contaminant modeling Articles
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Use of a three-dimensional model to predict heavy metal (copper) fluxes in the Oujiang estuary
Measuring pollutant concentrations in major tributaries is the standard method for establishing pollutant fluxes to the sea. However, this method is costly and difficult, and may be subject to a great deal of uncertainty due to the presence of unknown sources. This uncertainty presents challenges to managers and scientists in reducing contaminant discharges to water bodies. As one less costly ...
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The mathematical modelling of total nitrogen contamination transport via groundwater from a sugar factory in Eskisehir, Turkey
In this study, mathematical modelling of the total nitrogen contamination transport in a porous medium was evaluated in order to determine the potential groundwater pollution caused by a sugar factory in the Eskisehir region of Turkey. Analytical solutions of mathematical modelling were performed to show graphically the distributions of contaminant concentrations. Multiflow computer programming ...
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Effect of pH on selective decomposition of target water contaminants onto porous TiO2 photocatalyst
Non-selectivity of TiO2-based photocatalysis is a known drawback of this technology for full scale water treatment applications. It results in significant decline in decomposition of toxic target contaminants when other non-toxic organic compounds such as natural organic matter (NOM) compete in the reaction. Previously, size exclusion of large NOM onto the mesoporous structure of TiO2 ...
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A conceptual decomposition of MINLP models for the design of water-using systems
The work presents a systematic methodology for the design of industrial water systems that combines principles of water-pinch (Wang and Smith, 1994a, 1994b) with mathematical programming techniques that enable the imposition of practical constraints and the generalisation of the conceptual tools into multi-contaminant problems. A superstructure model is formulated as an MINLP and solved via ...
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Developing a public information and engagement portal of urban waterways with real-time monitoring and modeling
Waterways can contribute to the beauty and livelihood of urban areas, but maintaining their hydro-ecosystem health is challenging because they are often recipients of contaminated water from stormwater runoff and other discharges. Public awareness of local waterways’ health and community impacts to these waterways is usually poor due to of lack of easily available information. To improve ...
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Comparison of two multivariate classification models for contamination event detection in water quality time series
This paper explores two applied classification models alerting for contamination events in water distribution systems. The models perform multivariate analysis of water quality online measurements for event detection. The developed models comprise an outlier detection algorithm and a following sequence analysis for the classification of events. The first model is an unsupervised minimum volume ...
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Computational fluid dynamics modeling of contaminant mixing at junctions for an online security management toolkit in water distribution networks
The accurate modeling and simulation of the spread of contaminants within water distribution networks (WDNs) is an important task for drinking water security. In commonly used water quality simulation platforms the mixing of concentrations at junctions is assumed to be a complete mixing behavior. Experimental investigations have shown that this assumption is only true for certain flow ...
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Quantifying uncertainty in the trophic magnification factor related to spatial movements of organisms in a food web
Trophic magnification factors (TMFs) provide a method of assessing chemical biomagnification in food webs and are increasingly being used by policy makers to screen emergent chemicals. Recent reviews have encouraged the use of bioaccumulation models as screening tools for assessing TMFs for emergent chemicals of concern. The present study used a food web bioaccumulation model to estimate TMFs ...
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Potential health implications of water resources depletion and sewage discharges in the Republic of Macedonia
Potential health implications of deficient sanitation infrastructure and reduced surface water flows due to climate change are examined in the case study of the Republic of Macedonia. Changes in surface water flows and wastewater discharges over the period 1955–2013 were analyzed to assess potential future surface water contamination trends. Simple model predictions indicated a decline in ...
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A geo-referenced modeling environment for ecosystem risk Assessment: Organophosphate pesticides in an agriculturally dominated watershed
Received for publication May 5, 2008. A geo-referenced modeling system was developed in this study to investigate the spatiotemporal variability of pesticide distributions and associated ecosystem risks. In the modeling system, pesticide fate and transport processes in soil-canopy system were simulated at field scale by the pesticide root zone model (PRZM). Edge-of-field mass fluxes were ...
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Modeling metal bioaccumulation and tissue distribution in killifish (Fundulus heteroclitus) in three contaminated estuaries
The present study experimentally assessed the uptake, loss, and resulting tissue distribution of As(V), Cd, Cr(III), Hg(II), and methylmercury (MeHg) in killifish (Fundulus heteroclitus) following aqueous exposure in water collected from 3 contaminated field sites—Baltimore Harbor and Elizabeth River (Chesapeake Bay), and Mare Island (San Francisco Bay)—using a radiotracer technique. Uptake ...
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Decision support system for risk management of produced water in offshore oil and gas industries
A decision support system for produced water management (DISSPROWM) in offshore operations is presented. The system determines the risk and hazards to human and marine species from non-carcinogenic and carcinogenic pollutants present in produced water including radionuclides. The DISSPROWM also evaluates best available treatment technology for treating the produced water whose properties are in ...
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Climate conditions and consequences for de-icing operations as exemplified by the situation on a motorway and airport at Gardermoen, Norway
Large amounts of de-icing chemicals are used in the northern hemisphere to maintain winter safety on roads and airports every year. At Gardermoen, potassium formate (KFo) is used on runways, sodium chloride (NaCl) on roads and propylene glycol (PG) for aeroplanes. The total use of de-icing chemicals is an important part of the risk assessment related to water contamination at Gardermoen. The ...
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Modeling of coastal water contamination in Fortaleza (Northeastern Brazil)
An important tool in environmental management projects and studies due to the complexity of environmental systems, environmental modeling makes it possible to integrate many variables and processes, thereby providing a dynamic view of systems. In this study the bacteriological quality of the coastal waters of Fortaleza (a state capital in Northeastern Brazil) was modeled considering multiple ...
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Integrated conceptual modelling of faecal contamination in an urban estuary catchment
Urban stormwater is regarded as a key input of faecal contamination in receiving water bodies and therefore, a major concern for health risks associated with aquatic recreation. Wastewater leakages, cross connections and overflows, together with faeces washed from surfaces during rainfall events, are possible origins of faecal contamination which enter these water bodies through stormwater ...
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Integrating evolution strategies and genetic algorithms with agent-based modeling for flushing a contaminated water distribution system
Water utilities can prepare for water distribution hazards, such as the presence of contaminants in the pipe network and failure of physical components. In contamination events, the complex interactions among managers' operational decisions, consumers' water consumption choices, and the hydraulics and contaminant transport in the water distribution system may influence the ...
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Design of dual water supply system using rainwater and groundwater at arsenic contaminated area in Vietnam
Fresh water, a renewable but limited resource, is scarce in many areas of the developing world. This paper proposes a dual water supply consisting of both rainwater and groundwater to provide sustainable water for an arsenic contaminated area. In this paper, a novel model has been developed based on rainfall variance. A rainwater harvesting (RWH) system can obtain optimal performance by ...
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The application of computational fluid dynamics and small-scale physical models to assess the effects of operational practices on the risk to public health within large indoor swimming pools
Swimming pools provide an excellent facility for exercise and leisure but are also prone to contamination from microbial pathogens. The study modelled a 50-m × 20-m swimming pool using both a small-scale physical model and computational fluid dynamics to investigate how water and pathogens move around a pool in order to identify potential risk spots. Our study revealed a number of lessons for ...
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Quantitative microbial risk assessment applied to irrigation of salad crops with waste stabilization pond effluents
A quantitative microbial risk assessment model for estimating infection risks arising from consuming crops eaten raw that have been irrigated with effluents from stabilization ponds was constructed. A log-normal probability distribution function was fitted to a large database from a comprehensive monitoring of an experimental pond system to account for variability in Escherichia coli ...
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State-wide collection of site remediation data in support of environmental quality objectives
Geographic Information Systems (GIS) hold great potential as a tool for managing environmental site remediation data. While noting the location of contaminated sites in GIS is commonplace, GIS has played only a minor role in review and analysis of chemical data gathered during an investigation or monitoring activity. The New Jersey Department of Environmental Protection Site Remediation Branch ...
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