The deep row trenching of ventilated improved pit-latrine (VIP) and waste water treatment works (WWTW) sludge is a unique alternative cost effective land application method that will prevent odour and health problems and may permit higher application rates than surface application. The goal of this research is to assess the environmental consequences of employing deep row incorporation of VIP and WWTW sludge to forest plantation lands for the production of Eucalyptus dunnii. The objectives are to monitor, define and quantify the fluxes of nutrients (nitrate and phosphorus) from the buried sludge to the surrounding soils, groundwater and surface water. The WWTW study was conducted on a forestry plantation located near the Shafton Karkloof Falls, about 10 km from Howick in the KwaZulu-Natal province of South Africa. The land for the research is owned by SAPPI, a timber plantation company. The trenching was done with stockpiled secondary sludge from Umgeni WWTW in Howick. VIP sludge trenching was done at the Umlazi E-ponds site in Durban owned by EThekwini Municipality. This site was formally used as a wastewater treatment plant sludge drying bed. The treatment works comprised three oxidation ponds and was operated until 1999, when it was decommissioned after a heavy flood, resulting in damage to the oxidation ponds. The sites were instrumented with wetting front detectors, piezometers and boreholes for collection and analysis of leachate from which were determined subsurface loss of nitrogen and phosphorus. Soil water status and groundwater levels were also monitored. Simulation of the process of water, nitrate and phosphorus transport was performed in order to aid the development of the sustainable management methodologies for land application and the trenching of VIP/WWTW sludge. The study focuses on the entrenched sludge to determine the concentration of pollutants, monitorchanges in concentration over time and to monitor the movement of solutes and any change taking place in the surrounding soil water and groundwater. The results contribute to the development of guidelines and protocols for VIP/WWTW sludge handling and trenching in South Africa. It was demonstrated that the nutrient migration processes can be approximated with the conceptual simplifications of the inputs to the model based on field evidence, soil survey data and applicable literature. In the study, it was found that high concentrations of nutrients were evident in the water infiltrating into and through the sludge in all trench types. The nitrate concentration median values in the trenches were 234mg/l and 36mg/l for SAPPI and Umlazi respectively, while the recorded median value for phosphorus was 1.0mg/l and 3.5mg/l for SAPPI and Umlazi respectively. However the effect of vertical seepage of nutrients, into the deep aquifer in fractured rock has not been observed in the deep borehole with the nitrate concentration median values at 5mg/l and 0.6mg/l for SAPPI and Umlazi respectively, while the phosphorus concentration median values were 0.03mg/l and 0.15mg/l for SAPPI and Umlazi sites respectively. The study revealed significant differences between the sandy alluvial site at Umlazi and the shale dolorite site at the SAPPI forests. Where an unsaturated zone below the entrenched sludge existed at the Umlazi site, nutrient transport was retarded, whereas in the shales of the SAPPI site, preferential delivery flowpaths transported high concentrations of nutrients rapidly from the entrenched sludge to the base of the hillslope. These mechanisms needed to be treated differently in the simulation exercise. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Water treatment residue (WTR), a by-product of the water treatment process, consists primarily of precipitated hydroxides of the coagulants used in the water treatment process, along with sand, silt, clay, humic compounds, and dissolved organic matter. It is usually disposed of by landfill, a technology with numerous problems that include dwindling landfill capacity, extensive dewatering requirements for the WTRs, high costs of transportation, and potential liability for landfill clean-up. Therefore, land disposal (or land treatment) presents a popular alternative disposal method based on the principle that the physical, chemical, and microbial properties of the soil can be used to assimilate applied waste without inducing any negative effects on soil quality. The objective of this study was to investigate the effects of land disposal of the WTR generated by Umgeni Water, a local water treatment authority, on soil quality. These effects were investigated using depth samples from soil profiles of Westleigh and Hutton soil forms at field trials located at Ukulinga Research Farm, near Pietermartizburg and Brookdale Farm, Howick, KwaZulu-Natal, South Africa, respectively. Four rates of WTR (0, 80, 320, and 1280Mg ha-1 incorporated into the soil) were investigated at both trials, in addition to mulched treatments at rates of 320 and 1280Mg ha-1 at Brookdale only. Sampling of plots was carried out in September 2001 and May 2002, and all treatments were investigated under fallow and grassed cultivation. Laboratory measurements used to assess soil quality included pH, electrical conductivity (EC), organic carbon (QC), and microbial activity using f1uorescein diacetate (FDA) hydrolysis. At both trials in September 2001 WTR-amended plots displayed higher pH in the 0-200mm soil in comparison to the controls, whereas by May 2002 pH had returned to the condition of the controls. Addition of WTR at Ukulinga resulted in higher QC in September 2001, but in May 2002 this was similar to the controls. However, at Brookdale QC was unaffected by WTR. At Ukulinga and Brookdale the effect of WTR on EC was variable, and microbial activity in the soil profile was unaffected by WTR addition. Observations at Ukulinga and Brookdale reflected long term changes (3 and 5 years, respectively) to soil quality following WTR addition. To examine the initial changes in soil quality a laboratory experiment was set up using the field trial soils. Research objectives were also extended to include WTRs from Rand Water (Johannesburg), Midvaal Water Company (Stilfontein), Amatola Water (East London), and two samples from the Faure Water Treatment Plant (near Cape Town). The second Faure sample (Faure2 ) was collected when blue green algal problems were experienced at the plant. The measurements used to investigate these short term effects on soil quality were soil pH, EC, and microbial activity as indicated by respiration rate. Each of the WTRs added to the Hutton and Westleigh soils increased soil pH by varying increments, and the higher the WTR application rate, the higher was the pH recorded. With the exception of the Rand and Umgeni WTRs that clearly increased soil EC, the effect of the otherWTRs on EC was variable. The Faure1 and Amatola WTRs appeared to have no effect on microbial activity, whereas the Umgeni, Rand, Midvaal, and Faure2 WTRs stimulated microbial activity by Day 2 following the addition of WTR, but this had declined by Day 14. As for pH, higher microbial activity was recorded at higher WTR application rates. Changes in microbial community structure of the Hutton soil only, following the addition of WTR were examined using denaturing gradient gel electrophoresis (DGGE) analysis. Community profiles of the different WTRs proved to be markedly different. However, WTR-amended soil retained banding patterns consistent with the control soil indicating that dominant populations in the Hutton soil had been retained. The field trials indicated that long term effects of land disposal of WTR were not detrimental to the measured indicators of soil quality namely, pH, EC, QC, and microbial activity. The laboratory assessments of the short term response of the Hutton and Westleigh soil forms to WTR addition suggested that the tested variables were altered by WTR, but not significantly changed to the detriment of soil quality. Microbial community analysis indicated that the community structure of the Hutton soil was not significantly altered by WTR amendments. Present findings provide no evidence to suggest that land disposal of WTR is detrimental to soil quality. It is therefore regarded as a feasible disposal option although there are some aspects that should be investigated further. These include investigations into rhizosphere/microbial interactions and the feasibility of growing cash crops. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

No description available.

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 84-87).

Thesis (M.Env.St.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 2000. / Bibliography: leaves 84-91.

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 148-158). Also available in electronic format on the Internet.

Thesis (M.P.H.)--University of Michigan, 1947.

Thesis (M.S.P.H.)--University of Michigan, 1939.

Thesis (M.Sc. (Industrial Ecology and Environment))--Mahidol University, 2008.

Thesis (Ph.D.)--Flinders University, School of Medicine, Dept. of Environmental Health. / Typescript bound. Includes bibliographical references: (leaves 650-698) Also available online.