The distribution of short chain carboxylic acids in eutrophic drainage channels

摘要

The concentration of the C2–C5carboxylic acids in the water column and sediment of shallow, eutrophic, drainage channels (Lewes Brooks, UK) were measured by gas chromatography. The concentrations of these acids were negatively correlated with dissolved oxygen. The highest concentrations of acetate (up to 200 μM), propanoate (up to 38 μM) and butanoate (up to 1.2 μM) were measured during the summer in the water above the sediment, which became hypoxic during this period. Both acetate and propanoate concentrations declined at night. High concentrations of the acids were also recorded in reedbeds, which were also hypoxic. Only acetate was detected in the sediment pore water (up to 168 μM). Its concentration declined during the autumn and winter and with increasing depth within the sed