『Summary
Phosphorus (P) in rainfall-runoff partitions between dissolved
and particulate matter (PM) bound phases. This study investigates
the transport and partitioning of P to
PM fractions in runoff from a landscaped and biogenically-loaded
carpark in Gainesville, FL (GNV). Additionally, partitioning and
concentration results are compared to a similarly-sized concrete-paved
source area of a similar rainfall depth frequency distribution
in Baton Rouge, LA (BTR), where in contrast vehicular traffic
represents the main source of pollutants. Results illustrate that
concentrations of P fractions (dissolved, suspended, settleable
and sediment) for GNV are one to two orders of magnitude higher
than BTR. Despite these differences the dissolved fraction (fd) and partitioning coefficient (Kd)
distributions are similar, illustrating that P is predominantly
bound to PM fractions. Examining PM size fractions, specific capacity
for P (PSC) indicates that the P concentration order is suspended＞settleable＞
sediment for GNV, similarly to BTR. For GNV the dominant PM mass
fraction is sediment (＞75μm), while the mass of P is distributed
predominantly between sediment and suspended (＜25μm) fractions
since these PM mass fractions dominated the settleable one. With
respect to transport of PM and P fractions the predominance of
events for both areas is mass-limited first-flush, although each
fraction illustrated unique washoff parameters. However, while
transport is predominantly mass-limited, the transport of each
PM and P fraction is influenced by separate hydrologic parameters.
keywords: First-flush; hydrologic transport; Urban runoff; Phosphorus;
Particulate matter; Partitioning』
1. Introduction
2. Objectives
3. Methodology
3.1. Source area catchment, sampling and analysis methods
3.2. Partitioning
3.3. Washoff behaviour
3.4. Correlation of hydrologic and transport parameters
4. Results
4.1. Hydrologic characterization of the monitored rainfall-runoff
events
4.2. Event-based phosphorus loadings
4.3. Distribution of P fractions and PM specific capacities (PSC)
for P
4.4. Partitioning
4.5. Physically-based differentiation of P and PM transport
4.6. The significance of hydrologic parameters for source area
P and PM transport
5. Discussions
Acknowledgement
Appendix A. Supplementary material
References