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1.
Waste Manag ; 119: 275-284, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33099072

RESUMEN

Critical high-tech minerals (CHTMs) are raw materials that are essential for a future clean-energy transition and the manufacture of high-end products. Cellphones, one of the fastest growing electronic products, contain various CHTMs. Since 2019, India has surpassed the United States to become the second largest smartphone market in the world. An increasing and alarming number of excessive waste cellphones will be generated in India in the near future. In this study, the dynamic material flow analysis approach and the Weibull distribution are adopted to analyze the volumes of accumulated waste cellphones and the contained CHTMs based on the differentiation between smartphones and feature phones in India. Moreover, a market supply model is adopted to predict the future trends of CHTMs in waste cellphones. The results show a general upward tendency of waste cellphone volume in India, which indicates that various CHTMs contained in cellphone waste can be properly reused or recycled. Future implications based on the analysis results are provided for efficient cellphone management in India.


Asunto(s)
Teléfono Celular , Administración de Residuos , Predicción , India , Minerales , Reciclaje
2.
J Hazard Mater ; 401: 123865, 2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-33113751

RESUMEN

The life cycle impacts of treatment of typical oil-based drill cuttings (OBDCs) using three low-temperature thermal desorption (LTTD)-based systems, including thermomechanical cuttings cleaner (TCC), screw-type dryer (STD), and rotary drum dryer (RDD), were explored with a case study in British Columbia, Canada. Two energy supply scenarios, including diesel generator-based onsite (scenario i) and hydropower-based offsite (scenario ii) treatments, were considered in the assessment. The results show that RDD generated the lowest life cycle impacts in terms of damages to human health, ecosystems, and resources in scenario i. TCC-scenario ii generated the lowest impacts among all assessed cases, suggesting that using renewable energy can greatly reduce the impacts of LTTD-based OBDCs treatment. Also, net environmental benefits could be achieved considering the reuse of recovered oil, and the highest net environmental benefits were obtained in TCC-scenario ii. The process contribution analysis found that thermal desorption process accounted for 80-95 % of impacts in almost all impact categories. Energy consumption contours and linear regression models were also developed to help drilling waste managers estimate the life cycle impacts of using hydropower-driven TCC to treat OBDCs with different water and oil contents.

3.
J Hazard Mater ; : 124570, 2020 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-33223322

RESUMEN

Oil-based drill cuttings (OBDCs) were managed in two scenarios including low-temperature thermal desorption (LTTD) and secure landfill through a case study. The removal of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in OBDCs by LTTD under different conditions was investigated. Probabilistic human health risk assessment was performed to quantify the health risk posed to waste management workers under the two scenarios, while the associated costs were also analyzed. The results show that LTTD at 300 °C for >20 min could remove 96.27% of PAHs in OBDCs but its removal effect on heavy metals was not significant. It was found that cancer risks posed by PAHs in both securely landfilled and LTTD-treated OBDCs were not significant (<1e-06); however, significant cancer risks (7.95e-05-9.45e-05) were identified for exposure to toxic heavy metals. Increased health risk was observed as a result of exposure to LTTD treatment residues compared to securely landfilled OBDCs. Inhalation of chromium(VI) and oral ingestion of arsenic in OBDCs were critical exposure routes. Both cancer and non-cancer risks in the secure landfill scenario were negligible. The cost analysis results suggest that LTTD combined with stabilization/solidification could be more economically attractive than secure landfill for the handling of OBDCs.

4.
Mar Pollut Bull ; 161(Pt A): 111705, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33022490

RESUMEN

A fuzzy decision tree (FDT) based framework was developed to facilitate the selection of suitable oil spill response methods in the Arctic. Hypothetical oil spill cases were developed based on six identified attributes, while the suitability of three spill response methods (mechanical containment and recovery, use of chemical dispersants, and in-situ burning) for each spill case was obtained based on expert judgments. Fuzzy sets were used to address the associated uncertainties, and FDTs were then developed through generating: i) one decision tree for all three response methods (FDT-AP1) and ii) one decision tree for each response method and the development of linear regression models at terminal nodes (FDT-LR). The FDT-LR approach exhibited higher prediction accuracy than the FDT-AP1 approach. A maximum of 100% accurate predictions could be achieved for testing cases using it. On average, 75% of suitable oil spill response methods out of 10,000 performed iterations were predicted correctly.

5.
J Clean Prod ; 271: 122430, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-32834562

RESUMEN

Occupant behavior in residential buildings has a direct impact on the effectiveness of energy-saving measures. In order to realize a buildings' carbon mitigation targets, the impact of individual occupancy profiles needs to be integrated with building simulation models. This paper introduces a decision support framework as a potential solution to make energy performance upgrade choices based on different occupancy profiles. This framework has been demonstrated through a case study of two single-family detached homes in Canada, which were highly instrumented with sensors for monitoring energy input and output. The case studies represented two common occupancy profiles-(1) a family of four (consisting of 2 working adults and 2 teenagers); and (2) a retired couple. Firstly, calibrated energy models were developed by using one-year energy use data collected through an intrusive load monitoring technique. Secondly, energy upgrade combinations were considered for each profile and tested for additional investment, payback period and greenhouse gas (GHG) emissions. Lastly, the most suitable combination of energy upgrade for each profile was ranked using a multi-criteria decision-making method (e.g., TOPSIS). Results indicated that the retired couple used more energy than the family of four and required energy upgrades with usually higher payback periods to achieve the same level of GHG emission reduction. The results of this research are timely for energy policymaking and developing best management practices, which need to be implemented along with the deployment of more stringent building standards and codes.

6.
Environ Monit Assess ; 192(8): 497, 2020 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-32642800

RESUMEN

Disinfection is used to deactivate pathogens in drinking water. However, disinfectants react with natural organic matter present in water to form disinfection by-products (DBPs). While a few of these DBPs have been studied extensively and are regulated in many countries, new unregulated DBPs (UR-DBPs) have also recently been identified in drinking water. The UR-DBPs are considered to be more toxic than regulated DBPs (R-DBPs). To understand the occurrence of UR-DBPs in a water distribution network (WDN), this research presents an approach to predicting the behaviour of emerging UR-DBPs such as dichloroacetonitrile (DCAN), trichloropropanone (TCP), and trichloronitromethane (TCNM) in WDNs. Water quality data, generated by sampling and laboratory analysis of 12 small communities, was used to develop predictive models. A framework was also proposed alongside the predictive models to estimate the concentration of emerging UR-DBPs under limited water quality sampling information. Moreover, the relationship between emerging UR-DBP concentrations and their identified predictors was further observed and evaluated by developing contour profiles. DCAN and TCP predictive models have coefficient of determination (R2) > 85%, whereas for TCNM model, the R2 was > 65%. Water quality parameters including water temperature, turbidity, conductivity, and dissolved organic carbon concentrations were identified as key predictors. Similarly, trichloroacetic acid and bromodichloromethane were identified as key predictors among DBP families, to predict the occurrence of emerging UR-DBPs. Developed models and relationships between the UR-DBPs and predictors can help water utilities and regulators to manage the occurrence of UR-DBPs in small WDNs.


Asunto(s)
Desinfectantes/análisis , Agua Potable/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua , Desinfección , Monitoreo del Ambiente , Halogenación , Agua , Abastecimiento de Agua
7.
Sci Total Environ ; 744: 140778, 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-32717466

RESUMEN

Low Impact Developments (LIDs) employ a series of vegetative techniques to retain rainfall close to the site of origin. Although LIDs offer sustainable runoff management, these infrastructures can be considered a risk to public health due to the presence of pathogens in the runoff and human exposure to contaminated water held in and transported by LIDs. The objective of this study is to examine the disease burden of Gastrointestinal illness (GI) from exposure to LIDs at the residential, neighbourhood, and municipal levels. The authors conducted a meta-analysis of literature on three water features: (1) harvested rainwater obtained from LIDs, (2) surface water, and (3) floodwater. A set of 32 studies were systematically selected to collect values of risks of infection and expressed as the disease burden, i.e. disability adjusted life years (DALYs). The results showed that the percentage of GI illness exceeding the health guidelines were high for harvested rainwater, i.e. 22% of annual disease burden exceeded the WHO guidelines (0.001 DALYs/1000 persons), and 2% exceeded the US EPA guidelines (5.75 DALYs/1000 bathers). Among the six exposures for harvested rainwater, exposure to spray irrigation, exceeded US EPA guidelines whereas; five exposures, i.e. flushing, hosing, daily shower, spray irrigation, and children playing, surpassed the WHO guidelines. Considering LID treatment, the values of annual disease burden from all the selected barriers were below US EPA guidelines however, these values exceeded the WHO guidelines for three barriers i.e. water plaza, grass swale, and open storage ponds. These findings provide a broader perspective of the disease burden associated with LIDs and emphasise to consider the type of exposures and required treatment barriers for developing LID infrastructures in urban areas.


Asunto(s)
Salud Pública , Microbiología del Agua , Niño , Humanos , Años de Vida Ajustados por Calidad de Vida , Medición de Riesgo , Agua
8.
J Environ Manage ; 250: 109514, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31521925

RESUMEN

Heavy metal(loids) in drinking water have long been a critical water quality concern. Chronic exposure to toxic heavy metals and metalloids (TMMs) through water ingestion can result in significant health risks to the public, while elevated concentrations of less toxic heavy metals (LTMs) can compromise the aesthetic value of water. An integrated probabilistic-fuzzy approach was developed to help water utilities assess water quality regarding heavy metal(loids) (WQHM). In probabilistic assessments, the probabilities of exceedance of health risk guidelines due to chronic exposure to TMMs and exceedance of aesthetic objectives due to elevated LTMs concentrations were quantified through Monte Carlo simulations. The probabilistic assessments can address the aleatory uncertainties due to random variations of health risk parameters. A fuzzy inference system, composed of fuzzy membership functions, operators, and rules, was used to facilitate interpreting WQHM based on the probabilities of guideline exceedance. Epistemic uncertainties due to vagueness and imprecision in linguistic variables used for describing health risks and aesthetic impacts can be reduced by fuzzy inferencing. The developed approach was applied to four water quality scenarios characterized by different combinations of TMMs and LTMs concentrations. Reasonable decisions were recommended for WQHM management under the four scenarios. The developed approach offers a useful tool for systematically assessing WQHM from a health risk mitigation perspective by addressing different types of uncertainties.


Asunto(s)
Agua Potable , Metales Pesados , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Medición de Riesgo , Incertidumbre , Calidad del Agua
9.
Water Res ; 161: 89-97, 2019 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-31181450

RESUMEN

To discover an applicable technology for urea abatement from swimming pool water (SPW), this study compared the performances of seven ultraviolet (UV)-based technologies on urea removal, including UV alone, UV coupled with hydrogen peroxide (UV/H2O2), sulfite (UV/Na2SO3), potassium persulfate (UV/K2S2O8), a combination of UV and vacuum UV (UV/VUV), and UV/VUV in tandem with either H2O2 (VUV/H2O2) or potassium persulfate (VUV/K2S2O8). Among them, UV and UV/Na2SO3 showed little removal ability, and UV/H2O2 removed only 12.8% of urea within 3-h experiments, while UV/VUV degraded 71.7% of urea without introducing substantial total dissolved solids (TDS). Therefore, UV/VUV was considered as a promising technology for further exploration. In comparison, although UV/K2S2O8 exhibited higher urea removal than UV/VUV, it caused dramatic increases of TDS, which made the regulatory threshold for the TDS increment difficult to maintain. Within UV/VUV studies, some common components in SPW (e.g., cyanuric acid, humic acid, nitrate, and bicarbonate) inhibited the removal process, whereas chloride and sulfate facilitated it, while free chlorine at doses ≤ 3 mg-Cl2/L and pH levels from 6.8 to 8.0 imposed little impact on urea degradation. Overall, UV/VUV degraded 40.0% and 22.2% of urea from tap water and SPW, respectively; both were lower than the efficiency observed in ultrapure water. As for reaction byproducts, urea phototransformation via UV/VUV yielded nitrate and ammonia as the key products with the mass balance of nitrogen element being met. However, the contents of organic carbon decreased at a rate slightly lower than urea degradation, suggesting that urea was mostly mineralized and slightly converted to unknown organic compounds. The results hence demonstrate that UV/VUV is an effective alternative for urea removal from SPW.


Asunto(s)
Piscinas , Contaminantes Químicos del Agua , Purificación del Agua , Peróxido de Hidrógeno , Oxidación-Reducción , Fotólisis , Rayos Ultravioleta , Urea
10.
J Safety Res ; 68: 59-69, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30876521

RESUMEN

INTRODUCTION: The safety of oil and gas pipelines is an increasing concern for the public, government regulators, and the industry. A safety management system cannot be efficient without having an effective integrity management program (IMP) and a strong safety culture. IMP is a formal document (policies, planning, scheduling, and technical processes) while safety culture is a measure of views, beliefs, and traditions about safety. For regulatory authorities and O&G companies, assessing the effectiveness of both the IMP and safety culture through regulatory audits is a daunting task with indistinct findings. METHOD: An integrated framework based on regulatory audits is developed to assess the maturity of safety culture based on IMP efficacy through risk-based approach by using failure mode and effect analysis (FMEA). The framework focuses on three distinct aspects, the probability of failure occurrence in case of the non-compliance of regulatory and program requirements, severity of non-compliance, and effectiveness of the corrective actions. RESULTS: Program requirements and performance indicators are translated into assessment questions which are grouped into 18 IMP components. Subsequently, these components are linked with four safety culture attributes. Sensitivity analysis revealed that four IMP components, i.e., organizational roles and responsibilities, policy and commitment, risk assessment, and training and competency, significantly affect the safety culture maturity level. CONCLUSIONS: Individual assessment of IMP and safety culture in O&G sector consumes extensive time and efforts in the auditing process. The framework facilitates the process by pursuing common criteria between IMP and safety culture. The O&G companies and regulator can prioritize the improvement plans and guidelines using the framework's findings. Practicalapplications: The integrated framework developed in this research will improve the existing assessment mechanism in O&G companies. The framework has been effectively implemented on a case of 17 upstream O&G pipeline-operating companies in the province of British Columbia, Canada.


Asunto(s)
Regulación Gubernamental , Medición de Riesgo/métodos , Administración de la Seguridad , Colombia Británica , Humanos , Método de Montecarlo , Gas Natural , Cultura Organizacional , Petróleo , Evaluación de Programas y Proyectos de Salud
11.
J Environ Manage ; 235: 389-402, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30708276

RESUMEN

The use of Low Impact Development (LID) alternatives requires the establishment of appropriate regulations and guidelines on acceptable practices and developing consensus among stakeholders, thus assuring the rights of all water-users and for conflict resolution. This content analysis aims to examine whether stormwater regulations and guidelines have addressed the use of LID alternatives in urban settings and compares the current state of regulations in the context of Canadian provinces and territories., A list of eight core criteria relevant to the implementation of LID has been identified and an ordinal scale ranging from 1 to 6 is proposed to track the progress towards LID-friendly regulations in each province. Furthermore, based on comparative assessment, Canadian provinces are categorized into three groups: 'highly, moderately, and slightly LID-friendly' to project a broad view of the current state of regulations required to promote LID alternatives. . Results show that LID has become the mainstream technology for stormwater management in Alberta, British Columbia, Ontario, and Quebec, which are categorized as 'highly LID-friendly' provinces. The provinces where LID alternatives have gained considerable acceptance are categorized as 'moderately LID-friendly', which include Manitoba, Newfoundland and Labrador, Nova Scotia, Prince Edward Island, and Saskatchewan. Lastly, the province of New Brunswick is categorized as 'slightly LID-friendly', because of very limited use of LID alternatives in the stormwater management regulations. These findings of this content analysis can be of significant value to strengthen provincial/territorial regulations and extend the benefits of LID in stormwater quality management and sustainable water management.


Asunto(s)
Conservación de los Recursos Naturales , Abastecimiento de Agua , Alberta , Colombia Británica , Canadá , Terranova y Labrador , Ontario , Quebec , Lluvia
12.
Sci Total Environ ; 651(Pt 1): 775-786, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30253359

RESUMEN

Disinfection by-products (DBPs) in indoor swimming pool water and air have long been a critical human health risk concern. This study investigated the effects of several indoor swimming pool design and management factors (e.g. ventilation, water treatment, pool operations, pool type) on the concentrations of DBPs, such as trihalomethanes (THMs) and chloramines, in pool water and air. Two sampling campaigns, A and B, were carried out to measure the concentrations of DBPs under different conditions. In both campaigns, 46 pool water samples, seven tap water samples, and 28 ambient air samples were collected and analyzed. Regression models were also developed and validated for investigating the combined effects of design and management factors on total trihalomethanes (TTHM) and trichloramine. The model results show that pool water characteristics (e.g., total organic content, temperature, conductivity, pH and alkalinity) and management factors (e.g., the number of bathers and sprayers) have direct effects on DBP concentrations. Pool water characteristics such as UV absorbance, hardness, and oxidation-reduction potential and a management factor UV intensity have inverse effects on DBPs levels. Based on the correlation analysis, other factors such as fan speed, fresh air, pool age, and basin area were found to be correlated with the concentrations of individual THMs and trichloramine in both water and air. It was also observed that the concentration of THMs varies with pool type. It is note worthy that the effects of the number of sprayers was quantified for the first time. This study comprehensively assessed pool design and management factors and identified their effects on DBPs, providing indoor swimming pool facilities with useful information to control DBPs in the indoor swimming environment.

13.
Sci Total Environ ; 650(Pt 2): 2512-2526, 2019 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-30373046

RESUMEN

Globally the trend of water reuse has been increasing. The public perception and government regulations are supportive for reclaimed water use in Canada. Reclaimed water can be used in variety of applications that may have different performance in economic, environmental and social dimensions for various stakeholders, indicating decision on water reuse selection is complex. This research proposes a multi-criteria multi-decision-makers framework combining multicriteria decision analysis (MCDA) and game theory for a selection of a sustainable water reuse application. The proposed framework is applied to the City of Penticton, BC, Canada. The evaluation criteria included were environmental: fresh water saving, energy use, and carbon emissions; economic: annualized life cycle cost; and social: government policy, public perception, and human health risk for three stakeholders: municipality, citizens, and farm operators. The game theory is applied to eight water reuse options considering a cooperative game. The result shows that lawn, golf course and public park irrigation and toilet flushing with an equal sharing of municipal benefits between the municipality and citizens is the optimal solution. By using the solution, the municipality can have an additional saving of approximately $35/household/year and the citizens have to spend an additional amount of approximately $100/household/year for dual plumbing of toilet and lawn for reclaimed water use. The additional expenditure for the citizens is within Canada's public willingness to pay an additional charge for reclaimed water use. The scenario analysis shows that the weights of sustainability criteria are important in decision-making. Also, the sensitivity analysis shows that the change in the amount of reclaimed water availability can affect water reuse sustainability performance. The proposed framework can also be used in other applications by changing the number of evaluation criteria and stakeholders as required.

14.
Water Res ; 147: 112-131, 2018 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-30308371

RESUMEN

Water disinfection involves the use of different types of disinfectants, which are oxidizing agents that react with natural organic matter (NOM) to form disinfection by-products (DBPs). The United States Environmental Protection Agency (USEPA) has established threshold limits on some DBPs, which are known as regulated DBPs (R-DBPs). The human health risks associated with R-DBPs in drinking water distribution systems (DWDSs) and application of stricter regulations have led water utilities to switch from conventional disinfectant (i.e., chlorination) to alternative disinfectants. However, the use of alternative disinfectants causes formation of a new suit of DBPs known as unregulated DBPs (UR-DBPs), which in many cases can be more toxic. There is a growing concern of UR-DBPs formation in drinking water. This review prioritizes some commonly occurring UR-DBP groups and species in DWDSs based on their concentration level, reported frequency, and toxicity using an indexing method. There are nine UR-DBPs group and 36 species that have been identified based on recent published peer-reviewed articles. Haloacetonitriles (HANs) and haloacetaldehydes (HALs) are identified as important UR-DBP groups. Dichloroacetonitrile (DCAN) and trichloroacetaldehye (TCAL) are identified as critical UR-DBPs species. The outcomes of this review can help water regulators to identify the most critical UR-DBPs species in the context of drinking water safety and provide them with useful information to develop guidelines or threshold limits for UR-DBPs. The outcomes can also help water utilities in selecting water treatment processes for the mitigation of human health risk posed by UR-DBPs through drinking water.


Asunto(s)
Desinfectantes , Agua Potable , Contaminantes Químicos del Agua , Purificación del Agua , Desinfección , Halogenación , Humanos
15.
J Environ Manage ; 223: 984-1000, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30096751

RESUMEN

Disinfection by-products (DBPs) are formed primarily by the reaction of natural organic matter and disinfectants. DBPs that are not regulated are referred to as unregulated DBPs (U-DBPs) and they are in majority in total DBPs. U-DBPs can be more toxic than regulated DBPs. U-DBPs such as haloacetonitriles (HANs), haloacetonitriles (HKs) and halonitromethanes (HNMs) are widely present in drinking water supplies in different regions of the world. This study investigated the occurrence of U-DBPs and their variability in drinking water in the Province of Quebec (Canada), using the water quality database of 40 municipal water systems generated by our research group. The concentrations of HANs, HKs, and their compounds, including chloropicrin (CPK), were highly variable in different water systems in Quebec. The concentration range of these U-DBPs is in line with drinking water concentration ranges in different regions of the world. Factors such as system size, water source, season, pH, total organic carbon content, free residual chlorine and disinfectant types cause significant variations in the concentrations of HANs, HKs and their constituent compounds, including CPK, in drinking water in Quebec. This information is valuable for decision making concerning source water selection, water distribution planning, water treatment plant design including disinfection, and overall drinking water quality management related to U-DBPs. Moreover, U-DBPs and regulated DBPs are strongly correlated, although the degree of correlation can vary with water source, system size and season, indicating that regulated DBPs can be used as surrogates of U-DBPs.


Asunto(s)
Desinfección , Agua Potable , Purificación del Agua , Canadá , Desinfectantes , Quebec , Contaminantes Químicos del Agua , Abastecimiento de Agua
16.
Sci Total Environ ; 619-620: 281-290, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29149752

RESUMEN

The rapid expansion of unconventional natural gas production has triggered considerable public concerns, particularly regarding environmental and human health (EHH) risks posed by various chemical additives used in hydraulic fracturing (HF) operations. There is a need to assess the potential EHH hazards of additives used in real-world HF operations. In this study, HF additive and fracturing fluid data was acquired, and EHH hazards were assessed using an indexing approach. The indexing system analyzed chemical toxicological data of different ingredients contained within additives and produced an aggregated EHH safety index for each additive, along with an indicator describing the completeness of the chemical toxicological data. The results show that commonly used additives are generally associated with medium-level EHH hazards. In each additive category, ingredients of high EHH concern were identified, and the high hazard designation was primarily attributed to ingredients' high aquatic toxicity and carcinogenic effects. Among all assessed additive categories, iron control agents were identified as the greatest EHH hazards. Lack of information, such as undisclosed ingredients and chemical toxicological data gaps, has resulted in different levels of assessment uncertainties. In particular, friction reducers show the highest data incompleteness with regards to EHH hazards. This study reveals the potential EHH hazards associated with chemicals used in current HF field operations and can provide decision makers with valuable information to facilitate sustainable and responsible unconventional gas production.

17.
Environ Monit Assess ; 189(9): 464, 2017 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-28836091

RESUMEN

Traditional approaches for benchmarking drinking water systems are binary, based solely on the compliance and/or non-compliance of one or more water quality performance indicators against defined regulatory guidelines/standards. The consequence of water quality failure is dependent on location within a water supply system as well as time of the year (i.e., season) with varying levels of water consumption. Conventional approaches used for water quality comparison purposes fail to incorporate spatiotemporal variability and degrees of compliance and/or non-compliance. This can lead to misleading or inaccurate performance assessment data used in the performance benchmarking process. In this research, a hierarchical risk-based water quality performance benchmarking framework is proposed to evaluate small drinking water systems (SDWSs) through cross-comparison amongst similar systems. The proposed framework (R WQI framework) is designed to quantify consequence associated with seasonal and location-specific water quality issues in a given drinking water supply system to facilitate more efficient decision-making for SDWSs striving for continuous performance improvement. Fuzzy rule-based modelling is used to address imprecision associated with measuring performance based on singular water quality guidelines/standards and the uncertainties present in SDWS operations and monitoring. This proposed R WQI framework has been demonstrated using data collected from 16 SDWSs in Newfoundland and Labrador and Quebec, Canada, and compared to the Canadian Council of Ministers of the Environment WQI, a traditional, guidelines/standard-based approach. The study found that the R WQI framework provides an in-depth state of water quality and benchmarks SDWSs more rationally based on the frequency of occurrence and consequence of failure events.


Asunto(s)
Agua Potable/normas , Monitoreo del Ambiente/métodos , Modelos Teóricos , Calidad del Agua , Abastecimiento de Agua/normas , Benchmarking , Lógica Difusa , Regulación Gubernamental , Terranova y Labrador , Quebec , Medición de Riesgo , Estaciones del Año , Análisis Espacio-Temporal , Abastecimiento de Agua/legislación & jurisprudencia
18.
Sci Total Environ ; 607-608: 403-412, 2017 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-28700973

RESUMEN

This paper is the second in a series of two papers. In Paper I, a decision support tool (DST), FitWater, was developed for evaluating the potential of wastewater treatment (WWT) trains for various water reuse applications. In the present paper, the proposed DST has been tested and implemented. FitWater has been tested with several existing WWT plants in Canada and the USA, demonstrating FitWater's effectiveness in estimating life cycle cost (LCC), health risk, and energy use. FitWater has also been implemented in a newly planned neighbourhood in the Okanagan Valley (BC, Canada) by developing 12 alternative WWT trains for water reuse in lawn and public parks irrigation. The results show that FitWater can effectively rank WWT train alternatives based on LCC, health risk, amount of reclaimed water, energy use, and carbon emissions. Moreover, functions have been developed for the variation of unit annualized LCC and energy intensity per unit log removal of microorganisms in different treatment technologies with varying plant capacities. The functions have power relations, showing the economies of scale. FitWater can be applied to identify a cost-effective, risk-acceptable, and energy efficient wastewater treatment train with a plant capacity of 500m3/day or more. Furthermore, FitWater can be used to assess potential economic impacts of developing microbiologically stringent effluent standards. The capability of FitWater can be enhanced by including physio-chemical quality of wastewater, additional treatment technologies, and carbon emissions from wastewater decomposition processes.

19.
Sci Total Environ ; 607-608: 600-612, 2017 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-28709094

RESUMEN

This article is the first in a series of two papers. Paper I focuses on model conceptualization and development, and Paper II in the series focuses on model validation and implementation. The amount of water reuse has been increasing across the globe. Wastewater can be treated based on the intended end use of reclaimed water. Fit-for-purpose wastewater treatment (WWT) simultaneously considers intended end use, economic viability, and environmental sustainability. WWT technologies differ mainly in terms of treatment efficiency, cost, energy use, and associated carbon emissions. The planning and evaluation of water reuse projects requires a decision support tool (DST) to evaluate alternative WWT trains and water reuse applications. However, such a DST is not available in the publically accessible literature. A DST, FitWater, has been developed for the evaluation of WWT for various urban reuses. The evaluation is based on the following criteria: amount of reclaimed water production, health risk of water reuse, cost, energy use, and carbon emissions. The cost is estimated as annualized life cycle cost and health risk is estimated using quantitative microbial risk assessment. The uncertainty analysis has been performed using probabilistic and fuzzy-based methods. A multi-criteria decision analysis, using fuzzy weighted average, is employed to aggregate different criteria and generate a final score. FitWater ranks alternative WWT trains based on the resulting final score. The proposed FitWater DST is user-friendly, and its application is demonstrated using an example. The DST can be enhanced to include additional treatment technologies and carbon emissions of different treatment processes.

20.
Environ Monit Assess ; 189(7): 307, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28573352

RESUMEN

Managing residual chlorine in large water distribution systems (WDS) to minimize human health risk is a daunting task. In this research, a novel risk-based framework is developed and implemented in a distribution network spanning over 64 km2 for supplying water to the city of Al-Khobar (Saudi Arabia) through 473-km-long water mains. The framework integrates the planning of linear assets (i.e., pipes) and placement of booster stations to optimize residual chlorine in the WDS. Failure mode and effect analysis are integrated with the fuzzy set theory to perform risk analysis. A vulnerability regarding the probability of failure of pipes is estimated from historical records of water main breaks. The consequence regarding residual chlorine availability has been associated with the exposed population depending on the land use characteristics (i.e., defined through zoning). EPANET simulations have been conducted to predict residual chlorine at each node of the network. A water quality index is used to assess the effectiveness of chlorine practice. Scenario analysis is also performed to evaluate the impact of changing locations and number of booster stations, and rehabilitation and/or replacement of vulnerable water mains. The results revealed that the proposed methodology could facilitate the utility managers to optimize residual chlorine effectively in large WDS.


Asunto(s)
Cloro/análisis , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Abastecimiento de Agua , Humanos , Iones , Riesgo , Arabia Saudita , Microbiología del Agua , Calidad del Agua
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