Several studies have been conducted on household water use and microbial water quality globally. However, studies that considered seasonal variability of household water use and microbial water ...quality were limited. Therefore, this study investigated the seasonal variability of household water use, microbiological water quality, and challenges to the provision of adequate water in the peri-urban and informal settlements of Hosanna town, Southern Ethiopia. A longitudinal study was conducted on 288 households. The data was gathered using a pretested structured questionnaire, laboratory-analysis, interviews, storage-container inventories, focus group discussions, key-informant interviews, and an observational checklist. The data was analyzed using stepwise-multiple linear regression, bivariate and multivariable logistic regression, thematic-analysis, t-tests, and non-parametric-tests. Households were visited for 7 consecutive days during the dry and rainy seasons to account for changes in daily and seasonal variation of water use. 440 stored water and 12 source samples were analyzed for
presence during dry and rainy seasons. The prevalence of stored water contamination with
was 43.2% and 34.5% during the dry and rainy seasons, respectively. The per capita water consumption was 19.4 and 20.3 l during the dry and rainy seasons, respectively. Piped water on-premises, small family size, volume, and number of water storage containers were significant predictors of per capita water consumption in both seasons. Piped water off-premises, storing water for more than 3 days, uncovered, and wide-mouthed water storage containers were significantly associated with the presence of
in water in both seasons. Seasonal variability of household water use and microbiological water quality was statistically significant, which is a significant public health concern and needs intervention to enhance water quantity and quality to mitigate the risk of waterborne diseases. Findings also suggest seasonal monitoring of the safety of drinking water to ensure that the water is safe and healthy.
In order to simulate the long-term (months–years) median Escherichia coli distributions and variations in the tidal Scheldt River and Estuary, a dedicated module was developed for the ...Second-generation Louvain-la-Neuve Ice-ocean Model (SLIM, www.climate.be/slim). The resulting model (SLIM-EC2) presents two specific and new features compared to the older SLIM-EC model version. The first is that the E. coli concentrations in the river are split in three fractions: the free E. coli in the water column, the ones attached to suspended solids and those present in the bottom sediments, each with their own transport, decay and settling–resuspension dynamics. The bacteria attached to particles can settle and survive on the bottom, where they can be brought back in the water column during resuspension events. The second new feature of the model is that it is coupled to the catchment model SENEQUE-EC, which thus provides upstream boundary conditions to SLIM-EC2. The result is an integrated and multi-scale model of the whole Scheldt drainage network from its source down to the Belgian/Dutch coastal zone. This new model reproduces the long-term median E. coli concentration along the Scheldt River and Estuary. An extensive sensitivity study is performed demonstrating the relative robustness of the model with respect to the chosen parameterisations. In addition to reproducing the observed E. coli concentrations in 2007–2008 at various stations, two extreme wastewater management scenarios were considered. Overall, there is no doubt that the Scheldt Estuary acts as a cleaning filter of faecal contamination originating from large Belgian cities. As a result, at the mouth of the Scheldt Estuary E. coli concentration is negligible in all investigated conditions.
•E. coli concentrations are modelled in the whole Scheldt catchment.•Catchment model is coupled to hydrodynamic model (tidal river and estuary).•Results compare well to field data and model sensitivity is assessed.•The impact of 2 wastewater management scenarios was traced down to the North Sea.•The estuary acts as a cleaning filter removing most E. coli before they reach the sea.
In developing countries such as South Africa, diarrhoeal diseases are reported to be linked to inadequate drinking water quality, sanitation, and hygiene behaviours. The consumption of ...microbiologically contaminated drinking water has been reported to cause diarrhoea, mortality, and morbidity in children under the age of five years. This study evaluated the microbiological pathogens detected in municipal drinking water and diarrhoea trends for children under 5 years of age in South Africa between 2008 and 2018. A trends analysis study was conducted using secondary data on diarrhoea for children under the age of five years and microbial drinking water quality compliance. A negative correlation was found between the occurrence of microbial pathogens in water, morbidity, and mortality rates of children under the age of 5 years in South Africa. As compliance status improved, the mortality rate among children under 5 years old decreased by 31% over the study period. A conclusion can thus be drawn that the microbiological pathogens detected in drinking water at levels complying with SANS 241:2015 Edition 2 standards and diarrhoea incidences were not the primary cause of the mortality of children under 5 years old in South Africa between 2008 and 2018.
Failure on the water treatment poses hemodialysis patients at risk of injury and death. Identifying if the patients are exposed to water quality related microbiological risks is an important ...objective to reduce the mortality for chronic renal patients and is the main issue of this study. We evaluated the microbiological water quality used by 205 dialysis services in São Paulo State, Brazil between 2010 to 2016. The study included heterotrophic bacteria count, total coliforms research, and bacterial endotoxin determination in 1366 dialysis water samples. The number of unsatisfactory clinics for at least one microbiological parameter decreased 16.0% between 2010 to 2015 but increased 57.2% in 2016. In 2010, the most frequent unsatisfactory parameter was related to heterotrophic bacteria count (54.8%) followed by endotoxin determination (45.2%). However, in 2013 an opposite situation was observed: endotoxin determination as the parameter of the higher incidence of nonconformities. Total coliform was verified at a lower frequency. We highlighted the importance of regular monitoring of dialysis water quality to prevent infections caused by dialytic procedures and to ensure that the water is a safe component of the treatment.
The rationale for this study was to assess the physicochemical and bacteriological qualities of the Vea irrigation water and resultant effects on the quality of fresh vegetables produced in the area ...and associated implications for consumers' health. A total of 45 water samples were collected from the reservoir and canals. Also, 16 vegetable samples comprising four samples each of tomatoes, carrots, spring onions, and cabbages were collected from four farms with installed irrigation systems fed by the Vea Dam. The irrigation water samples were analyzed for total coliform (TC) and fecal coliform (FC), Escherichia coli, pH, and turbidity, while the samples of vegetables were analyzed for TC and FC, and E. coli. The results showed that except for pH, the bacterial loads and turbidity of the sampled vegetables and irrigation water were above the standards of the WHO and the International Commission on Microbiological Specifications for Food. Comparatively, the samples of cabbage recorded the highest levels of microbial contamination. The study suggests that the water should be treated before being used for irrigation; consumers should ensure that vegetables are properly washed and cooked/treated before consumption; and periodic monitoring and assessment should be done to ensure that the adverse effects of these activities are forestalled.
It is well documented that faecal contamination of drinking water has caused numerous disease outbreaks. Because the risks of disease outbreaks correlate with the incidence of faecal contamination, ...faecal bacteria are used as indicators of faecal contamination and hence, the possible presence of disease-causing organisms. However, different microbiological faecal indicators are used in different countries and jurisdictions. Therefore, it is important to understand the potentials and limitations of these indicator organisms before realistically implementing guidelines and regulations to safeguard our water resources. This review considers the history of indicator organisms, the evolution of the analytical methodologies (biochemical and molecular) and addresses the advantages and limitations of current faecal indicator microorganisms.
To meet the growing demand for water in Bukavu town in Democratic Republic of The Congo, REGIDESO has installed a new water treatment plant in Nyalukemba district in the middle of the Bukavu town to ...treat water taken directly from Lake Kivu. This water is served to 2,133 households (or 17,064 inhabitants) subscribing to REGIDESO living in the Nguba and Muhumba localities. The purpose of this study is to analyze the physicochemical and microbiological quality of this water. The results of water samples taken at different sites in the circuit of collection, treatment, and distribution of this water reveal that the water used for treatment as well as the treated water is unfit for human consumption. The variations of physicochemical parameters and microbiological groups observed at different points in the distribution circuit show that REGIDESO is providing unsafe water to its subscribers. At the end of this article, we make recommendations to change this situation and suggest to the population consuming this water to boil it before any consumption to avoid water related health risks.
为满足刚果民主共和国布卡武市不断增加的水需求, 供水管理局 (REGIDESO)在布卡武市中部Nyalukemba区域建立了一个新的水处理厂, 用于处理直接从基伍湖获得的水源。处理后的水提供给2133户(共计17,064名居民)订购REGIDESO的家庭, 他们居住在Nguba 和Muhumba。本文目的旨在分析此水的物理‐化学质量以及微生物质量。从收集、处理和分配过程中的不同地点获取的水样本分析结果显示, 待处理水以及处理后的水均不适合饮用。分配过程中不同地点观测到的物理‐化学参数及微生物群差异显示, REGIDESO正为其客户提供不安全水。我们在本文结论处提供一系列改变该现状的建议, 并建议饮用此水的居民在饮用前进行煮沸, 以避免相关卫生风险。.
Para satisfacer la creciente demanda de agua en la ciudad de Bukavu en la República Democrática del Congo, REGIDESO ha instalado una nueva planta de tratamiento de agua en el distrito de Nyalukemba en el centro de la ciudad de Bukavu para tratar el agua extraída directamente del lago Kivu. Esta agua se sirve a 2,133 hogares (o 17,064 habitantes) suscritos a REGIDESO que viven en las localidades de Nguba y Muhumba. El propósito de este estudio es analizar la calidad físico‐química y microbiológica de esta agua. Los resultados de las muestras de agua tomadas en diferentes puntos del circuito de captación, tratamiento y distribución de esta agua, revelan que tanto el agua utilizada para el tratamiento como el agua tratada no son aptas para el consumo humano. Las variaciones de parámetros físico‐químicos y grupos microbiológicos observadas en diferentes puntos del circuito de distribución muestran que REGIDESO brinda agua no potable a sus abonados. Al final de este artículo, hacemos recomendaciones para cambiar esta situación y sugerimos a la población que consume esta agua que la hierva antes de cualquier consumo para evitar riesgos para la salud relacionados con el agua.
Recent observations in the tidal Scheldt River and Estuary revealed a poor microbiological water quality and substantial variability of this quality which can hardly be assigned to a single factor. ...To assess the importance of tides, river discharge, point sources, upstream concentrations, mortality and settling a new model (SLIM-EC) was built. This model was first validated by comparison with the available field measurements of
Escherichia coli (
E. coli, a common fecal bacterial indicator) concentrations. The model simulations agreed well with the observations, and in particular were able to reproduce the observed long-term median concentrations and variability. Next, the model was used to perform sensitivity runs in which one process/forcing was removed at a time. These simulations revealed that the tide, upstream concentrations and the mortality process are the primary factors controlling the long-term median
E. coli concentrations and the observed variability. The tide is crucial to explain the increased concentrations upstream of important inputs, as well as a generally increased variability. Remarkably, the wastewater treatment plants discharging in the study domain do not seem to have a significant impact. This is due to a dilution effect, and to the fact that the concentrations coming from upstream (where large cities are located) are high. Overall, the settling process as it is presently described in the model does not significantly affect the simulated
E. coli concentrations.
► Development and application of new reactive tracer model (SLIM-EC) for the fate of
E. coli concentrations in the tidal Scheldt River and Estuary. ► SLIM-EC reproduces correctly the long-term median concentrations and range. ► The correct longitudinal profiles can only be found by a model considering the tides, as these have the specific effect to push polluted water upstream. ► Major source of
E. coli in the domain appears to be lying upstream the domain, so for water quality improvement the efforts should be concentrated on improving the inputs upstream of the model boundaries.
In this study, we investigated the microbiological quality of the small urban Zenne River which flows through the city of Brussels (Belgium). The abundances of faecal indicator bacteria (FIB) ...(Escherichia coli and intestinal enterococci) revealed high levels of faecal contamination of the Zenne River, especially in Brussels area and downstream from this area where FIB were in the range of what is usually observed in secondary treated wastewaters. The origin of this faecal contamination is mainly attributed to the effluents of the two wastewater treatment plants (WWTPs) located along the river in Brussels. Comparison of the present situation with the 1990s situation (before the implementation of Brussels WWTPs) showed a sharp improvement of the river microbiological quality. This improvement should however be regarded with care as it was also observed that, during rain events, combined sewer overflows (CSO) outfalls were responsible of a strong increase of faecal contamination in the river downstream from Brussels, and such CSO occur frequently in Brussels. Altogether, these results document the variations of the microbiological quality of a sewage-polluted urban river in relation with long-term changes (implementation of WWTP) and the short-term disturbances (CSO).
Flow cytometry was applied to assess the microbiological impact of treated sewage effluent discharge into a small brook carrying surface runoff water. Increases in dissolved organic carbon and ...soluble reactive phosphorous were accompanied by increases in counts of intact bacteria by up to eightfold. Effluent ingress furthermore resulted in a pronounced shift of bacterial clusters. Whereas brook water upstream of the discharge point was characterised by a bacterial cluster with low nucleic acid (LNA) content, downstream water showed a shift to bacteria with high nucleic acid (HNA) content. Changes in the LNA/HNA ratio were largely maintained along the course of the brook. Results suggest that the LNA/HNA ratio can under certain conditions serve as an indicator of anthropogenic nutrient impact. Measuring impact on this low trophic level might be more sensitive and straightforward than measuring macroindicators. More evidence will however be required to assess the usefulness of LNA/HNA measurements to assess the ecological nutrient status of natural waters and the impact of nutrient pollution.
PDF
