HR: 08:30h
AN: B51F-03    [Abstracts]
TI: Dissolved Organic Matter Dynamics in two Suburban Catchments in NE England
AU: * Baker, A
EM: a.baker.2@bham.ac.uk
AF: University of Birmingham, Edgbaston, Birmingham, B15 2TT United Kingdom
AU: Simpson, E
EM: ellie.simpson@environment-agency.gov.uk
AF: Environment Agency, Rio House, Aztec West, Bristol, B32 4UD United Kingdom
AU: Bryant, C
EM: c.bryant@nercrcl.gla.ac.uk
AF: NERC Radiocarbon Laboratory, Scottish Enterprise Technology Park Rankine Avenue East Kilbride , Glasgow, G75 0QF United Kingdom
AB: Recent advances in fluorescence spectrophotometry enable rapid and optically precise analysis of river dissolved organic matter (DOM). In this study we investigate the potential of detecting river pollution associated with urban expansion (cross connected sewerage; overloading of combined sewer overflows (CSOs), land use change) using fluorescence and absorbance spectrophotometry, paired with conventional geochemistry, microbiological analyses and 14C/13C isotope fingerprinting of dissolved organic matter, in two small, rural-urban fringe catchments in NE England over the period 2002-present. In the United Kingdom, `suburbia' (post 1945AD) is distinguished by separate sewerage systems and associated issues of cross connections. Results indicate: (1) suburban catchments have a seasonal trend in DOM fluorescence, with a maximum of tryptophan-like fluorescence in summer low flow, indicative of an increased proportion of cross connected sewer inputs, with a statistically significant inverse relationship with discharge. Older `urban' catchments with CSOs exhibit an opposite seasonality, with combined sewerage overflows occurring in winter at high flow due to CSO discharge. (2) Sampling cross connected storm drains for both Escherichia coli. and fluorescence demonstrates a statistically significant relationship. This finding matches laboratory microbial cultures, which have demonstrated that a wide range of environmentally relevant microbes exhibit tryptophan-like fluorescence, and suggests that when coliforms dominate a river or wastewater microbial community then fluorescence intensity could potentially be employed to monitor faecal coliforms in urban waters. (3) 14C/13C fingerprinting of DOM in three contrasting sub-catchments separates urban and industrial DOM sources through positive 13C and `old' 14C.
UR: http://www.purenorthsea.com
DE: 0432 Contaminant and organic biogeochemistry (0792)
DE: 0478 Pollution: urban, regional and global (0345, 4251)
DE: 0493 Urban systems
DE: 0496 Water quality
DE: 0545 Modeling (4255)
SC: Biogeosciences [B]
MN: Fall Meeting 2005