HR: 1330h
AN: NB33O-04    [Abstracts]
TI: Diel Patterns in Discharge and Water Chemistry in an Urban River.
AU: * Runck, C
EM: crunck@ben.edu
AF: Department of Biological Sciences, Benedictine University, 5700 College Road, Lisle, IL 60532-0900 United States
AB: Water chemistry variables were measured during base-flow conditions at hourly intervals over 24 h, once in July and once in August 2003, in the East Branch of the DuPage River (EBDP). The EBDP flows for its entire 56 km length through one of the most heavily urbanized areas in Illinois and receives effluent from 8 wastewater treatment plants (WWTP). Discharge in EBDP varied by an average of 45% during a 24 h period, with minimum discharge occurring around 12:00 h and maximum around 21:00 h. Water chemistry variables tended to follow the diel pattern in stream discharge. Diel differences between minimum and maximum values for some water chemistry variables were substantial, e.g., SRP varied by 1.1 mg/L and NO₃ varied by 3.5 mg/L, and maximum values occurred between 23:00 and 3:00 h. The influence of benthic metabolism and sediment adsorption-desorption on diel patterns in SRP and NO₃ in EBDP are under investigation. The results of this study suggest that the diel pattern of discharge related to WWTP operation must be considered to accurately monitor water quality variables in urban rivers.
DE: 1806 Chemistry of fresh water
DE: 1860 Runoff and streamflow
DE: 1871 Surface water quality
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly