated the great performance of the SVM.
Assuntos
Modelos Teóricos , Engenharia Sanitária/métodos , Máquina de Vetores de Suporte , Movimentos da Água , Algoritmos , Sequência de BasesRESUMO
The shuffled complex evolution optimization developed at the University of Arizona (SCE-UA) has been successfully applied in various kinds of scientific and engineering optimization applications, such as hydrological model parameter calibration, for many years. The algorithm possesses good global optimality, convergence stability and robustness. However, benchmark and real-world applications reveal the poor computational efficiency of the SCE-UA. This research aims at the parallelization and acceleration of the SCE-UA method based on powerful heterogeneous computing technology. The parallel SCE-UA is implemented on Intel Xeon multi-core CPU (by using OpenMP and OpenCL) and NVIDIA Tesla many-core GPU (by using OpenCL, CUDA, and OpenACC). The serial and parallel SCE-UA were tested based on the Griewank benchmark function. Comparison results indicate the parallel SCE-UA significantly improves computational efficiency compared to the original serial version. The OpenCL implementation obtains the best overall acceleration results however, with the most complex source code. The parallel SCE-UA has bright prospects to be applied in real-world applications.
Assuntos
Algoritmos , Modelos Teóricos , Engenharia Sanitária/métodos , SoftwareRESUMO
In recent years, there has been a steady increase in the number of bioretention systems installed worldwide. However, there has only been limited research on the long-term effectiveness of these sustainable urban drainage system devices. This paper presents the results of a series of controlled field experiments investigating the pollutant removal efficiency of three, 10-year-old, bio-filtration systems that have been in service in the Sunshine Coast in Australia. The results of this study suggest that the long-term pollution removal performance of these systems may not be as effective as previously thought and further research is needed.
Assuntos
Engenharia Sanitária/métodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Poluição da Água/prevenção & controle , Austrália , Filtração , Chuva , Áreas AlagadasRESUMO
Hamburg is a growing metropolitan city. The increase in sealed surfaces of about 0.36% per year and the subsequent increased runoff impacts on the city's wastewater infrastructure. Further potential risks to the drainage infrastructure arise also from effects of climate change, e.g. increased intensity and frequency of heavy rainfalls. These challenges were addressed in the Rain InfraStructure Adaption (RISA) project conducted 2009-2015 by HAMBURG WASSER and the State Ministry for Environment and Energy, supported by several municipal stakeholders. RISA addressed intensifying conflicts in the context of urban development and stormwater management at that time. Major results of the project are improvements and recommendations for adequate consideration of stormwater management issues during urban planning as well as new funding mechanisms for stormwater management measures. The latter topic resulted in the introduction of a separated stormwater charge based on the amount of sealed area connected to the sewer system of each property. For both undertakings - the RISA project and the introduction of the separated stormwater charge - a novel, comprehensive, digital database was built. Today, these geographical information system (GIS)-based data offer various scale-independent analysis and information opportunities, which facilitate the day-to-day business of HAMBURG WASSER and stormwater management practice in Hamburg.
Assuntos
Cidades , Planejamento de Cidades , Engenharia Sanitária/economia , Engenharia Sanitária/métodos , Movimentos da Água , Mudança Climática , Meio Ambiente , Monitoramento Ambiental , Sistemas de Informação Geográfica , Alemanha , Chuva , Eliminação de Resíduos Líquidos/métodosRESUMO
The water budget of the Bangkok Metropolis system was analyzed using a material flow analysis model. Total imported flows into the system were 80,080 million m3 per year (Mm3 y-1) including inflows from the Chao Phraya and Mae Klong rivers and rainwater. Total exported flows out of the system were 78,528 Mm3 y-1 including outflow into the lower Chao Phraya River and tap water (TW) distributed to suburbs. Total rates of stock exchange (1,552 Mm3 y-1) were found in the processes of water recycling, TW distribution, domestic use, swine farming, aquaculture, and paddy fields. Only 21% of the total amount of wastewater (1,255 Mm3 y-1) was collected, with insufficient treatment capacity of about 415 Mm3 y-1. Domestic and business (industrial and commercial sectors) areas were major point sources, whereas paddy fields were a major non-point source of wastewater. To manage Bangkok's water budget, critical measures have to be considered. Wastewater treatment capacity and efficiency of wastewater collection should be improved. On-site wastewater treatment plants for residential areas should be installed. Urban planning and land use zoning are suggested to control land use activities. Green technology should be supported to reduce wastewater from farming.
Assuntos
Monitoramento Ambiental/métodos , Engenharia Sanitária/métodos , Águas Residuárias , Abastecimento de Água , Agricultura , Animais , Cidades , Rios , Tailândia , Eliminação de Resíduos LíquidosRESUMO
INTRODUCTION: Saltwater intrusion and salinisation have contributed to drinking water scarcity in many coastal regions globally, leading to dependence on alternative sources for water supply. In southwest coastal Bangladesh, communities have few options but to drink brackish groundwater which has been associated with high blood pressure among the adult population, and pre-eclampsia and gestational hypertension among pregnant women. Managed aquifer recharge (MAR), the purposeful recharge of surface water or rainwater to aquifers to bring hydrological equilibrium, is a potential solution for salinity problem in southwest coastal Bangladesh by creating a freshwater lens within the brackish aquifer. Our study aims to evaluate whether consumption of MAR water improves human health, particularly by reducing blood pressure among communities in coastal Bangladesh. METHODS AND ANALYSIS: The study employs a stepped-wedge cluster-randomised controlled community trial design in 16 communities over five monthly visits. During each visit, we will collect data on participants' source of drinking and cooking water and measure the salinity level and electrical conductivity of household stored water. At each visit, we will also measure the blood pressure of participants ≥20 years of age and pregnant women and collect urine samples for urinary sodium and protein measurements. We will use generalised linear mixed models to determine the association of access to MAR water on blood pressure of the participants. ETHICS AND DISSEMINATION: The study protocol has been reviewed and approved by the Institutional Review Boards of the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). Informed written consent will be taken from all the participants. This study is funded by Wellcome Trust, UK. The study findings will be disseminated to the government partners, at research conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT02746003; Pre-results.