Berretta,C. and Sansalone,J.(2011): Speciation and transport of phosphorus in source area rainfall-runoff. Water Air Soil Pollut., 222, 351-365.

『表面域降雨−流出におけるリンの化学種と移動』


Abstract
 Phosphorus (P) delivered by urban rainfall-runoff partitions and speciates during the transport process. This study examines transport and speciation of P in rainfall and runoff across 15 wet weather events from a paved source area dominated by biogenic loads and to a lesser degree, anthropogenic loads. The mean and median event-based source area total phosphorus is 3.6 and 3.5 mg/l, respectively. The mean and median event-based source area dissolved fraction (fd) are 0.31 and 0.32 illustrating that P is predominately bound to particulate matter fractions. The majority of events across the monitoring campaign produce a weak mass-limited transport of dissolved phosphorus (DP). With respect to the DP fraction in runoff (pH range of 6.4 to 8.6), the dominant species are orthophosphates (HPO4-2 and H2PO4-) which account for more than 90% of DP mass. The order of species predominance is consistently HPO4-2≒H2PO4->>CaHPO4>MgHPO4. With rainfall pH ranging from 4.2 to 4.9 and a fd≒1.0, H2PO4- accounts for 95% to 99% of DP in rainfall. Despite the inherent variability of a large dataset (362 samples across 15 events) the speciation of DP is influenced primarily by pH, with a range from 4.2 (rainfall) up to 8.6 (runoff) that results in an order of magnitude change in P species concentration and determines the order between the dominant orthphosphate species. For this source area, the role of alkalinity, dissolved organic carbon and partitioning on DP speciation are minor compared to the influence of pH.

Keywords: Urban runoff; Stormwater phosphorus; Eutrophication; Speciation; Partitioning; Nonpoint sources』

1. Introduction
2. Methodology
 2.1. Source area catchment and sampling and analysis methods
 2.2. Phosphorus speciation
 2.3. Partitioning
 2.4. Phosphorus mass transport behavior
3. Results and discussion
 3.1. Hydrologic characterization of the monitored rainfall-runoff events
 3.2. Physically based differentiation of P transport
 3.3. Phosphorus speciation
 3.4. Effect of pH, alkalinity, and phosphorus partitioning on speciation
4. Conclusions
Acknowledgments
References


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