932 resultados para Chemical quality


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Constructed wetlands are a common structural treatment measure employed to remove stormwater pollutants and forms an important part of the Water Sensitive Urban Design (WSUD) treatment suite. In a constructed wetland, a range of processes such as settling, filtration, adsorption, and biological uptake play a role in stormwater treatment. Occurrence and effectiveness of these processes are variable and influenced by hydraulic, chemical and biological factors. The influence of hydraulic factors on treatment processes are of particular concern. This paper presents outcomes of a comprehensive study undertaken to define the treatment performance of a constructed wetland highlighting the influence of hydraulic factors. The study included field monitoring of a well established constructed wetland for quantity and quality factors, development of a conceptual hydraulic model to simulate water movement within the wetland and multivariate analysis of quantity and quality data to investigate correlations and to define linkages between treatment performance and influential hydraulic factors. Total Suspended Solids (TSS), Total Nitrogen (TN) and Total Phosphorus (TP) concentrations formed the primary pollutant parameters investigated in the data analysis. The outcomes of the analysis revealed significant reduction in event mean concentrations of all three pollutants species. Treatment performance of the wetland was significantly different for storm events above and below the prescribed design event. For events below design event, TSS and TN load reduction was comparatively high and strongly influenced by high retention time. For events above design event, TP load reduction was comparatively high and was found to be influenced by the characteristics of TP wash-off from catchment surfaces.

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Background: The prevalence of end-stage kidney disease (ESKD) patients is increasing in Vietnam; however, the impact of ESKD and its treatment on a person’s quality of life (QOL) is not well understood. Objective: This research sought to examine the association between monthly income, comorbidity, length of time on dialysis, social support and health-related quality of life (HRQOL) among Vietnamese ESKD patients. Method: Using a descriptive design, 95 patients who were receiving haemodialysis (HD) and peritoneal dialysis (PD) from one hospital in Hanoi, were conveniently sampled. Results: ESKD patients reported having a moderate level of HRQOL. Factors associated with QOL were social support (r= .268, p<.05), comorbid health conditions (r= –.185, p<.05), and length of time on dialysis (r= .182, p<.05). However, monthly income was not significantly related to HRQOL (p>.05). Conclusion: The results seem to indicate that ESKD patients in Vietnam have a high level of support from family members, friends and significant others. There was also a negative impact of comorbid conditions on the QOL of these patients. Based on the results of this study, nurses ought to develop nursing interventions which will lead to a better QOL for patients, and further research into the QOL for ESKD patients in Vietnam is warranted.