Landfill emissions are the major environmental impact associated with the landfilling of solid wastes. These emissions which are mainly gases and leachate are a result of the anaerobic biochemical breakdown of the waste in landfills. The long term emissions from these solid wastes in landfills can be significantly reduced by Mechanical Biological Pretreatment of the waste prior to landfilling. Mechanical Biological Pretreatment of solid wastes is aimed at reducing the long term polluting potential from landfills through accelerated stabilization of the organic constituent material present in the waste body by biological degradation before the waste is placed in landfills. This research is part of a broader investigation on the applicability of Mechanical Biological Pretreatment of solid wastes prior to disposal in the South Africa Waste Management context. General waste disposed at Bisasar Road Landfill Site in Durban which has been pretreated for 16 weeks in passively aerated windrows was collected and screened using a rotatory drum screen to generate an over-sieved waste fraction with particles of diameter greater than 50mm and an under-sieved waste fraction characterized by particles diameter less than 50mm. The long term behavior of these heavily pretreated wastes was then simulated using large anaerobic reactors (Lysimeter) in relation to grain size distribution. A third lysimeter containing general waste without pretreatment collected from Bisasar Road Landfill Site was also set up in order to study the effect of pretreatment on solid waste samples. The results of this research were then used to make recommendation on the appropriateness of Mechanical Biological in the South Africa Waste Management context. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007

Spatial and temporal variation in inorganic contaminant concentration and distribution in a landfill leachate plume is examined to determine the mechanisms responsible for the observed variation, and to provide an assessment of the implications of this variation with respect to the interpretation of monitoring data, specifically with regards to its application to geochemical modelling. An integrated approach to field investigation was utilised in this study, including sample collection from a network of standard and bundled piezometers, surface and borehole geophysical investigation techniques, and a manometer board for the measurement of hydraulic head in bundled piezometers. Nine groundwater sampling events were conducted over a 12 month period, with sample analyses comprising field measurement of water quality parameters and redox sensitive elements, and laboratory analysis for major and trace elements and stable isotopes (??18O, ??2H, ??13C-DIC, ??15N). The vertical position of the centre of mass of the leachate plume was observed to vary up to 2 metres between monitoring events, and concentrations of key indicator parameters were observed to fluctuate by as much as 160%. The electrical images created by surface resistivity transects along a groundwater flow path between the landfill and a groundwater-fed pond a short distance downgradient suggest a plume configuration characterised by discrete pulses of concentrated leachate migrating in a conservative manner between the landfill and the pond. It is hypothesized that these leachate slugs are flushed into the aquifer during sustained periods of rainfall, presumed to be a significant driver of leachate mobilisation into the underlying aquifer. The most significant hydrogeochemical processes affecting contaminant mobilisation, transport and attenuation in the leachate-impacted shallow aquifer included microbial degradation of organic waste, dissolution of inorganic waste, ion exchange, precipitation of sulfide and carbonate minerals, mixing with rainfall recharge along flow path, and redox transformations along the plume fringe. These processes are supported by hydrogeochemical data analysis, and generally agree with the results of inverse geochemical modelling. While analysis of detailed groundwater monitoring appears to provide a plausible description of the plume dynamics, the results of the electrical resistivity transects indicates a more varied and complex plume configuration than is suggested by the borehole data alone. This integration of investigation techniques underscores the inherent inadequacy of even a high-resolution monitoring well network to accurately describe the full extent of variation in time and space within a contaminant plume, even in a relatively simple aquifer environment, and accentuates the potentially significant limitations of site-scale hydrogeochemical interpretation based solely on borehole monitoring data.

Spatial and temporal variation in inorganic contaminant concentration and distribution in a landfill leachate plume is examined to determine the mechanisms responsible for the observed variation, and to provide an assessment of the implications of this variation with respect to the interpretation of monitoring data, specifically with regards to its application to geochemical modelling. An integrated approach to field investigation was utilised in this study, including sample collection from a network of standard and bundled piezometers, surface and borehole geophysical investigation techniques, and a manometer board for the measurement of hydraulic head in bundled piezometers. Nine groundwater sampling events were conducted over a 12 month period, with sample analyses comprising field measurement of water quality parameters and redox sensitive elements, and laboratory analysis for major and trace elements and stable isotopes (??18O, ??2H, ??13C-DIC, ??15N). The vertical position of the centre of mass of the leachate plume was observed to vary up to 2 metres between monitoring events, and concentrations of key indicator parameters were observed to fluctuate by as much as 160%. The electrical images created by surface resistivity transects along a groundwater flow path between the landfill and a groundwater-fed pond a short distance downgradient suggest a plume configuration characterised by discrete pulses of concentrated leachate migrating in a conservative manner between the landfill and the pond. It is hypothesized that these leachate slugs are flushed into the aquifer during sustained periods of rainfall, presumed to be a significant driver of leachate mobilisation into the underlying aquifer. The most significant hydrogeochemical processes affecting contaminant mobilisation, transport and attenuation in the leachate-impacted shallow aquifer included microbial degradation of organic waste, dissolution of inorganic waste, ion exchange, precipitation of sulfide and carbonate minerals, mixing with rainfall recharge along flow path, and redox transformations along the plume fringe. These processes are supported by hydrogeochemical data analysis, and generally agree with the results of inverse geochemical modelling. While analysis of detailed groundwater monitoring appears to provide a plausible description of the plume dynamics, the results of the electrical resistivity transects indicates a more varied and complex plume configuration than is suggested by the borehole data alone. This integration of investigation techniques underscores the inherent inadequacy of even a high-resolution monitoring well network to accurately describe the full extent of variation in time and space within a contaminant plume, even in a relatively simple aquifer environment, and accentuates the potentially significant limitations of site-scale hydrogeochemical interpretation based solely on borehole monitoring data.

Spatial and temporal variation in inorganic contaminant concentration and distribution in a landfill leachate plume is examined to determine the mechanisms responsible for the observed variation, and to provide an assessment of the implications of this variation with respect to the interpretation of monitoring data, specifically with regards to its application to geochemical modelling. An integrated approach to field investigation was utilised in this study, including sample collection from a network of standard and bundled piezometers, surface and borehole geophysical investigation techniques, and a manometer board for the measurement of hydraulic head in bundled piezometers. Nine groundwater sampling events were conducted over a 12 month period, with sample analyses comprising field measurement of water quality parameters and redox sensitive elements, and laboratory analysis for major and trace elements and stable isotopes (??18O, ??2H, ??13C-DIC, ??15N). The vertical position of the centre of mass of the leachate plume was observed to vary up to 2 metres between monitoring events, and concentrations of key indicator parameters were observed to fluctuate by as much as 160%. The electrical images created by surface resistivity transects along a groundwater flow path between the landfill and a groundwater-fed pond a short distance downgradient suggest a plume configuration characterised by discrete pulses of concentrated leachate migrating in a conservative manner between the landfill and the pond. It is hypothesized that these leachate slugs are flushed into the aquifer during sustained periods of rainfall, presumed to be a significant driver of leachate mobilisation into the underlying aquifer. The most significant hydrogeochemical processes affecting contaminant mobilisation, transport and attenuation in the leachate-impacted shallow aquifer included microbial degradation of organic waste, dissolution of inorganic waste, ion exchange, precipitation of sulfide and carbonate minerals, mixing with rainfall recharge along flow path, and redox transformations along the plume fringe. These processes are supported by hydrogeochemical data analysis, and generally agree with the results of inverse geochemical modelling. While analysis of detailed groundwater monitoring appears to provide a plausible description of the plume dynamics, the results of the electrical resistivity transects indicates a more varied and complex plume configuration than is suggested by the borehole data alone. This integration of investigation techniques underscores the inherent inadequacy of even a high-resolution monitoring well network to accurately describe the full extent of variation in time and space within a contaminant plume, even in a relatively simple aquifer environment, and accentuates the potentially significant limitations of site-scale hydrogeochemical interpretation based solely on borehole monitoring data.

This study investigates the occurrence and chemical composition of leachate at Clayton South and Brooklyn Municipal waste landfills in Melbourne, Victoria. Both are ‘modern’ municipal waste landfills, being engineered and managed consistent with current regulatory requirements. These landfills accept only putrescible and solid inert waste, but not soluble chemical, hazardous, liquid or prescribed industrial waste. (For complete abstract open document)

Spatial and temporal variation in inorganic contaminant concentration and distribution in a landfill leachate plume is examined to determine the mechanisms responsible for the observed variation, and to provide an assessment of the implications of this variation with respect to the interpretation of monitoring data, specifically with regards to its application to geochemical modelling. An integrated approach to field investigation was utilised in this study, including sample collection from a network of standard and bundled piezometers, surface and borehole geophysical investigation techniques, and a manometer board for the measurement of hydraulic head in bundled piezometers. Nine groundwater sampling events were conducted over a 12 month period, with sample analyses comprising field measurement of water quality parameters and redox sensitive elements, and laboratory analysis for major and trace elements and stable isotopes (??18O, ??2H, ??13C-DIC, ??15N). The vertical position of the centre of mass of the leachate plume was observed to vary up to 2 metres between monitoring events, and concentrations of key indicator parameters were observed to fluctuate by as much as 160%. The electrical images created by surface resistivity transects along a groundwater flow path between the landfill and a groundwater-fed pond a short distance downgradient suggest a plume configuration characterised by discrete pulses of concentrated leachate migrating in a conservative manner between the landfill and the pond. It is hypothesized that these leachate slugs are flushed into the aquifer during sustained periods of rainfall, presumed to be a significant driver of leachate mobilisation into the underlying aquifer. The most significant hydrogeochemical processes affecting contaminant mobilisation, transport and attenuation in the leachate-impacted shallow aquifer included microbial degradation of organic waste, dissolution of inorganic waste, ion exchange, precipitation of sulfide and carbonate minerals, mixing with rainfall recharge along flow path, and redox transformations along the plume fringe. These processes are supported by hydrogeochemical data analysis, and generally agree with the results of inverse geochemical modelling. While analysis of detailed groundwater monitoring appears to provide a plausible description of the plume dynamics, the results of the electrical resistivity transects indicates a more varied and complex plume configuration than is suggested by the borehole data alone. This integration of investigation techniques underscores the inherent inadequacy of even a high-resolution monitoring well network to accurately describe the full extent of variation in time and space within a contaminant plume, even in a relatively simple aquifer environment, and accentuates the potentially significant limitations of site-scale hydrogeochemical interpretation based solely on borehole monitoring data.

Spatial and temporal variation in inorganic contaminant concentration and distribution in a landfill leachate plume is examined to determine the mechanisms responsible for the observed variation, and to provide an assessment of the implications of this variation with respect to the interpretation of monitoring data, specifically with regards to its application to geochemical modelling. An integrated approach to field investigation was utilised in this study, including sample collection from a network of standard and bundled piezometers, surface and borehole geophysical investigation techniques, and a manometer board for the measurement of hydraulic head in bundled piezometers. Nine groundwater sampling events were conducted over a 12 month period, with sample analyses comprising field measurement of water quality parameters and redox sensitive elements, and laboratory analysis for major and trace elements and stable isotopes (??18O, ??2H, ??13C-DIC, ??15N). The vertical position of the centre of mass of the leachate plume was observed to vary up to 2 metres between monitoring events, and concentrations of key indicator parameters were observed to fluctuate by as much as 160%. The electrical images created by surface resistivity transects along a groundwater flow path between the landfill and a groundwater-fed pond a short distance downgradient suggest a plume configuration characterised by discrete pulses of concentrated leachate migrating in a conservative manner between the landfill and the pond. It is hypothesized that these leachate slugs are flushed into the aquifer during sustained periods of rainfall, presumed to be a significant driver of leachate mobilisation into the underlying aquifer. The most significant hydrogeochemical processes affecting contaminant mobilisation, transport and attenuation in the leachate-impacted shallow aquifer included microbial degradation of organic waste, dissolution of inorganic waste, ion exchange, precipitation of sulfide and carbonate minerals, mixing with rainfall recharge along flow path, and redox transformations along the plume fringe. These processes are supported by hydrogeochemical data analysis, and generally agree with the results of inverse geochemical modelling. While analysis of detailed groundwater monitoring appears to provide a plausible description of the plume dynamics, the results of the electrical resistivity transects indicates a more varied and complex plume configuration than is suggested by the borehole data alone. This integration of investigation techniques underscores the inherent inadequacy of even a high-resolution monitoring well network to accurately describe the full extent of variation in time and space within a contaminant plume, even in a relatively simple aquifer environment, and accentuates the potentially significant limitations of site-scale hydrogeochemical interpretation based solely on borehole monitoring data.

Thesis (M.S.)--Ohio University, August, 1994. / Title from PDF t.p.

Thesis (Ph. D.)--Lehigh University, 2005. / Includes vita. Includes bibliographical references (leaves 232-245).

Thesis (M.S.)--Florida State University, 2005. / Advisor: Dr. Tarek Abichou, Florida State University, College of Engineering, Dept. of Civil and Environmental Engineering. Title and description from dissertation home page (viewed June 8, 2005). Document formatted into pages; contains ix, 62 pages. Includes bibliographical references.