RESUMO
Introduction: Access to safe drinking water is essential to health, and it is a basic human right. However, drinking water treatment plant efficiency and its water quality are not well investigated in low-income countries including Ethiopia. Methods: A laboratory-based cross-sectional study was conducted among 75 water samples. Data analysis was carried out using SPSS version 22 to generate descriptive statistics, and one-way ANOVA was used to test statistically significant difference. Results: Physicochemical qualities of the water samples from tap water sources were found to be pH (6.88 ± 0.05), turbidity (5.15 ± 0.006 NTU), electrical conductivity (170.6 ± 0.1 µS/cm), residual chlorine (0.19 ± 0.003 mg/L), and fluoride (1.17 ± 0.009 mg/L). The removal efficiency of turbidity, total hardness, and nitrate was found to be 94.4%, 52.3%, and 88.7%, respectively. Removal efficiency of the treatment plant for total coliforms up to 91.6% (15 ± 0.26 CFU/100 mL in tap water) and faecal coliforms up to 99% (1.51 ± 0.03 CFU/100 mL in tap water) was recorded. Parameters of pH, temperature, and faecal coliform were statistically significant different at p < 0.05 in tap water source. The overall efficiency of the treatment plant (68.5%) and the water quality index (76) were recorded. Conclusion: Based on the results, some of the investigated parameters of water quality (turbidity, residual chlorine, total coliform, and faecal coliform) were found to be not within the permissible limits of WHO guideline values for drinking water quality. The water quality index of the water samples was categorized under good water quality. To adequately treat drinking water and improve the treatment plant, adequate preliminary treatments like screening to reduce the incoming organic loading, proper chlorination of the drinking water system, and frequent monitoring and maintenance of the treatment plant system are required.
Assuntos
Água Potável , Purificação da Água , Qualidade da Água , Estudos Transversais , Água Potável/análise , Água Potável/normas , Etiópia , Características da Família , Humanos , Purificação da Água/normas , Qualidade da Água/normas , Abastecimento de ÁguaRESUMO
This study evaluated the level of the contaminant of the heavy metals in sludge from different sources and the ecological risk criteria associated with it was also analyzed to establish its reuse in agriculture. The sludge samples were collected from the water plant (WTP), wastewater treatment plant (WWTP), and industrial water treatment plant (IPT) in Taiwan. The inductively coupled plasma mass spectrometry was used to measure the trace metals in sludge. The pollution level and ecological risk criteria for heavy metals in sludge were also used to evaluate its reuse in agriculture. The result shows the average concentrations of trace metals in sludge for three groups (WTP, WWTP, and ITP). Significant correlations were found between concentrations of Zn-Ag (p < 0.001). The higher values of Igeo showed in ITP, indicated Hg to be a major pollutant. In Taiwan, the regulations did not establish the reuse of sludge in agriculture. However, the concentration level of trace metals in sludge was particularly lower than the regular levels in most groups, like WTP and WWTP groups. The industrial sludge was not recommended for the use in agriculture. The results of this study can be used for regular monitoring to establish a reference for sludge management and application to agriculture.
Assuntos
Metais Pesados/análise , Esgotos/química , Oligoelementos/análise , Poluentes Químicos da Água/análise , Irrigação Agrícola/normas , Monitoramento Ambiental , Medição de Risco , Taiwan , Purificação da Água/normasRESUMO
BACKGROUND: Access to safe water for drinking and domestic activities remains a challenge in emerging economies like South Africa, forcing resource-limited communities to use microbiologically polluted river water for personal and household purposes, posing a public health risk. This study quantified bacterial contamination and the potential health hazards that wastewater treatment plant (WWTP) workers and communities may face after exposure to waterborne pathogenic bacteria in a WWTP and its associated surface water, respectively. RESULTS: Escherichia coli (Colilert®-18/ Quanti-Tray® 2000) and enterococci (Enterolert®/ Quanti-Tray® 2000) were quantified and definitively identified by real-time polymerase chain reaction targeting the uidA and tuf genes, respectively. An approximate beta-Poisson dose-response model was used to estimate the probability of infection (Pi) with pathogenic E. coli. Mean E. coli concentration ranged from 2.60E+ 02/100 mL to 4.84E+ 06/100 mL; enterococci ranged from 2.60E+ 02/100 mL to 3.19E+ 06/100 mL across all sampled sites. Of the 580 E. coli isolates obtained from this study, 89.1% were intestinal, and 7.6% were extraintestinal pathogenic E. coli. The 579 enterococci obtained were 50.4% E. faecalis (50.4%), 31.4% E. faecium, 3.5%, E. casseliflavus and 0.7% E. gallinarum. The community health risk stemming from the use of the water for recreational and domestic purposes revealed a greater health risk (Pi) from the ingestion of 1 mL of river water from upstream (range, 55.1-92.9%) than downstream (range, 26.8-65.3%) sites. The occupational risk of infection with pathogenic E. coli for workers resulting from a once-off unintentional consumption of 1 mL of water was 0% (effluent) and 23.8% (raw influent). Multiple weekly exposures of 1 mL over a year could result in a Pi of 1.2 and 100% for the effluent and influent, respectively. CONCLUSION: Our findings reveal that there is a potentially high risk of infection for WWTP workers and communities that use river water upstream and downstream of the investigated WWTP.
Assuntos
Águas Residuárias/microbiologia , Purificação da Água/estatística & dados numéricos , Enterococcus/classificação , Enterococcus/genética , Enterococcus/isolamento & purificação , Enterococcus/patogenicidade , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Medição de Risco , Rios/microbiologia , África do Sul , Purificação da Água/normasRESUMO
Poor water quality exacerbates multidimensional poverty in developing nations. Often centralized treatment facilities generate acceptable water quality, but the water is contaminated during distribution. Methods to assess sources of contamination in water distribution systems are lacking. A case study of two methods, human risk assessment linked to water distribution system sampling was conducted in Hyderabad, Pakistan to determine areas requiring infrastructure rehabilitation. Water samples from source water (i.e., the Indus River), treatment plant effluent and from taps in the water distribution system were analyzed by atomic adsorption spectroscopy for metals and metalloids (As, Cd, Cr, Hg, and Pb) and water quality parameters (dissolved and suspended solids, pH, conductivity, and total organic carbon). Source water exceeded acceptable drinking water levels for As, Cd, total Cr, and Pb, while the treatment plant effluent concentrations were acceptable. Concentrations of all metals and metalloids, except Hg, increased in the water distribution system post-treatment, exceeding safe drinking limits in at least one location, suggesting contamination of the water during distribution. A deterministic and a probabilistic risk assessment were conducted to evaluate two scenarios: (1) unrestricted use of piped water for all household purposes, including as drinking water and (2) restricted use of the water for purposes other than drinking in the household, including only dermal and inhalation exposure pathways. The water was deemed unsafe for unrestricted use as the sole source of drinking water by both risk assessment methods. Yet when an alternative source of drinking water was assumed and the piped water was used only for bathing and dish washing, the probabilistic risk assessment revealed acceptable health risks to the population, while the overly conservative deterministic risk assessment suggested unacceptable risks. The combined methods of water sampling, risk assessment and correlation analysis suggested areas for rehabilitation of the water distribution system in Hyderabad, Pakistan and these methods can be adopted in other developing nations to target limited funds for infrastructure rehabilitation.
Assuntos
Água Potável/análise , Metaloides/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Purificação da Água/normas , Abastecimento de Água/normas , Água Potável/normas , Monitoramento Ambiental/métodos , Humanos , Paquistão , Medição de Risco , Rios/química , Qualidade da Água/normasRESUMO
Various approaches are used to measure the firms' performance. Grey relational analysis is one of the multiple attribute decision-making methods and data envelopment analysis is used to calculate the efficiency. Regarding the importance of water and wastewater companies' services, the present study, evaluates the performance and rank these companies by using grey relational analysis and data envelopment analysis approaches based on balanced scorecard criteria. Besides, balanced scorecard considers all levels of organization. In this research, statistical population includes thirty-five municipal water and wastewater companies in Iran for the year 2017. In order to ascertain grey relational grade, fuzzy normalization method was used then by subtracting normalized numbers from one, reference sequences obtained and in the next step, grey relational coefficient was calculated and finally, grey relational grade was determined by multiplying relative weight from Shannon entropy to relational coefficients. In order to assess companies' efficiency in data envelopment analysis, after ascertaining input and output indices, with the assumption of constant returns to scale and output-oriented viewpoint, the efficiency scores were calculated. Also, to rank efficient units Anderson-Petersen model implemented. Results demonstrated that, grey relational analysis is a more accurate method to measure the performance of water and wastewater companies.
Assuntos
Benchmarking/organização & administração , Avaliação de Programas e Projetos de Saúde/métodos , Purificação da Água/métodos , Abastecimento de Água/métodos , Tomada de Decisões , Humanos , Irã (Geográfico) , Estudos de Casos Organizacionais , Purificação da Água/economia , Purificação da Água/normas , Abastecimento de Água/economia , Abastecimento de Água/normasRESUMO
BACKGROUND: Poor water sanitation and hygiene (WASH) in health care facilities increases hospital-associated infections, and the resulting greater use of second-line antibiotics drives antimicrobial resistance. Recognising the existing gaps, the World Health Organisations' Water and Sanitation for Health Facility Improvement Tool (WASH-FIT) was designed for self-assessment. The tool was designed for small primary care facilities mainly providing outpatient and limited inpatient care and was not designed to compare hospital performance. Together with technical experts, we worked to adapt the tool for use in larger facilities with multiple inpatient units (wards), allowing for comparison between facilities and prompt action at different levels of the health system. METHODS: We adapted the existing facility improvement tool (WASH-FIT) to create a simple numeric scoring approach. This is to illustrate the variation across hospitals and to facilitate monitoring of progress over time and to group indicators that can be used to identify this variation. Working with stakeholders, we identified those responsible for action to improve WASH at different levels of the health system and used piloting, analysis of interview data to establish the feasibility and potential value of the WASH Facility Survey Tool (WASH-FAST) to demonstrate such variability. RESULTS: We present an aggregate percentage score based on 65 indicators at the facility level to summarise hospitals' overall WASH status and how this varies. Thirty-four of the 65 indicators spanning four WASH domains can be assessed at ward level enabling within hospital variations to be highlighted. Three levels of responsibility for WASH service monitoring and improvement were identified with stakeholders: the county/regional level, senior hospital management and hospital infection prevention and control committees. CONCLUSION: We propose WASH-FAST can be used as a survey tool to assess, measure and monitor the progress of WASH in hospitals in resource-limited settings, providing useful data for decision making and tracking improvements over time.
Assuntos
Desinfecção das Mãos/métodos , Desinfecção das Mãos/normas , Higiene das Mãos/normas , Saneamento/normas , Inquéritos e Questionários/normas , Purificação da Água/normas , Organização Mundial da Saúde , Infecção Hospitalar/prevenção & controle , Estudos de Viabilidade , Saúde Global , Implementação de Plano de Saúde/normas , Hospitais , Humanos , Guias de Prática Clínica como Assunto/normas , Melhoria de Qualidade , Saneamento/métodos , Fatores de Tempo , Purificação da Água/métodos , Abastecimento de Água/normasRESUMO
The most common source of pollution is wastewater that comes from the industrial, agricultural, and household sectors. The aim of this work is to evaluate the impact of a new innovative wastewater treatment technology on the water quality of the Leite River, Lithuania. The Leite River basin receives wastewater from the Leitgiriai agglomeration; it is then released into a channel, which is 73 m away from the river. During the implementation of the BSR Interreg project "Water emissions and their reduction in village communities in the Baltic Sea Region as pilots (VillageWater)," the ineffective Leitgiriai wastewater treatment plant (WWTP) was reconstructed in September and October of 2017. Water samples from Leite River were collected in 2010-2018 in three locations: near the Kulynai, Leitgiriai, and Sausgalviai villages in Lithuania. The results show that the wastewater treatment efficiency is statistically higher than that before the reconstruction of the WWTP. The treated wastewater (before and after reconstruction) is released from the Leitgiriai WWTP into the surface water (channel), which flows into the Leite River. The highest concentrations (according to all examined indicators) have been observed in the channel and in the Leite River 500 m after the release point before the reconstruction. All differences are statistically significant (p < 0.05). According to the 2018 values, the water quality of the Leite River did comply with the good ecological status/potential class indicators near the Leitgiriai village. After the Leitgiriai WWTP reconstruction, the wastewater treatment efficiency increased two times on average. Therefore, the Leite River water quality near Leitgiriai improved.
Assuntos
Monitoramento Ambiental/métodos , Rios/química , Rios/microbiologia , Poluentes Químicos da Água/análise , Purificação da Água/normas , Qualidade da Água , Análise da Demanda Biológica de Oxigênio , Lituânia , Águas Residuárias/química , Águas Residuárias/microbiologiaRESUMO
A study was conducted to characterize the raw wastewater entering a modern cost effective municipal WWTP in Poland using two approaches; 1) a combination of modeling and carbonaceous oxygen demand (COD) fractionation using respirometric test coupled with model estimation (RT-ME) and 2) flocculation/filtration COD fractionation method combined with BOD measurements (FF-BOD). It was observed that the particulate fractions of COD obtained using FF-BOD method was higher than those estimated by RT-ME approach. Contrary to the above, the values of inert soluble fraction evaluated by FF-BOD method was significantly lower than RT-ME approach (2.4% and 3.9% respectively). Furthermore, the values for low colloidal and particulate fractions as well as soluble inert fractions were different than expected from a typical municipal wastewater. These observations suggest that even at low load (10% of the total wastewater treatment inflow), the industrial wastewater composition can significantly affect the characteristics of municipal wastewater which could also affect the performance and accuracy of respirometric tests. Therefore, in such cases, comparison of the respirometric tests with flocculation/filtration COD/BOD measurements are recommended. Oxygen uptake rate profile with settled wastewater and/or after coagulation-flocculation, however, could still be recommended as a "rapid" control method for monitoring/optimising modern cost-effective wastewater treatment plants.
Assuntos
Análise da Demanda Biológica de Oxigênio , Esgotos/química , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Análise da Demanda Biológica de Oxigênio/métodos , Análise da Demanda Biológica de Oxigênio/normas , Calibragem , Compostos Inorgânicos de Carbono/química , Fracionamento Químico/métodos , Cidades , Análise Custo-Benefício , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , Filtração , Floculação , Humanos , Oxigênio/química , Polônia , Purificação da Água/economia , Purificação da Água/métodos , Purificação da Água/normasRESUMO
Globally the nephrology community is witnessing an increased use of high-flux membranes and ultrapure water in haemodialysis (HD) units, and in low-and middle-income countries, data are lacking regarding HD water quality. In Lebanon the Ministry of Public Health released a decree calling for a progressive change in the HD water treatment system in order to implement ultrapure water in all dialysis facilities. This article reports on the problems previously encountered regarding water quality in Lebanon. It exposes the recent changes in standards as recommended by the government, especially the mandatory three sessions per week and ultrapure water. In addition, it analyses the cost-effectiveness of ultrapure water implementation in a low/middle-income country and demonstrates that the cost is lower than in high-income countries. Finally, this article summarizes the obstacles met and suggests a practical approach to maintain this high level of water treatment quality.
Assuntos
Qualidade da Assistência à Saúde , Diálise Renal/normas , Purificação da Água , Análise Custo-Benefício , Política de Saúde , Humanos , Líbano , Melhoria de Qualidade/normas , Diálise Renal/economia , Microbiologia da Água , Purificação da Água/economia , Purificação da Água/normasRESUMO
BACKGROUND: Diarrheal disease attributable to water and sanitation can be prevented using point-of-use water treatment. In Ethiopia, a small number of households treat water at point-of-use with appropriate methods. However, evidence on factors associated with household use of these treatment methods is scarce. Therefore, this study is intended to explore the household use of appropriate point-of-use water treatment and associated factors in Ethiopia. METHODS: The data of 2005, 2011, and 2016 Ethiopian demographic and health surveys were used for analysis. Households reportedly treating water with bleach, boiling, filtration, and solar disinfection in each survey are considered as treating with appropriate treatment methods. Household water treatment with these treatment methods and factors associated was assessed using bivariate and multivariable regression. In addition, a region level difference in the treatment use was assessed by using multilevel modeling. RESULTS: The number of households that reported treating water with appropriate water treatment methods was 3.0%, 8.2%, and 6.5% respectively in 2005, 2011, and 2016. Household heads with higher education had 5.99 (95% CI = 3.48, 10.33), 3.61 (95% CI = 2.56, 5.07), and 3.43 (95% CI = 2.19, 6.37) times higher odds of using the treatment methods respectively in 2005, 2011, and 2016 compared to household heads who had no education. There was a significantly high number of households that used appropriate water treatment methods in 2011 (AOR = 2.78, 95% CI = 2.16, 3.57) and 2016 (AOR = 2.18, 95% CI = 1.64, 3.89) compared to 2005 data. In pooled data analysis, the reported use of the treatment methods is associated with household head education, residency, drinking water sources, and owning radio and television. From a multilevel modeling, within-region variation is higher than between-region variations in the use of treatment methods in each survey. CONCLUSIONS: Below 10% of households reportedly treating water at point-of-use in each survey attributable to different factors. Designing intervention strategies for wide-scale use of treatment methods at the country level is fundamental.
Assuntos
Purificação da Água/métodos , Purificação da Água/estatística & dados numéricos , Adolescente , Adulto , Etiópia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores Socioeconômicos , Inquéritos e Questionários , Purificação da Água/normas , Abastecimento de Água/estatística & dados numéricos , Adulto JovemRESUMO
AIMS: The World Health Organization (WHO) has recommended Water Safety Plans (WSPs) since 2004 as a means to reduce drinking water contamination and risks to human health. These risk management programs have shown promise across several potential areas of evaluation, such as economic benefits and regulatory compliance. Since WSPs are largely carried out by people who interact with water treatment equipment and processes, operational performance indicators may be key to understanding the mechanisms behind desirable WSP impacts such as water quality and public health improvement. METHOD: This study reports performance measures collected at a WSP implementation location in southwestern France over several years. RESULTS: Quantitative assessment of performance measures supported qualitative reports from utility managers. Results indicate significantly reduced duration of low-chlorine events at one production facility and a significant decrease in customer complaints related to water quality, manifesting reported improvements in operational performance and the customer service culture. CONCLUSION: The findings demonstrate some success stories and potential areas of future performance tracking. Cyclical iteration of the WSP can help to achieve continuous quality improvement. Successfully applied evaluation criteria such as the number of water quality complaints or alarm resolution time might be useful across other locations.
Assuntos
Água Potável/normas , Monitoramento Ambiental/métodos , Gestão de Riscos/organização & administração , Qualidade da Água/normas , Abastecimento de Água/normas , Comportamento do Consumidor , França , Fidelidade a Diretrizes , Guias como Assunto , Humanos , Conhecimento , Medição de Risco , Gestão de Riscos/normas , Fatores de Tempo , Purificação da Água/métodos , Purificação da Água/normasRESUMO
The purpose of this work was to assess the risk to the environment arising from the electroplating sludge from both chemical and toxicological point of view. Both approaches were used for the assessment of the treatment efficiency which consisted of CaO based solidification followed by thermal treatment at 400°C. The elemental composition was determined in the bulk samples and the leachates of untreated sludge. The toxicity of the leachate was determined using two human colorectal adenocarcinoma cell lines (Caco-2 and SW 480) and Hordeum vulgare L. based plant bioassay. The same toxicity tests were employed to the leachate of the treated sludge. Untreated sludge showed extremely high cytotoxic effect to both human and plant bio-system in dose-dependent manner. The percentages higher than 0.5% and 0.05% of the leachate caused significant cytotoxic effect on Caco-2 and SW 480 cells, respectively. The percentages of the leachate higher than 0.05% also showed significant toxic effect to H. vulgare L. bio-system with complete arrest of seed germination following the treatment with 100% to 5% of the leachate. The leachate of the treated sludge showed no toxicity to any of the test systems confirming the efficiency and justification of the employed procedures for the detoxification of electroplating sludge.
Assuntos
Bioensaio/métodos , Galvanoplastia , Resíduos Industriais/análise , Plantas , Esgotos/análise , Testes de Toxicidade/métodos , Células CACO-2 , Monitoramento Ambiental/métodos , Germinação/efeitos dos fármacos , Hordeum , Humanos , Resíduos Industriais/efeitos adversos , Esgotos/efeitos adversos , Esgotos/química , Extração em Fase Sólida/métodos , Células Tumorais Cultivadas , Purificação da Água/métodos , Purificação da Água/normasRESUMO
BACKGROUND: Cholera prevention and control interventions targeted to neighbors of cholera cases (case-area targeted interventions [CATIs]), including improved water, sanitation, and hygiene, oral cholera vaccine (OCV), and prophylactic antibiotics, may be able to efficiently avert cholera cases and deaths while saving scarce resources during epidemics. Efforts to quickly target interventions to neighbors of cases have been made in recent outbreaks, but little empirical evidence related to the effectiveness, efficiency, or ideal design of this approach exists. Here, we aim to provide practical guidance on how CATIs might be used by exploring key determinants of intervention impact, including the mix of interventions, "ring" size, and timing, in simulated cholera epidemics fit to data from an urban cholera epidemic in Africa. METHODS AND FINDINGS: We developed a micro-simulation model and calibrated it to both the epidemic curve and the small-scale spatiotemporal clustering pattern of case households from a large 2011 cholera outbreak in N'Djamena, Chad (4,352 reported cases over 232 days), and explored the potential impact of CATIs in simulated epidemics. CATIs were implemented with realistic logistical delays after cases presented for care using different combinations of prophylactic antibiotics, OCV, and/or point-of-use water treatment (POUWT) starting at different points during the epidemics and targeting rings of various radii around incident case households. Our findings suggest that CATIs shorten the duration of epidemics and are more resource-efficient than mass campaigns. OCV was predicted to be the most effective single intervention, followed by POUWT and antibiotics. CATIs with OCV started early in an epidemic focusing on a 100-m radius around case households were estimated to shorten epidemics by 68% (IQR 62% to 72%), with an 81% (IQR 69% to 87%) reduction in cases compared to uncontrolled epidemics. These same targeted interventions with OCV led to a 44-fold (IQR 27 to 78) reduction in the number of people needed to target to avert a single case of cholera, compared to mass campaigns in high-cholera-risk neighborhoods. The optimal radius to target around incident case households differed by intervention type, with antibiotics having an optimal radius of 30 m to 45 m compared to 70 m to 100 m for OCV and POUWT. Adding POUWT or antibiotics to OCV provided only marginal impact and efficiency improvements. Starting CATIs early in an epidemic with OCV and POUWT targeting those within 100 m of an incident case household reduced epidemic durations by 70% (IQR 65% to 75%) and the number of cases by 82% (IQR 71% to 88%) compared to uncontrolled epidemics. CATIs used late in epidemics, even after the peak, were estimated to avert relatively few cases but substantially reduced the number of epidemic days (e.g., by 28% [IQR 15% to 45%] for OCV in a 100-m radius). While this study is based on a rigorous, data-driven approach, the relatively high uncertainty about the ways in which POUWT and antibiotic interventions reduce cholera risk, as well as the heterogeneity in outbreak dynamics from place to place, limits the precision and generalizability of our quantitative estimates. CONCLUSIONS: In this study, we found that CATIs using OCV, antibiotics, and water treatment interventions at an appropriate radius around cases could be an effective and efficient way to fight cholera epidemics. They can provide a complementary and efficient approach to mass intervention campaigns and may prove particularly useful during the initial phase of an outbreak, when there are few cases and few available resources, or in order to shorten the often protracted tails of cholera epidemics.
Assuntos
Vacinas contra Cólera/uso terapêutico , Cólera/epidemiologia , Cólera/terapia , Surtos de Doenças , Necessidades e Demandas de Serviços de Saúde , Modelos Teóricos , Administração de Caso/normas , Administração de Caso/estatística & dados numéricos , Cólera/prevenção & controle , Simulação por Computador , Geografia , Implementação de Plano de Saúde/normas , Necessidades e Demandas de Serviços de Saúde/normas , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Humanos , Purificação da Água/normasRESUMO
The reliability and accuracy of in-situ ion selective electrode and ultraviolet (NOx) probes have been investigated at four different treatment plants with different operational conditions. This study shows that the mentioned probes tend to compromise their accuracy and trending stability at lower NOx of <1.0 mg N/L, which if used as a measuring variable for PI feedback controller for denitrification (biological reduction of nitrate to nitrogen gas), would cause overfeeding the external carbon source. In-situ Clark-type N2O sensors, recently introduced for industrial scale use (Unisense Environment) could potentially open a new horizon in the automation of biological processes and particularly denitrification. To demonstrate the applicability of such probes for automation, two in-situ N2O probes were used in two treatment plants in parallel with NOx-N probes. The effects of operational conditions such as COD/N ratios and the correlation between NOx and N2O were investigated at those plants. N2O production at non-detect dissolved oxygen concentrations and pH of 7-7.2 were found to be a function of influent nitrogen load or the ratio of COD/NINFLUENT. Finally, using an N2O probe as a proxy sensor for nitrates is proposed as a measured variable in the PI feedback in the automation of the denitrification process with a NOx set point of <1.2 mg N/L).
Assuntos
Carbono/análise , Monitoramento Ambiental/métodos , Gases de Efeito Estufa/análise , Nitrogênio/análise , Óxido Nitroso/análise , Purificação da Água/normas , Reatores Biológicos , Desnitrificação , Monitoramento Ambiental/economia , Reprodutibilidade dos Testes , Purificação da Água/economiaRESUMO
Understanding pathogen risks is a critically important consideration in the design of water treatment, particularly for potable reuse projects. As an extension to our published microbial risk assessment methodology to estimate infection risks associated with Direct Potable Reuse (DPR) treatment train unit process combinations, herein, we (1) provide an updated compilation of pathogen density data in raw wastewater and dose-response models; (2) conduct a series of sensitivity analyses to consider potential risk implications using updated data; (3) evaluate the risks associated with log credit allocations in the United States; and (4) identify reference pathogen reductions needed to consistently meet currently applied benchmark risk levels. Sensitivity analyses illustrated changes in cumulative annual risks estimates, the significance of which depends on the pathogen group driving the risk for a given treatment train. For example, updates to norovirus (NoV) raw wastewater values and use of a NoV dose-response approach, capturing the full range of uncertainty, increased risks associated with one of the treatment trains evaluated, but not the other. Additionally, compared to traditional log-credit allocation approaches, our results indicate that the risk methodology provides more nuanced information about how consistently public health benchmarks are achieved. Our results indicate that viruses need to be reduced by 14 logs or more to consistently achieve currently applied benchmark levels of protection associated with DPR. The refined methodology, updated model inputs, and log credit allocation comparisons will be useful to regulators considering DPR projects and design engineers as they consider which unit treatment processes should be employed for particular projects.
Assuntos
Medição de Risco/métodos , Esgotos/microbiologia , Purificação da Água/normas , Benchmarking , Humanos , Norovirus , Incerteza , Vírus , Águas ResiduáriasRESUMO
With an exponential increase in urbanization and industrialization, water pollution is an inevitable consequence of relatively lagging wastewater treatment facilities. The conventional activated sludge process for wastewater treatment primarily emphasizes the removal of harmful substances to maintain increasingly stringent effluent discharged standards, which is considered an energy-intensive technique. Therefore, innovative and sustainable wastewater treatment should pay more attention to energy and resource recovery in dealing with fossil fuel depletion, global-scale energy security, and climate change. A bibliometric analysis was applied to trace wastewater-energy nexus-related research during the period 1991 to 2015, with respect to the Science Citation Index EXPANDED (SCI-EXPANDED) database. Journal of Hazardous Materials, ranking 1st in h-index (79), was the most productive journal (431, 4.5%) during the same time, followed by International Journal of Hydrogen Energy (422, 4.4%) and Water Research (393, 4.1%) journal, the latter owning a topmost journal impact factor. Though, China (2154, 22.5%) was the most productive country, while the USA with highest h-index (88) was the favorest collaborative country. The Chinese Academy of Sciences, China (241, 2.5%) produced the maximum publications. A novel method called "word cluster analysis" showed that the emerging sustainable processes and novel renewable energy application are applied in response to the desire for a net wastewater-energy nexus system. Based on different wastewater types, the emerging energy and sources recovery treatment processes of Anammox, anaerobic digestion, and microbial fuel cells gained extensive innovation. Evaluation indicators including sustainability, life cycle assessment, and environmental impact were appropriately used to dissert feasibility of the novel treatment methods in regard of renewable energy utilization, energy savings, and energy recovery. The transformation of the new concept of "broaden income source, economize on expenditures and exploit inner potential" should be generalized in order to achieve an environmentally sustainable development of wastewater-energy nexus system.
Assuntos
Bibliometria , Conservação de Recursos Energéticos/métodos , Projetos de Pesquisa , Purificação da Água/métodos , Benchmarking , China , Conservação de Recursos Energéticos/economia , Conservação dos Recursos Naturais , Fator de Impacto de Revistas , Esgotos/química , Águas Residuárias/química , Purificação da Água/economia , Purificação da Água/normasRESUMO
Household water treatment (HWT) can improve drinking water quality and prevent disease if used correctly and consistently by populations at risk. Current international monitoring estimates by the Joint Monitoring Programme for water and sanitation suggest that at least 1.1 billion people practice HWT. These estimates, however, are based on surveys that may overstate the level of consistent use and do not address microbial effectiveness. We sought to assess how HWT is practiced among households identified as HWT users according to these monitoring standards. After a baseline survey (urban: 189 households, rural: 210 households) to identify HWT users, 83 urban and 90 rural households were followed up for 6 weeks. Consistency of reported HWT practices was high in both urban (100%) and rural (93.3%) settings, as was availability of treated water (based on self-report) in all three sampling points (urban: 98.8%, rural: 76.0%). Nevertheless, only 13.7% of urban and 25.8% of rural households identified at baseline as users of adequate HWT had water free of thermotolerant coliforms at all three water sampling points. Our findings raise questions about the value of the data gathered through the international monitoring of HWT as predictors of water quality in the home, as well as questioning the ability of HWT, as actually practiced by vulnerable populations, to reduce exposure to waterborne diseases.
Assuntos
Água Potável , Características da Família , Purificação da Água/normas , Qualidade da Água , Utensílios Domésticos , Humanos , Índia , População Rural , Fatores Socioeconômicos , População Urbana , Microbiologia da Água , Abastecimento de ÁguaRESUMO
The development of entrepreneurships in the 21st century cannot occur without taking care of the natural environment. The article presents issues related to eco-innovation. Despite the opportunities offered by eco-innovations, implementation of such initiatives remains to lead to various difficulties. They vary across countries and sectors. The insufficient number of enterprises in Poland and other European countries implement adequate level of eco-innovations. The main aim of this paper is to indicate the causes of this status and activities aimed to develop eco-innovativeness. The benefits and risks connected with implementation of innovative products and technologies were also discussed. Furthermore, the advantages of and barriers to their implementation into companies were analysed. The entrepreneurs from the least eco-innovative countries emphasize serious barriers, including uncertain demand from the market, uncertain return on investment or too long a payback period for eco-innovation, lack of funds within the enterprise, insufficient access to existing subsidies and fiscal incentive. They are especially afraid of the financial risks, which raises uncertainty and leads to refraining from innovative initiatives. The possibilities were indicated for the entrepreneurs who face problems with the implementation of innovative solutions. Particular attention was paid to the European Union activities for the development of eco-innovations. Numerous programs supporting their implementation were indicated. The article also presents examples of eco-innovation in water and sewage enterprises. It was emphasized that planning of eco-innovative solutions should be based on comprehensive information about actual benefits and possibility of threats to the environment which can be caused by implementation of eco-innovations. The study presents the example of threats resulting from different methods of sewage sludge management.
Assuntos
Conservação dos Recursos Naturais/métodos , Invenções , Conservação dos Recursos Naturais/economia , Europa (Continente) , União Europeia , Invenções/economia , Esgotos/análise , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/normas , Purificação da Água/economia , Purificação da Água/normas , Abastecimento de Água/economia , Abastecimento de Água/normasRESUMO
The Study Group on Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine and Public Health (GISIO-SItI) and the Local Health Authority of Foggia, Apulia, Italy, after the National Convention "Safe water in healthcare facilities" held in Vieste-Pugnochiuso on 27-28 May 2016, present the "Vieste Charter", drawn up in collaboration with experts from the National Institute of Health and the Ministry of Health. This paper considers the risk factors that may affect the water safety in healthcare facilities and reports the current regulatory frameworks governing the management of installations and the quality of the water. The Authors promote a careful analysis of the risks that characterize the health facilities, for the control of which specific actions are recommended in various areas, including water safety plans; approval of treatments; healthcare facilities responsibility, installation and maintenance of facilities; multidisciplinary approach; education and research; regional and national coordination; communication.
Assuntos
Instalações de Saúde/normas , Segurança/normas , Microbiologia da Água/normas , Abastecimento de Água/normas , Instalações de Saúde/legislação & jurisprudência , Promoção da Saúde , Humanos , Itália , Saúde Pública/legislação & jurisprudência , Saúde Pública/normas , Fatores de Risco , Segurança/legislação & jurisprudência , Purificação da Água/legislação & jurisprudência , Purificação da Água/normas , Abastecimento de Água/legislação & jurisprudênciaRESUMO
Microbial communities of activated sludge (AS) play a key role in the performance of wastewater treatment processes. However, seasonal variability of microbial population in varying AS-based processes has been poorly correlated with operation of full-scale wastewater treatment systems (WWTSs). In this paper, significant seasonal variability of AS microbial communities in eight WWTSs located in the city of Guangzhou were revealed in terms of 16S rRNA-based Miseq sequencing. Furthermore, variation redundancy analysis (RDA) demonstrated that the microbial community compositions closely correlated with WWTS operation parameters such as temperature, BOD, NH4+-N and TN. Consequently, support vector regression models which reasonably predicted effluent BOD, SS and TN in WWTSs were established based on microbial community compositions. This work provided an alternative tool for rapid assessment on performance of full-scale wastewater treatment plants.