scholarly journals The effect of A-dec ICX TM on microbiological water quality in self-contained dental units' water systems

2020 ◽  
Vol 75 (7) ◽  
pp. 367-372
Author(s):  
Shamaka P Kgabi ◽  
Sibusiso R Mthethwa
Keyword(s):  
Water Quality ◽  
Small Diameter ◽  
Water Systems ◽  
Treatment Protocols ◽  
Municipal Water Supply ◽  
Point Of Use ◽  
Dental Unit Waterlines ◽  
Microbiological Water Quality ◽  
Continuous Chemical ◽  
Dental Professionals

The contamination of dental unit waterlines (DUWLs) as a result of biofilms that adhere to the inner surfaces of the lines continues to generate concern. The biofilm serves as a reservoir that can increase the number of free-floating microorganisms in the water used for dental treatment.Recent studies found that it presents a confirmed but limited risk to immunocompetent individuals, but may pose a significant hazard for immunocompromised patients and dental professionals. DUWLs are prone to biofilm formation because of their small diameter and water stagnation. Untreated or unfiltered dental unit water is likely to contain high numbers of microorganisms and is unlikely to meet standards for water used as a cool-ant/irrigant for nonsurgical dental procedures.Common approaches to improve water quality include self-contained water systems combined with periodic or continuous chemical treatment protocols, daily draining, air purging regimens, anti-retraction valves, point of use micro-filters, as well as flushing waterlines for several minutes in the morning and after every patient. Centralized systems designed for single chair or entire practice waterlines that purify or treat incoming water to remove or inactivate microorganisms are becoming more popular.In most dental settings, treatment water comes from the municipal water supply directly into the dental unit.

scholarly journals Can Material and Energy Be Saved by Differentiating Water Quality Targets in the Water Purification Process?

2020 ◽  
Vol 12 (20) ◽  
pp. 8730
Author(s):  
Sébastien M. R. Dente ◽  
Toshiyuki Shimizu ◽  
Tao Wang ◽  
Seiji Hashimoto
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Treatment Plant ◽  
Water System ◽  
Water Systems ◽  
Quality Parameters ◽  
Water Supply Systems ◽  
Municipal Water Supply ◽  
Product Service ◽  
The Cost

The current organization of water supply systems demands drinking standards for all the households’ usage of water. Few dual water systems, i.e., systems in which the quality of the water supplied is differentiated by types of use, exist but are mainly circumscribed to developing countries. Besides, bath and showers are so far considered as a potable use of water despite only drinking and cooking activities requiring the high-quality standards of potable water. The present work demonstrates how the principles of dual water systems can be incorporated into the sustainable concept of product-service system (PSS) using a dual water system of a municipal water supply treatment plant in France as a case study. The PSS is based on the water quality, and the bathing activity of households is considered with a dedicated standard for the first time. Two systems are considered, S1 and S2, supplied with the same raw water quality and treated with drinking (S1) bathing standards (S2). The quality parameters considered are total organic carbon (TOC) and turbidity (T) and the potential savings related to costs, material, and energy consumptions are assessed using EVALEAU as a process modeling tool. The treatment lines consisted of powdered activated carbon (PAC) addition, coagulation, flocculation, settling, and rapid sand filtration. Results show that material consumption can be reduced by 41% mainly through the decrease in chemical consumption associated with the change of requirement for the TOC parameter. On the opposite, energy consumption was found dependent on the water of volume treated rather than its quality leading to only marginal savings. The cost was decreased by 37% as a result of the reduction of the chemicals consumed.

The relationship between health effects in triathletes and microbiological quality of freshwater

1995 ◽  
Vol 31 (5-6) ◽  
pp. 19-26 ◽  
Author(s):  
G. J. Medema ◽  
I. A. van Asperen ◽  
J. M. Klokman-Houweling ◽  
A. Nooitgedagt ◽  
M. J. W. van de Laar ◽  
...  
Keyword(s):  
Water Quality ◽  
Geometric Mean ◽  
Microbiological Quality ◽  
Quality Parameters ◽  
Health Complaints ◽  
E Coli ◽  
Thermotolerant Coliforms ◽  
Microbiological Water Quality ◽  
The Relationship ◽  
Faecal Streptococci

This pilot study was carried out to determine the relationship between microbiological water quality parameters and the occurrence of health complaints among triathletes. Data were collected at an Olympic distance triathlon (n=314) and a run-bike-run (n=81; controls for exposure to fresh water). At the time of the triathlon, the concentrations of Escherichia coli , thermotolerant coliforms, faecal streptococci, entero- and reoviruses, F-specific RNA phages, Salmonella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Pseudomonas aeruginosa and Staphylococcus aureus were examined over the swimming course. Information on the occurrence of health complaints during the competition and in the week thereafter was collected through a written questionnaire. The results show that triathletes and run-bike-runners are comparable with respect to factors other than water exposure (age, sex, training history, physical stress, lower intestinal health complaints during the competition) that may influence the occurrence of health complaints in the week after the competition. Triathletes and run-bike-runners reported gastro-intestinal (7.7% vs 2.5%), respiratory (5.5% vs 3.7%), skin/mucosal (2.6% vs 1.2%), general (3.5% vs 1.2%) and total symptoms (14.8% vs 7.4%) in the week after the event. The health risks for triathletes for all symptom groups are not significantly higher than for run-bike-runners. The geometric mean concentration of faecal indicator bacteria is relatively low: E. coli 170/100 ml; faecal streptococci 13/100 ml, enteroviruses were present at concentrations of 0.1/l. The group of triathletes was homogeneusly and relatively intensely exposed to water; they all swam in the same body of water at the same time and 75% reported to have swallowed freshwater. It was concluded that this study design is suitable to study the relationship between health complaints and microbiological water quality. In the summers of 1993 and 1994, a study will be carried out concerning several run-bike-runs and triathlons in freshwaters of different quality.

Sewers and the Quality of Canals and Ditches in Amsterdam

1993 ◽  
Vol 27 (5-6) ◽  
pp. 61-67 ◽  
Author(s):  
E. Jacobs ◽  
J. W. van Sluis
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Sediment Quality ◽  
Water System ◽  
Water Systems ◽  
Sewer System ◽  
Water And Sediment ◽  
Combined Sewer ◽  
Water And Sediment Quality

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.

scholarly journals Risk-based principles for defining and managing water security

2013 ◽  
Vol 371 (2002) ◽  
pp. 20120407 ◽  
Author(s):  
Jim Hall ◽  
Edoardo Borgomeo
Keyword(s):  
Water Quality ◽  
Public Policy ◽  
Risk Management ◽  
Water Security ◽  
Water Systems ◽  
Economic Systems ◽  
Water Resources Planning ◽  
Widespread Application ◽  
Trade Offs ◽  
Resources Planning

The concept of water security implies concern about potentially harmful states of coupled human and natural water systems. Those harmful states may be associated with water scarcity (for humans and/or the environment), floods or harmful water quality. The theories and practices of risk analysis and risk management have been developed and elaborated to deal with the uncertain occurrence of harmful events. Yet despite their widespread application in public policy, theories and practices of risk management have well-known limitations, particularly in the context of severe uncertainties and contested values. Here, we seek to explore the boundaries of applicability of risk-based principles as a means of formalizing discussion of water security. Not only do risk concepts have normative appeal, but they also provide an explicit means of addressing the variability that is intrinsic to hydrological, ecological and socio-economic systems. We illustrate the nature of these interconnections with a simulation study, which demonstrates how water resources planning could take more explicit account of epistemic uncertainties, tolerability of risk and the trade-offs in risk among different actors.

scholarly journals Field Spectroscopy as a Tool for Enhancing Water Quality Monitoring in the ACE Basin, SC

2017 ◽  
pp. 41-55 ◽  
Author(s):  
Caitlyn C. Mayer ◽  
Khalid A. Ali
Keyword(s):  
Water Quality ◽  
South Carolina ◽  
Chlorophyll A ◽  
Algal Species ◽  
Water Quality Monitoring ◽  
Water Systems ◽  
Quality Monitoring ◽  
Least Squares Regression ◽  
Monitoring Methods

The Ashepoo, Combahee, Edisto (ACE) Basin in South Carolina is one of the largest undeveloped estuaries in the Southeastern United States. This system is monitored and protected by several government agencies to ensure its health and preservation. However, as populations in surrounding cities rapidly expand and land is urbanized, the surrounding water systems may decline from an influx of contaminants, leading to hypoxia, fish kills, and eutrophication. Conventional in situ water quality monitoring methods are timely and costly. Satellite remote sensing methods are used globally to monitor water systems and can produce an instantaneous synopsis of color-producing agents (CPAs), including chlorophyll-a, suspended matter (TSM), and colored-dissolved organic matter by applying bio-optical models. In this study, field, laboratory, and historical land use land cover (LULC) data were collected during the summers of 2002, 2011, 2015, and 2016. The results indicated higher levels of chlorophyll, ranging from 2.94 to 12.19 μg/L, and TSM values were from 60.4 to 155.2 mg/L between field seasons, with values increasing with time. A model was developed using multivariate, partial least squares regression (PLSR) to identify wavelengths that are more sensitive to chlorophyll-a (R2 = 0.49; RMSE = 1.8 μg/L) and TSM (R2 = 0.40; RMSE = 12.9 mg/L). The imbrication of absorption and reflectance features characterizing sediments and algal species in ACE Basin waters make it difficult for remote sensors to distinguish variations among in situ concentrations. The results from this study provide a strong foundation for the future of water quality monitoring and for the protection of biodiversity in the ACE basin.

scholarly journals Detection of Microcystins in Lake Manatee and Lake Washington – Two Florida Drinking Water Systems

2021 ◽  
Author(s):  
Rajesh Melaram ◽  
Brandon Lopez-Dueñas
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Surface Water Quality ◽  
Well Being ◽  
Water Systems ◽  
Enzyme Linked Immunosorbent Assay ◽  
Water Supplies ◽  
Intrinsic Nature ◽  
Lake Washington ◽  
Drinking Water Systems

Clean, fresh, and safe drinking water is essential to human health and well-being. Occasionally, chemical pollutants taint surface water quality used for consumption. Microcystins (MCs) are toxic heptapeptides produced by freshwater cyanobacteria. These secondary metabolites can reach hazardous concentrations, impairing surface drinking water supplies. Inconsistent screening of MCs is not uncommon in Florida waters as no provisional guidance value is established to protect public health. The occurrence of MCs in Lake Manatee and Lake Washington was monitored over the potential peak algae bloom season (June-August). An indirect competitive enzyme-linked immunosorbent assay (icELISA) quantified total MCs in two drinking water systems. Varied concentrations occurred between June and July, whereas concentrations peaked in August. Overall, MC prevalence was higher in Lake Manatee than Lake Washington. Colorimetric assays measured phosphate and nitrite in environmental water samples. Phosphate and nitrite concentrations strongly correlated with total MCs (p < 0.01). The results indicate the intrinsic nature of environmental MCs in surface drinking water supplies and the need to examine hepatotoxin dynamics to preserve drinking water quality in community served areas.

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