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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of drinking water quality in Lake Mzingazi in Richards Bay.

Mathenjwa, Cleopas Mzondeni. January 2009 (has links)
Introduction Lake Mzingazi is the only suitable source of domestic water supply for the Richards Bay community. Rapid industrialisation in the city of uMhlathuze, accompanied by an influx of people, has resulted in informal settlement occurring around the lake. The uncontrolled activities of this development threaten to pollute the water source. Previous studies in1979 conducted by Council of Scientific & Industrial Research indicated that Lake Mzingazi water was still within acceptable limits in terms of the Department of Water Affairs & Forestry guidelines. The lake water quality was that of a Class I water resource, which is excellent for domestic use. Pollution of the lake can result from diffuse sources of pollution due to settlement of communities around it. Water purification costs could escalate thus forcing an increase in water tariffs. If pollution resulted in the lake being unable to be utilized, the Richards Bay community will be seriously affected, as it would necessitate the importing of water from distant regions. Either way, the expense of acquiring water would increase. All living organisms rely on adequate water for their survival. Worse still are human beings for their water should not only be adequate but should be of good quality to prevent health risks and even death. It is in view of these possibilities that the study was undertaken. Aim The aim of the study is to assess the extent of physical, chemical and biological pollution in Lake Mzingazi due to non-point sources and to recommend necessary protection measures that need to be implemented to prevent any negative health impact on surrounding communities. At present there are no restrictions and no protection of the lake from pollution except that no recreation is allowed into the lake at present. Methods Several objectives were set in order to focus on specific issues. One of the objectives was to inform the communities around the lake about the study. Sampling of the lake water was conducted monthly from June to November 2006 (using a boat). Pictures of areas around the lake were also taken for further analysis. At each sampling run, 36 samples were taken and delivered to a laboratory accredited by the South African National Accreditation Standards for analyses. Six sampling runs were completed. Secondary data for the period of 1998 to 2005 were obtained from uMhlathuze Municipality in order to establish pollution trends and for comparison purposes with the Department of Water Affairs and Forestry guidelines. Results The findings of the study revealed that the quality of the lake water is still within acceptable limits when compared with the Department of Water Affairs & Forestry guidelines; however, informal settlement threatens the future of the lake by encroaching into the lake banks. Discussion There is definitely a risk of pollution to Lake Mzingazi as long as there are no pollution prevention plans in place. Recommendations All data should be stored in a centralized information system to avoid losing valuable information. The Water Services Authority must develop and maintain a water quality-monitoring programme that will capture all changes occurring in the lake. / Thesis (MMed.)-University of KwaZulu-Natal, Durban, 2009.
2

Role of biological monitoring in water quality assessment and a case study on the Crocodile River, Eastern Transvaal

Roux, Dirk Johannes 14 May 2014 (has links)
M.Sc. (Zoology) / National water quality monitoring in South Africa has in the past mainly focused on measuring physical and chemical variables. However, it is increasingly realised that measuring physical and chemical variables on their own cannot provide an accurate account of the general "health" of an aquatic ecosystem. Biological communities, on the other hand, are accurate indicators of overall environmental conditions. Water quality management must, therefore, rely on comparative data for both chemical composition and biological effects. In fact, it appears as if biological monitoring (biomonitoring) is worldwide becoming a primary tool in assessing environmental condition and verifying compliance with effluent discharge. This study classified different biomonitoring approaches and techniques under bioassessment (referring to the field oriented biomonitoring protocols which make use of biotic indices to assess water quality); bioassays (toxicity tests which is usually laboratory-based); behavioural bioassays (including aspects such as early warning systems, and preference and avoidance studies); bacteriological studies (the monitoring of certain microbes to allow the detection of faecal contamination); measurement of bioaccumulation (referring to the methods by which the uptake and retention of chemicals in the body of an organism can be monitored); and fish pathology (fish health studies dealing with the causes, processes and effects of disease). Habitat assessment and evaluation was identified as an essential part of any biosurvey. There can be little uncertainty about the mutual dependence of habitat quality, biological health and chemical characteristics of water in the environment. Relative habitat condition, as the principal determinant of attainable biological potential, should set the context for interpreting the results of a biosurvey and can be used as a general predictor of biological condition. Chemistry can further help to explain and characterise certain impacts. The Crocodile River, Eastern Transvaal, was selected for conducting a case study. The SASS2 rapid bioassessment protocol, as well as a habitat quality index (Hal) was used during five consecutive biosurveys. From the results obtained in this study, it appears as if biomonitoring can be used to good effect in overall environmental assessment. The SASS2 index appeared to be both a robust and sensitive indicator of environmental condition. Application of the SASS2 technique on a regional or even national basis should be feasible with regard to simplicity and practicality. It is also cheaper and less labour intensive than comprehensive chemical monitoring. However, bioassessments should not replace but rather compliment chemical and physical monitoring.
3

EVALUATION OF THE CONTRIBUTION METAGENOMIC SHOTGUN SEQUENCING HAS IN ASSESSING POLLUTION SOURCE AND DEFINING PUBLIC HEALTH AND ENVIRONMENTAL RISKS

Unknown Date (has links)
State-approved membrane filtration (MF) techniques for water quality assessments were contrasted with metagenomic shotgun sequencing (MSS) protocols to evaluate their efficacy in providing precise health-risk indices for surface waters. Using MSS, the relative numerical abundance of pathogenic bacteria, virulence and antibiotic resistance genes revealed the status and potential pollution sources in samples studied. Traditional culture methods (TCM) showed possible fecal contamination, while MSS clearly distinguished between fecal and environmental bacteria contamination sources, and pinpointed actual risks from pathogens. RNA MSS to detect all viable microorganisms and qPCR of fecal biomarkers were used to assess the possible environmental risk between runoff drainage canals and a swamp area with no anthropogenic impact. Results revealed higher levels of pathogenic bacteria, viruses, and virulence and antibiotic resistance genes in the canal samples. The data underscore the potential utility of MSS in precision risk assessment for public and biodiversity health and tracking of environmental microbiome shifts by field managers and policy makers. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
4

Comparing Acid and Metal Loading Before and After Stream Capturing Subsidence Closure

Sullivan, Nora M. 22 July 2016 (has links)
No description available.
5

Dynamic fugacity modeling in environmental systems

Gokgoz Kilic, Sinem. January 2008 (has links)
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Aral, Mustafa; Committee Member: Guan, Jiabao; Committee Member: Pavlostathis, Spyros; Committee Member: Uzer, Turgay; Committee Member: Yiacoumi, Sotira.
6

Water in the coal mining industry : an assessment of water management issues facing the coal mining industry of the Witbank and Middelburg Dam catchments

Chelin, Monique Josette 29 May 2006 (has links)
Please read the abstract in the section 00front of this document / Dissertation (MSc)--University of Pretoria, 2007. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted
7

Dynamic fugacity modeling in environmental systems

Gokgoz Kilic, Sinem 26 March 2008 (has links)
Fully-dynamic, continuous fugacity-based fate and transport models have been developed to examine all natural processes and interactions in the aquatic water systems. Within a body of surface water such as a lake or a river, a dynamic interaction among different media takes place. Chemical compounds are continuously dissolving, adsorbing into solid particles, attaching to suspended particles, resuspending, reacting, diffusing, and advecting. As the inclusion of all these interactions into a model is complex, the use of fugacity concept instead of concentration, renders the modeling task relatively easy. Fugacity, which is described as the escaping tendency of a chemical from a medium, is continuous among different phases, thus easier to follow the movement of the chemical. The first model has been developed to be used as an emergency response model by decision makers, which models the fate and transport of any contaminant in a lake. Due to uncertainties involved in the analysis, Monte Carlo simulations are performed. The fate of three representative contaminants; polychlorinated biphenyls (PCBs), atrazine, and benzene in air, water, and sediment compartments are examined. The second model developed is a continuous, dynamic river fugacity-based water quality model. In order to develop a continuous model, the hydrodynamics of the river system is solved first. Water depth and velocity at each point along the river are used in the advection-dispersion equation to determine the fate and transport of a contaminant. Interactions between different phases are also incorporated into the advection-dispersion equation which is solved numerically and coupled with a mass balance equation derived for the same contaminant in the sediments. The third model is a multispecies contaminant fate and transport model which can be used for the fate of a single contaminant and its daughter products. Trichloroethylene (TCE) and its daughter products, dichloroethylene (DCE) and vinyl chloride (VC), are used as representative of multispecies contaminants. The fate and transport of TCE and its daughter products has been analyzed first in a lake environment, and then in a river environment with the addition of a biofilm compartment where all biotransformations take place.

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