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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

An assessment of water quality along Mukuvisi River, Harare, Zimbabwe

Chimuriwo, Blessing 05 1900 (has links)
Human activities such as urbanisation, sewage treatment, industrialisation and agriculture represent major human interference in water resources. The water resources are affected both quantitatively as well as qualitatively by these activities. The impact of human interference in the Mukuvisi River catchment hydrology was studied by determining the concentration values of eight selected physico - chemical and biological parameters. These are pH, temperature, total nitrates, total phosphates, Dissolved Oxygen, Biological Oxygen Demand, lead, copper and Total Faecal Coliform Count. Seven sites were sampled along the river, from up the river in Mukuvisi woodlands up to the point where the river discharges into Lake Chivero. Analysis of the results obtained was undertaken using SPSS (paired sample T test) and descriptive graphs were drawn using Microsoft Excel 2010. Nitrates, phosphates, copper, lead and Total Faecal Coliform Counts were found to be higher than the Zimbabwe National Water Authority (ZINWA) maximum and World Health Organisation, 2011 (WHO) permissible standards from site 3 to site 7. Site 6 recorded the highest concentrations of all the measured parameters, except for pH and Dissolved Oxygen. Mean DO and BOD concentrations were 2.53 mg/l and 40 mg/l respectively at site 6. Mean total nitrates were 17.5 mg/l at site 6 above the ZINWA and WHO threshold of 10 mg/l. Site 6 also recorded a mean total phosphate of 5.9 mg/l which was above the ZINWA and WHO threshold of 0.5 mg/l. Mean TFCC was 992.6 mpn100ml-1 higher than the threshold of nil according to ZINWA and WHO threshold. Site 3 recorded the mean DO and TFCC of 2.4 mg/l and 2.80 mpn100ml-1 respectively. Site 2 had the lowest mean TFCC concentrations of 2.80 mpn100ml-1, which did not differ significantly from the WHO and ZINWA threshold of nil at p<0.05. The quality of water in the river varied from site to site in direct relation to the intensity and type of human activities along the river course. Levels of all the water quality indicators increased after discharge from the Firle sewage treatment plant at site 6 with the exception of temperature and pH. Sewage effluents, agricultural runoff and industrial effluents were found to be responsible for the high nutrient levels and high metal concentrations in the river which in turn reduced DO levels and increased BOD / College of Agriculture and Environmental Sciences / M. Sc. (Environmental Science)
2

Kvalita vod v povodí Mastníku a jeho vliv na Slapskou nádrž / Water quality in the Mastnik catchment area and its influence on Slapy reservoir

Mrkva, Luboš January 2013 (has links)
Water quality in the Mastnik catchment area and it`s influence on Slapy reservoir Abstract Despite major investments in remediation of waste water and reduction of fertilizers the quality of surface water on small rivers in agricultural and rural regions of the Czech Republic is still very low. Among the problematic rivers is also the river Mastník. This river runs through agricultural area of the Central Bohemian Uplands and as a right-hand side tributary it flows into the Vltava river, in particular to Slapy reservoir. According to the data of concentration of indicators coming from monitored profiles of the State public enterprise Povodí Vltavy which were completed by our own monitoring profile the quality of water has been analyzed. Furthermore, the effect of Mastník on the water quality in Slapy reservoir has been evaluated. It was discovered that the steps that are being taken, mainly construction of sewage treatment plants, are leading to gradual improvement of quality of the surface water. Nowadays the final quality of water is influenced by growing concentration of chlorophyll. This growth is caused by warmer waters and that leads to higher eutrofisation of rivers in the catchment area. The most significant eutrofisation is showing in the creek of Mastník where it's affected by Slapy reservoir. In...

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