Aquatic environments are increasingly exposed to a myriad of organic chemicals as human populations expand their environmental influence. Biodegradation of organic chemicals is recognised as a key process in chemical removal from environments. However, our understanding of biodegradation rates for the multitude of chemicals measured in environments is limited, thus introducing large uncertainties into chemical exposure assessments. In addition, the standardised laboratory regulatory test for assessing the biodegradation of chemicals in aquatic environments, namely the OECD 309 simulation test, has been criticised with respect to its environmental relevance. In response, researchers have systematically investigated alternative methods and applied such methods in order to address other gaps in the biodegradation literature including spatial and temporal variability. As such, environmentally relevant studies have focused on riverine environments in temperate and mediterranean regions. There is a notable gap in our understanding of spatial variability in diverse aquatic environments such as reservoirs, estuaries, and marine environments, particularly in sub-tropical and tropical regions. In addition, our understanding of how biodegradation rates derived from laboratory experiments translate to biodegradation occurring in the field is limited. Thus, this thesis aims to quantify the spatial variability in the biodegradation rate constants of organic chemicals across a range of distinct aquatic environments using a modified laboratory experiment; compare this dataset against an equivalent study conducted in European rivers; and interrogate these laboratory-derived rate constants in relation to rate constants derived in the field.
Please note this is a student progress review presentation by Lily Weir