title: Evaluation of cycling patterns of dissolved oxygen in a tropical lake as an indicator of biodegradable organic pollution.
abstract: Dissolved oxygen cycling patterns in a tropical lake (Weija Lake) were shown to be useful as a potential indicator of biodegradable organic pollution, by dosing with liquid malt to give an additional organic burden of 2.5 and 5.0 mg l-1 TOC, and monitoring the DO values continuously for 140 h. These loadings were added to water columns (in tubes) suspended from a raft in a lake in south-east Ghana. The addition of organic pollution burden to the lake water produced two main effects: the mean DO value was lowered, and the amplitude of the DO cycle decreased as organic loading increased from 2.5 to 5.0 mg l-1 TOC. There was also an indication of heterotrophic respiration associated with organic inputs for the 5.0 mg l-1 added TOC suggesting a P/R ratio of well below 1.0. Taking the results of a DO cycling computer model together with those from the lake raft experiments, it can be concluded that dissolved oxygen cycles can be a good indicator of biodegradable organic pollution load.
authors.affiliation: Department of Chemistry, University of Aberdeen, UK.
authors.forename: O D
authors.initials: OD
authors.lastname: Ansa-Asare
authors.forename: I L
authors.initials: IL
authors.lastname: Marr
authors.forename: M S
authors.initials: MS
authors.lastname: Cresser
mesh_terms: D001673:Biodegradation, Environmental; D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis; D005869:Ghana; D008962:Models, Theoretical; D010100:Oxygen / Q000032:analysis*; D014329:Tropical Climate; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D010100:Oxygen