Adjusting for the operational environment in studies of performance measurement is very important, otherwise the analysis may lead to unrealistic scores, especially when its influence on costs is ...high, such as in the water utilities. In this paper, we study the influence of exogenous variables on the water utilities performance by applying conditional efficiency measures based on the order-m method and its probabilistic formulation. We use a sample of 66 water utilities operating between 2002 and 2008, representing about 70% of the Portuguese population. Our research suggests that inefficiency of Portuguese water utilities is substantial for some utilities: several exogenous variables might influence it considerably. For example, regulation has a positive influence on efficiency but when drinking water supply and wastewater services are provided by the same utility or when the wholesale and retail activities are provided together, the performance is lower. The effect of ownership is inconclusive and the variables residential customers, water source, peak factor, and density of customers have a mixed influence on performance which varies according to their scores.
► We found that the operational environment influences the water utilities efficiency. ► Regulation has a positive influence on performance. ► The joint provision of water and wastewater has an adverse effect on performance. ► We also found that the effect of ownership is inconclusive. ► The customers and their density, water source and peak factor have a mixed influence.
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.
The WHO Consensus Document on the epidemiology of the SARS epidemic in 2003, included a report on a concentrated outbreak in one Hong Kong housing block which was considered a 'super-spreading ...event'. The WHO report conjectured that the sanitary plumbing system was one transmission route for the virus. Empty U-traps allowed the aerosolised virus to enter households from the sewerage system. No biological evidence was presented. This research reports evidence that pathogens can be aerosolised and transported on airstreams within sanitary plumbing systems and enter buildings via empty U-traps. A sanitary plumbing system was built, representing two floors of a building, with simulated toilet flushes on the lower floor and a sterile chamber with extractor fan on the floor above. Cultures of a model organism, Pseudomonas putida at 106-109 cfu ml-1 in 0·85% NaCl were flushed into the system in volumes of 6 to 20 litres to represent single or multiple toilet flushes. Air and surface samples were cultured on agar plates and assessed qualitatively and semi-quantitatively. Flushing from a toilet into a sanitary plumbing system generated enough turbulence to aerosolise pathogens. Typical sanitary plumbing system airflows (between 20-30 ls-1) were sufficient to carry aerosolised pathogens between different floors of a building. Empty U-traps allowed aerosolised pathogens to enter the chamber, encouraging cross-transmission. All parts of the system were found to be contaminated post-flush. Empty U-traps have been observed in many buildings and a risk assessment indicates the potential for high risk cross-transmission under defect conditions in buildings with high pathogen loading such as hospitals. Under defective conditions (which are not uncommon) aerosolised pathogens can be carried on the airflows within sanitary plumbing systems. Our findings show that greater consideration should be given to this mode of pathogen transmission.
A Changing Framework for Urban Water Systems Hering, Janet G; Waite, T. David; Luthy, Richard G ...
Environmental science & technology,
10/2013, Volume:
47, Issue:
19
Journal Article
Peer reviewed
Open access
Urban water infrastructure and the institutions responsible for its management have gradually evolved over the past two centuries. Today, they are under increasing stress as water scarcity and a ...growing recognition of the importance of factors other than the cost of service provision are forcing a reexamination of long-held ideas. Research and development that supports new technological approaches and more effective management strategies are needed to ensure that the emerging framework for urban water systems will meet future societal needs.
The world is facing a pandemic of unseen proportions caused by a corona virus named SARS-CoV-2 with unprecedent worldwide measures being taken to tackle its contagion. Person-to-person transmission ...is accepted but WHO only considers aerosol transmission when procedures or support treatments that produce aerosol are performed. Transmission mechanisms are not fully understood and there is evidence for an airborne route to be considered, as the virus remains viable in aerosols for at least 3 h and that mask usage was the best intervention to prevent infection.
Heating, Ventilation and Air Conditioning Systems (HVAC) are used as a primary infection disease control measure. However, if not correctly used, they may contribute to the transmission/spreading of airborne diseases as proposed in the past for SARS.
The authors believe that airborne transmission is possible and that HVAC systems when not adequately used may contribute to the transmission of the virus, as suggested by descriptions from Japan, Germany, and the Diamond Princess Cruise Ship. Previous SARS outbreaks reported at Amoy Gardens, Emergency Rooms and Hotels, also suggested an airborne transmission.
Further studies are warranted to confirm our hypotheses but the assumption of such way of transmission would cause a major shift in measures recommended to prevent infection such as the disseminated use of masks and structural changes to hospital and other facilities with HVAC systems.
The 2021 volcanic eruption at La Palma, Canary Islands, was the island's most voluminous historical eruption. Little is known about this volcano's feeding system. During the eruption, seismicity was ...distributed in two clusters at ~10-14 km and ~33-39 km depth, separated by an aseismic zone. This gap coincides with the location of weak seismic swarms in 2017-2021 and where petrological data have implied pre-eruptive magma storage. Here we use seismological methods to understand the seismic response to magma transfer, with 8,488 hypocentral relocations resolving small-scale seismogenic structures, and 156 moment tensors identifying stress heterogeneities and principal axes flips. Results suggest a long-lasting preparatory stage with the progressive destabilisation of an intermediate, mushy reservoir, and a co-eruptive stage with seismicity controlled by the drainage and interplay of two localised reservoirs. Our study provides new insights into the plumbing system that will improve the monitoring of future eruptions in the island.
La Ingeniería Sanitaria surge como una rama de la ingeniería que involucra tanto materias propias de la ingeniería tales como: matemáticas, física, química hidráulica o mecánica, como aquellas ...relacionada con la medicina y la higiene, tales como la microbiología y conservación. Tiene como función principal crear y fomentar condiciones de salubridad en las poblaciones siendo vigilante de las aguas, el aire y la tierra, evitando que la contaminación alcance a los seres humanos. En Perú, la ingeniería sanitaria se creó como un apéndice de la ingeniería civil, pero pronto tomó el lugar merecido, declarándose una carrera de ingeniería independiente. Actualmente, la Ingeniería sanitaria es la encargada de llevar agua potabilizada a la población, y tratar las aguas servidas. Por otra parte, con la llegada del SARS-CoV-2, el mundo fue sacudido, y una situación de pandemia emergió, lo que hizo que los diferentes países tomasen las acciones necesarias, tal como sucedió con el Perú. Allí, la Ingeniería Sanitaria, accionó sus funciones, buscando la potabilización del agua de consumo. En estos tiempos de pandemia, tambien determinaron el resguardo de la población, lo que fomentó la educación remota. En el caso de la Ingeniería Sanitaria, los laboratorios presenciales y convencionales fueron sustituidos por laboratorios virtuales y remotos, lo cual permitió que la educación continuase sin contratiempos.
The Olburgen sewage treatment plant has been upgraded to improve the effluent quality by implementing a separate and dedicated treatment for industrial (potato) wastewater and reject water. The ...separate industrial treatment has been realized within a beneficial public-private partnership. The separate treatment of the concentrated flows of industrial wastewater and sludge treatment effluent proved to be more cost-efficient and area and energy efficient than a combined traditional treatment process. The industrial wastewater was first treated in a UASB reactor for biogas production. The UASB reactor effluent was combined with the reject water and treated in a struvite reactor (Phospaq process) followed by a one stage granular sludge nitritation/anammox process. For the first time both reactors where demonstrated on full scale and have been operated stable over a period of 3 years. The recovered struvite has been tested as a suitable substitute for commercial fertilizers. Prolonged exposure of granular anammox biomass to nitrite levels up to 30 mg/l did not result in inhibition of the anammox bacteria in this reactor configuration. The chosen option required a 17 times smaller reactorvolume (20,000 m(3) less volume) and saves electric power by approximately 1.5 GWh per year.
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