Storm drain systems for filtering trash and hydrocarbons

DETAILED DESCRIPTION The system includes the use of a quantity of appropriately formed bodies comprising copolymer-based materials that absorb and entrap crude or refined hydrocarbon products, including crude oil of any viscosity and gasoline or other refined fuels.
For purposes of this application, the term "oil" refers to any hydrocarbon material.
The inventive system is designed to collect trash and oil spilled and flowing into a fluid receptacle such as storm drain 100 shown in FIG.
1.
Storm drain 100 can be part of a municipal sewer or waste water system or any private collection system, such as at a gas station.
Frequently, as shown in FIG.
1, storm drain 100 is of a sort placed under sidewalk 102 at the margin of street or roadway 104.
Grate 106 is placed in a gap in a curb (not shown) connecting sidewalk 102 and the gutter of street 104.
Grate 106 may be fashioned of vertical slats, as shown, or alternatively vertical bars, or even may be omitted entirely in favor of a small opening to storm drain 100.
Preferably, grate 106 is removable by city workers for maintenance or retrofitting of the inventive system.
The horizontal spacing between slats or bars of grate 106, and the distance between the gutter of street 104 and sidewalk 102 into which grate 106 is placed, blocks some larger trash items, such as parts of blown automobile tires, tree branches, and larger drinking cups, from entering storm drain 100.
The remainder, indicated by the arrow labeled "flow" in FIG.
1, includes water and oil and trash carried along with the water.
(Some of slats of grate 106 are cut off in the foreground of FIG.
1, to show the flow more clearly.
) In the inventive system shown in FIG.
1, the resulting mixed flow enters storm drain 100 and passes over perforated plate 110, which is made of a non-corrosive material.
The perforations in plate 110 consist, in one embodiment, of staggered rows of elongated slits 112, perhaps 1-2 mm.
wide and about 5 cm.
long.
Arrangement alternative to slits 112 are possible, such as through the use of holes or wired grids