Dissolved organic matter signatures in urban surface waters: spatio-temporal patterns and drivers

[摘要] Advances in analytical chemistry have facilitated the characterization ofdissolved organic matter (DOM), which has improved understanding of DOMsources and transformations in surface waters. For urban waters, however,where DOM diversity is likely to be high, the interpretation of DOMsignatures is hampered by a lack of information on the influence of landcover and anthropogenic factors such as nutrient enrichment and release oforganic contaminants. Here we explored the spatio-temporal variation in DOMcomposition in contrasting urban water bodies, based on spectrophotometryand fluorometry, size-exclusion chromatography, and ultrahigh-resolution massspectrometry, to identify linkages between DOM signatures and potentialdrivers. The highly diverse DOM we observed distinguished lakes and ponds,which are characterized by a high proportion of autochthonous DOM, fromrivers and streams where allochthonous DOM is more prevalent. Seasonalvariation in DOM composition was apparent in all types of water bodies,apparently due to interactions between phenology and urban influences, suchas nutrient supply, the percentage of green space surrounding the waterbodies and point source pollution. Optical DOM properties also revealed theinfluence of effluents from wastewater treatment plants, suggesting thatsimple optical measurements can be useful in water quality assessment andmonitoring, providing information about processes both within water bodies and in theircatchments.

[学科分类] 大气科学