Curb-inlet storm drain systems for filtering trash and hydrocarbons

DETAILED DESCRIPTION The system includes the use of a quantity of appropriately formed fragments 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 materials can also absorb a variety of chemicals pollutants, such as benzene, carbon disulfide, and various chlorinated hydrocarbons.
The inventive system is designed to collect trash and oil or other pollutants spilled and flowing into a fluid receptacle such as curb-inlet 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.
A grate (not shown) of vertical slats or bars may be placed in the gap 106 in the curb (not shown) connecting sidewalk 102 and the gutter of street 104.
In the inventive system shown in FIG.
1, a flow consisting of water, pollutants, and trash (less larger trash items screened by the optional grate) enters storm drain 100 and falls into hopper 110.
Basket 120 screens trash remaining in the flow.
As trash accumulates in basket 120, the trash items thereby collected act as a secondary screen for new items in the mixed flow.
Basket 120 is formed, in one embodiment, of non-corrosive expanded metal (steel) with diamond-shaped holes approximately 0.
5.
times.
1.
0 mm.
in size.
Basket 120 is secured, such as by welding, to front lip 112 and back lip 114 of hopper 110.
A multitude of fragments 130, of a type discussed below, are held between the outside of basket 120 and the inside of hopper 110.
The fragments 130 are irregularly shaped, and not closely packed, allowing the liquid runoff to flow through hopper 110 at a high rate relative to cellulose or other known systems.
The fragments 130 are hydrophobic but absorb and hold oil and chemical pollutants, as explained in more detail below, and thereby extract those undesired materials from the storm flow