 Abstract | Wastewater derived from domestic or industrial sources can contain a diverse range of dissolved and suspended chemical and/or biological contaminants (e.g. nutrients, heavy metals, pharmaceuticals, pathogens) and can present a serious risk to human health or ecosystems if not disposed of appropriately.
An effective and commonly used method for treating many types of wastewater is to detain the effluent stream in large and shallow lined ponds or impoundments for a period of time. Such ponds are typically termed 'waste stabilisation ponds' (WSP) or 'waste stabilisation lagoons'.
Such systems provide a contained environment that allows naturally occurring algae and photosynthetic bacteria to grow profusely in response to light from the sun. The abundant oxygen produced by this photosynthetic activity allows aerobic bacteria to flourish and oxidise organic and inorganic nutrients. Such conditions can also result in dramatic declines in the concentration of pathogenic organisms.
As photosynthesis ensures maintenance of aerobic conditions within pond, a great deal of research has been undertaken to better understand the factors that determine the oxygen dynamics, productivity and ecology of algal/bacterial assemblages present in these systems.
The research presented in this thesis was undertaken with the goal of better characterising relations between irradiance, algal oxygen dynamics and productivity. Such factors are basic to the cycling of energy in algal-based wastewater treatment systems as well as natural aquatic ecosystems. |
