Site characterisation of LNAPL-contaminated fractured-rock aquifer
Site characterisation aims to obtain fundamental data needed to describe the subsurface flow pathways and distribution of contaminants. The study describes the application of various geohydrological techniques as complimentary tools to characterise an LNAPL contaminated fractured - rock aquifer on the Beaufort West study area in South Africa. Field investigations were designed to define and determine the properties of the fracture preferential flow paths responsible for LNAPL transportation in a typical Karoo fractured – rock aquifer system. The research places emphasis on the integration of results to maximise the subsurface geological understanding in particular location of fracture features chiefly responsible for facilitating LNAPL migration and distribution. The core and percussion drilling explorations, cross - correlated with borehole geophysics, were valuable for geological subsurface investigations in particular locations of bedding fractures, which are often associated with high hydraulic conductive flow zones. Tracer and pump tests were conducted to determine hydraulic and mass transport parameters respectively. Hydraulically conductive bedding plane fracture flow zones were identified by integrating results from the geological core logs, borehole geophysics and aquifer tests. The chemical characterisation of the study area was conducted by means of organic hydrocarbon, inorganic water analyses and volatile organic carbon measurements in the soil during air percussion drilling. Based on the findings, the hydrogeological structure of the formation was conceptualised as a fractured sandstone aquifer, characterised by bedding plane fracture preferential flow paths at contact areas, with shale and mudstone formations. The study findings demonstrate the merit and value in the application of various geohydrological tools to complement one another for optimised site understanding. The findings and recommendations of the case study are not necessarily confined to LNAPL contaminated fractured - rock aquifers, but may also be applicable to other types of contaminants in fractured - rock aquifer formations.
Showing items related by title, author, creator and subject.
Characterisation of the physiological, biochemical and molecular responses of sorghum to drought stress Goche, Tatenda (University of the Free State, 2018-11)Drought is a major threat to global food security due to its detrimental effects on plant growth, productivity and yield quality. Many climatic models are predicting the increasing duration and severity of drought episodes. ...
Preparation and characterisation of biodegradable polymer nanocomposites with magnesium hydroxide (Mg(OH)2) and functionalized titania (f-TiO2) nanoparticles as fillers Mukwada, Lesley Tsitsi (University of the Free State, 2018-06)Magnesium hydroxide (Mg(OH)2) (1, 3, 5 and 10 wt.%) and (3-aminopropyl)-trimethoxysilane functionalized titania (APTMS-TiO2) (1, 3 and 5 wt.%) nanoparticles were added to PLA, PCL and their blends (70/30, 50/50 and 30/70) ...
Synthesis and characterisation of ferrocenylalkoxy-functionalised polyphosphazenes for biomedical applications Govender, Maheshini (University of the Free State, 2020-01)