Settling velocity of particulate pollutants from combined sewer wet weather discharges.
Settling velocities of TSS and of particulate pollutants (COP, PDCO, PTKN, PCu, PPb, PZn, PPAH) measured on a wide range of wet weather flow (WWF) samples collected at different levels of the Parisian combined sewer system are reported. The recorded V30 (0.01 to 0.1 mm s(-1)) and V50 (0.09 to 0.6 mm s(-1)) values exceed by a factor 10 those of dry weather sewage and also exceed the values measured for pavement runoff. These values lie however often below the 0.28 mm s(-1) reference value considered in France for the design of WWF settling facilities. A decrease in settleability is observed between a small upstream catchment and larger scaled downstream catchments. The settling behaviour of particulate pollutants varies depending on the considered parameter and can differ significantly from the TSS behaviour, due to a non homogeneous distribution of micropolluants over the different classes of particles. PZn and PTKN appear far less settleable than TSS, whereas PPAH show higher settleability.
Gromaire
M C
MC
Université Paris-Est, Cereve, UMR-MA102-AgroParisTech, Marne-la-Vallée, France. gromaire@cereve.enpc.fr
Kafi-Benyahia
M
M
Gasperi
J
J
Saad
M
M
Moilleron
R
R
Chebbo
G
G
D002244:Carbon / Q000032:analysis; D004323:Drainage, Sanitary; D008670:Metals / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D011891:Rain; D014865:Waste Disposal, Fluid; D014873:Water Pollutants / Q000737:chemistry*
D008670:Metals; D009930:Organic Chemicals; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D014873:Water Pollutants; D002244:Carbon; D009584:Nitrogen