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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.
151

Predicting the Site-Specific Bioavailability of Zinc Using the Indicator Species Procedure: A Case Study

Parkerton, Thomas F. 05 1900 (has links)
National Water Quality Criteria intended to protect aquatic life and their uses from the adverse effects of pollutants may not be appropriate due to site-specific factors that alter chemical bioavailability. The Indicator Species Procedure may be used to derive site-specific criteria in order to account for differences in site-specific bioavailability. This procedure was implemented using zinc for three chemically different site (river) waters. The purpose of this study was to quantify the bioavailability of zinc in each site water and correlate results to water quality parameters and/or zinc speciation. Results demonstrated that national criteria for zinc accurately predicted the experimentally derived site-specific values within a factor of two when adjusted for water hardness. Particulate forms of zinc were shown to be biologically unavailable under conditions tested.
152

The effects of chrome mining activities on the water quality of the Hex River in the Rustenburg area: case study on Kroondal chrome mine

Mavunda, Alter Nyiko January 2016 (has links)
Research Report Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Science in Environmental Sciences Date: May 2016 / This study assesses the water quality status of the Hex River downstream of Kroondal Mine (KMS15, sampling point located downstream of Kroondal Mine) and the effects of mining activities (Kroondal Chrome Mine) on the water quality of the Hex River in Rustenburg, which is in the North West Province of South Africa. Potential pollutants were identified, quantified and their distribution was determined over seven years (2007 to 2013) along different sampling points upstream and downstream to the mine. Water quality-monitoring data was obtained from the mine. The surface and underground water was sampled on a monthly basis and analysed by Aquatico, (a water quality service provider of Kroondal Chrome Mine) at SANAS Accredited Testing Laboratory (No T0374). Data was collected for the Hex River and its tributary; the nearby discharge from Crocodile Farm and Farm Dam; as well as mine containment dams, slimes dams, run-off from the processing plant and water dams within the mine. Descriptive statistics (mean/average, minimum and Maximum) and box plots are used to explain the water quality at all sampling points. Water quality from sampling location points was compared against the Total Water Quality Guideline Range (TWQGR) for irrigation, livestock watering, ideal domestic use, aquatic ecosystem limits and the exemption permit issued to the Kroondal Chrome Mine by the Department of Water Affairs and Forestry (DWAF) in 2007, now Department of Water and Sanitation (DWS). The water quality of the Hex River, downstream of Kroondal, was described as neutral, alkaline, saline and very hard with a high pH, and a high concentration of Electric conductivity (EC), Total Dissolve Solids (TDS), Chlorine (Cl), Sulphate (SO4), Nitrate (NO3), Ammonium (NH3), Hardness (CaCO3) and Orthophosphate (PO4). Pollution sources and pathways were identified using the study area layout and by conducting an impact pathway analysis using annual descriptive statistical (annual mean or average values) of water quality tables generated by SAS enterprise 6.1 (a software used to analysed descriptive statistics of the mine water quality data) for a period 2007 until 2013, and box pots graphs showing monthly water-quality data for pH, EC, TDS, Cl, SO4, NO3, NH3, CaCO3 and PO4 at 15 monitoring localities between Kroondal Chrome Mine, the Hex River and its tributaries (Kroondal tributary and Sandspruit) over seven years. It was concluded that the surface/groundwater of the Kroondal Chrome Mine process – such as seepage from slimes dams, plant run-off and the vent shaft underground water dam – had an influence on the water quality of Hex River with regard to the discharge of pH modifying pollutants, EC, TDS, Cl, SO4, NO3, NH3, CaCO3 and PO4. Other pollution sources were discharge from Crocodile Farm and Hex River, as well as the Sandspruit upstream sources such as mining (platinum and chrome), industries’ municipal sewage treatment works, agricultural activities and informal settlements activities. Mine pollutants or constituents were identified as a unique example of the compound impact of weathering, hydrologic and anthropogenic processes such as the increased use of explosives containing NO3 and NH3 underground. The chemical compositions of surface water in the mine sampling location were strongly influenced by rock water in tractions, dissolution and dilution, as well as anthropogenic inputs. Key insights drawn from the study is that, cumulative impacts in the Hex River catchment present different issues, roles and responsibilities for industries, government/ regulators and community stakeholders. Practical and cooperative management of cumulative impacts by catchment stakeholders can benefit regional environments and communities of Rustenburg and the North West Province at large. This study demonstrates the usefulness of descriptive statistical techniques for analysis and interpretation of complex data sets, water quality status of the Hex River catchment, influence of the Kroondal Chrome Mine (KCM) waste water to the Hex River catchment, pollution sources and pathways from different activities around Hex River catchment. Best practice water management was recommended to form part of the Kroondal Chrome Mine environmental objects, target and management plan as well as the mine risk profile. Cumulative management dimensions, approaches and/or methods were recommended for all Hex River catchment stakeholders including Department of Water and Sanitation (DWS), mines, farmers, industries and disadvantage communities along the catchment.
153

Bioassessing the impact of water quality on the health and parasite composition of Oreochromis Mossambicus at the Phalaborwa Industrial Complex (PIC) and the barrage (Olifants river) in the Limpopo Province,South Africa.

Ramollo, Phetole Peter 12 1900 (has links)
Thesis (M.Sc)--University of Limpopo, 2008. / Three sites at the Phalaborwa Industrial Complex (PIC) and one site at the Phalaborwa Barrage in the Olifants River were selected to illustrate the possible influence of different water quality parameters on the health and parasite composition of the Mozambique tilapia (Oreochromis mossambicus). Ten fish were collected seasonally at each site using gill nets of different mesh sizes. Selected water quality variables were determined at all the sites to establish possible differences in water quality between the sites. Hosts were examined for mobile ectoparasites, weighed and measured. Blood samples were drawn and skin smears were made. Fish were killed, dissected and all external and internal organs were examined as prescribed in the fish health assessment index (HAI). The condition factor was determined for each fish population from the different sites. All parasites were collected, fixed and preserved using standard methods. A parasite index(PI), abundance, prevalence and mean intensity of the parasite infestations were calculated.Results obtained for the system variables (pH, water temperature and dissolved oxygen) indicated that the pH levels and water temperature fell within the target water quality range (TWQR) for aquatic ecosystems, but the dissolved oxygen recorded during most of the surveys were below 5mg O2 l-1 which may adversely affect the functioning and survival of biological communities. The mean turbidity values were high at sites A, C and D (caused by fine particles such as silt, clay and organic matter). The total dissolved solids (TDS) and the electrical conductivity (EC) were very high at sites B and C throughout the study. The total water hardness and salinity were also very high at sites B and C which can be attributed to the mine tailings water as well as the geology of the region. The cations (calcium, magnesium and potassium) and anions (chloride, fluoride and sulphate) were above the TWQR for aquatic ecosystems at all sites. The fluoride and sodium levels were high at sites B and C. All the major ions contributed significantly to increased levels of TDS, salinity and EC at sites B and C. The nitrogen and phosphate levels indicated that there was an influx of nutrients into the four sampling sites at varying degrees, which can have an effect on eutrophication conditions at the sampling sites. Trace and heavy metal concentrations differed significantly between all the sites. Aluminium, iron and manganese levels were within the TWQR for aquatic ecosystems at all sites. Copper, lead and zinc levels were above the TWQR and sometimes above the chronic and acute effect values for aquatic ecosystems throughout the study (except for lead concentrations at site A). Thus, the mining activities do affect the water quality at sites B and C adversely in terms of the dissolved salts, nutrients and trace and heavy metals (with the water at site C more impacted than that of site B). The toxicity of some metals is however, dependant on the pH (if it changes to be more acidic, some metals may become toxic) and water hardness of the specific site. The lowest population HAI values (indicating healthier fish populations) were mostly recorded from sites A and D (the sites with better water quality) and the highest at site C(the site with poorer water quality) for three surveys. The high HAI values at site C can mainly be attributed to liver discoloration and abnormal haematological parameters. The fish condition factor values ranged from 0.92 to 1.2 with the lowest mean value recorded at site A and the highest mean value recorded at site B. But, the condition factors indicated that the fish from all sites were generally in good health. The values attained for the haematological parameters, liver discolorations, fins (due to parasitic infestation),abnormal gills, as well as the type of parasites present in/on the fish, were the most indicative parameters in the HAI. No abnormalities in the kidneys, opercules and spleens of fish were observed at any of the four sampling sites during this study. Results from the HAI thus indicated that the fish population from site C was more affected by the water quality (with a higher HAI) compared to the fish populations from the other sites. Also, dissimilar water quality at the different sites affected the health of fish differently. The results recorded for the HAI of the different fish populations thus substantiate the results obtained from the water analysis, indicating that fish from site C (with the poorest water quality) was more affected by their environment. The parasites recorded from O. mossambicus were all site-specific and seem to be moderately influenced by the water quality of the different sites. Some groups, e.g. monogeneans were more affected by the differences in water quality than other parasitic groups. The following ectoparasites were recorded: Cichlidogyrus sp. from the gills and Lernaea cyprinacea and Argulus japonicus from the skin. Endoparasites included digenean larvae from the skin (“black spot”) and gills, Neutraclinostomum larvae in the branchial region, Diplostomum metacercariae from the eyes and swimbladder,Diplostomum tregenna from the brain, dilepidid cestode larvae from the liver and outer surface of the intestine, Contracaecum larvae from the body cavity and sinus venosus of the heart, adult acanthocephalans from the intestine, and pentastomatid larvae of two genera (Subtriquetra rileyi and Alofia sp.) from the swimbladder. The hypothesis that the number of ectoparasites will be lower in more polluted water and the number of endoparasites will be higher was well supported for O. mossambicus at all sites except at site C during Spring survey. The PI for endoparasites was higher at all the mine sites (except during Spring) but similar results were also obtained at sites A and D (the less impacted sites). However, all sites tested during this study were impacted to a lesser or higher degree and the PI for endoparasites can thus be higher at all sites. Some ectoparasites (i.e. Lernaea cyprinacea) were present in high numbers at the more polluted site (site C), but the abundance of monogeneans (also ectoparasites) was most of the time lower at sites B and C, suggesting that monogeneans have been strongly influenced by the poorer water quality at these sites. The specific water parameter/s that influenced the abundance of certain ectoparasites needs further investigation which would most probably best be tested under controlled laboratory conditions. In conclusion, all sites sampled during this study were contaminated to some degree with sites B and C more impacted than the other two sites. The water quality results thus confirmed the results obtained using the HAI and to a lesser extent, the PI. The water quality differed between the four sites and had dissimilar impacts on the health of O. mossambicus and the prevalence of some parasites at the different sites. / the National Research Foundation,the Sasol Nitro
154

A comparative study of health of rednose labeo baded on the quantitative health assessment index, bioaccumulation and histopathology in the Olifants Rive

Lebepe, Jeffrey January 2012 (has links)
Thesis (M. Sc. (Zoology)) -- University of Limpopo, 2012 / The Olifants River System is one of the most polluted river systems in Southern Africa. The Olifants River catchment is characterized by large-scale mining, power generation, heavy industry and inadequate domestic sewage treatment. Fish and crocodile kills have become commonplace over the past decade, especially in the upper catchment and Kruger National Park. The present study was carried out at Loskop and Flag Boshielo dams, two major impoundments in the Olifants River. Water and sediment samples were collected at each dam during winter (July 2011) and summer (November 2011), frozen and sent to an accredited water lab for chemical analysis. Atleast fifteen fish specimens from each dam were collected during each survey using gill nets. To evaluate the health of red-nose labeo, (Labeo rosae) in the two dams, fish organs were assessed macroscopically using the fish Health Assessment Index (HAI) protocol and a section of liver tissue and gills were dissected out, frozen and sent to an accredited water lab for metal analysis. The remainder liver samples were fixed in 10% buffered formalin and sent to University of Pretoria Pathology Laboratory for histopathological analysis. The concentration of nutrients and ions were higher at Loskop Dam whereas most metal concentrations were found to be higher at Flag Boshielo Dam. The present study categorised Flag Boshielo Dam as oligotrophic with Loskop Dam being mesotrophic. The concentration of aluminium, copper, antimony, iron, lead, selenium and strontium was higher at Flag Boshielo Dam with manganese, silica and zinc being higher at Loskop Dam. Although the concentrations of these toxic constituents varied, there were no significant differences between localities (p>0.05). The constituents that showed high concentrations in sediment were iron and aluminium. The general trend of accumulation in sediment was as follows: Fe > Al > Si > Mn > Zn > Cu > Sb > Sr > Pb > Se at Loskop Dam whereas at Flag Boshielo Dam was as follows: Fe > Al > Mn > Si > Zn > Cu > Sr > Pb > Sb > Se. The liver generally accumulated higher concentrations of metals than the other tissue. General trend of liver > gills > muscle was reported for Al, Cu, Fe, Pb, Sb, Se, Si and Zn with gills > liver > muscle trend being reported for Mn and Sr at both localities. Macroscopic abnormalities were observed for some gills and liver at both localities. Parasite (Lernaea cyprinacea) induced lesions on the skin and mild erosion on the tail fin of some fish were recorded at Flag Boshielo Dam. Most of the histopathological alterations were common at both localities but hydropic glycogen and hyaline droplets were observed only at Loskop Dam, with haemosiderin being observed at Flag Boshielo Dam. Both quantitative HAI results and histopathology have shown that the fish population from Flag Boshielo Dam are in better condition/health than the population Abstract Abstract Page iv from Loskop Dam. There might be a correlation between the nutrient levels and fish health. The overall ecological state is better at Flag Boshielo Dam than Loskop Dam.
155

Study of selected water quality parameters at Narellan Creek

Xu, Yan Fan, University of Western Sydney, College of Health and Science, School of Biomedical and Health Sciences January 2006 (has links)
A two-year study was conducted at the Narellan Creek Catchment between September 1998 and August 2000. To improve the quality of the water that flows in to the Nepean River, the Harrington Park retention basin was enlarged and rehabilitated from 7.0 ha to 12.0 ha area. This study measured several parameters of water quality to assess the efficiency of the Harrington Park retention basin for water quality improvement. Three sampling sites – the Camden Valley Way (CVW), Harrington Park retention basin (HPK) and Kirkham Lane (KLN) were selected for sample collection. Water flows from CVW to HPK then to KLN and finally to the Nepean River. Rainfall, water level, discharge rate and ambient temperature were recorded at the KLN site while the selected water quality parameters were determined at all the three sites. Low flow samples were manually collected at monthly intervals. An auto-sampler which collected water samples during rain events (for high flow data) was set up at the KLN site. Rising stage samplers which collected water at different water levels during a rain event, was set up at all the sites but data from this device was found to be of limited use due to the varying time lags between the filling of each bottle. Statistical analyses by various measures show that the Harrington Park retention basin played a significant role in improving the upstream and in-stream water quality. These study shows that constructed wetlands like the Harrington Park retention basin has the ability to significantly improve the water quality of a catchment. The water quality improvement is greater at lower water flow rates. / Doctor of Philosophy (PhD)
156

The effects of a detention basin on localized ground-water flux

Green, Jena M. January 2005 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2005. / "December, 2005." Includes bibliographical references. Online version available on the World Wide Web.
157

Respiratory strategies and associated exchange epithelia as determinants on contaminant uptake in aquatic insects

Buchwalter, David B. 05 August 2002 (has links)
Graduation date: 2003
158

Analysis and prediction of beach water quality in Hong Kong with special reference to Big Wave Bay Beach /

Wong, Ho-chuen. January 2009 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (p. [137]-142). Also available in print.
159

Watershed, hydrodynamic, and water quality models for total maximum daily load St. Louis Bay watershed Mississippi

Hashim, Noor Baharim. January 2001 (has links)
Thesis (Ph. D.)--Mississippi State University. Department of Civil Engineering. / Title from title screen. Includes bibliographical references.
160

The use of species diversity and evenness indices for investigating the effects of water quality on diatom communities /

Law, Chi-yuen. January 1982 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1983.

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