Method of constructing a filtering pavement surface
A sorptive-filtration system for removing at least one of negatively or positively charged ions, complexes or particulates from an aqueous stream. The system includes a) flow formed substantially from at least one of rainfall-runoff or snowmelt-runoff; b) a filter containment communicating with the runoff stream such that at least part of the stream passes through the filter containment; and c) a granular filter media disposed within the filter containment, the filter media having an amphoteric material applied thereto, wherein the amphoteric material comprises a metal selected from at least one of Fe, Al, Mn, or Si.
1. A method of constructing a roadway having a filtering shoulder material comprising the steps of:
a. placing pavement to form at least one driving lane;
b. placing a shoulder material adjacent to said driving lane such that rainwater runoff from said driving lane flows onto said shoulder material and percolates therethrough;
c. said shoulder material comprising a hydraulic conductivity of at least about 0.001 cm/sec and an amphoteric compound bonded thereto.
2. The method of constructing a roadway according to claim 1 , wherein said driving lane is substantially impervious to water such that rainfall runoff flows to said shoulder material.
3. The method of constructing a roadway according to claim 1 , wherein said placement of shoulder material comprises placing gravel having a said amphoteric compound coated thereon.
4. The method of constructing a roadway according to claim 3 , wherein said amphoteric compound is coated onto said gravel prior to said gravel being placed as said shoulder material.
5. The method of constructing a roadway according to claim 3 , wherein said gravel is placed as said shoulder material prior to a liquid containing said amphoteric compound being sprayed onto said gravel.
6. The method of constructing a roadway according to claim 3 , wherein said gravel is graded to have an average diameter of about 0.75 to about 1.0 inches and is placed at a depth of at least about four inches.
7. The method of constructing a roadway according to claim 1 , wherein placing said shoulder material comprises placing an alkaline cementitious pavement material.
8. The method of constructing a roadway according to claim 7 , wherein said driving lane is formed of a pavement material having a first compressive strength and said shoulder material is formed of a pavement material having a second and lesser compressive strength.
9. The method of constructing a roadway according to claim 7 , wherein prior to placing said cementitious pavement material, said amphoteric compound is combined with said cementitious pavement material as an admixture.
10. The method of constructing a roadway according to claim 9 , wherein a liquid containing said amphoteric compound is mixed with a paste forming said cementitious pavement material.
11. The method of constructing a roadway according to claim 7 , wherein after placing said cementitious pavement material, a liquid containing said amphoteric compound is sprayed onto said cementitious pavement material.
12. The method of constructing a roadway according to claim 7 , wherein said amphoteric compound comprises at least one oxide of iron, aluminum, manganese, or silicon.
13. The method of constructing a roadway according to claim 12 , wherein said amphoteric compound comprises either i) a combination of an iron oxide and a silicon oxide, or ii) a combination of an iron oxide and an aluminum oxide.
14. The method of constructing a roadway according to claim 7 , wherein said cementitious pavement material is formed from a slurry having a water to cement ratio ranging from about 0.3 to about 0.5.
15. The method of constructing a roadway according to claim 7 , wherein said cementitious material is placed as a continuous section.
16. The method of constructing a roadway according to claim 7 , wherein said cementitious material is placed as discrete blocks.
17. The method of constructing a roadway according to claim 7 , wherein mixing and/or placement conditions are controlled to provide said cementitious pavement material with a porosity of greater than about 0.1 upon drying.
18. A method of constructing a filtering pavement surface comprising the steps of:
a. placing a first pavement section having a first hydraulic conductivity;
b. placing a filter section adjacent to said first pavement section such that rainwater runoff from said first pavement section flows onto said filter section and percolates therethrough;
c. said filter section comprising (i) a second hydraulic conductivity, greater than said first hydraulic conductivity and at least about 0.001 cm/sec, and (ii) an amphoteric compound bonded thereto.
19. The method according to claim 18 , wherein placing said filter section comprises placing a porous cementitious pavement material.
20. The method of constructing a roadway according to claim 1 , wherein said hydraulic conductivity is between about 0.01 cm/sec and about 1 cm/sec.
21. The method of constructing a roadway according to claim 1 , wherein said cementitious pavement material comprises a hydraulic conductivity between about 0.01 cm/sec and about 1 cm/sec and a depth of at least about four inches.
22. The method according to claim 18 , wherein said placing said filter section comprises placing a granular material.
23. The method according to claim 22 , wherein said granular material is at least one from the group consisting of gravel, sand, wood chips, concrete rubble, natural aggregates, synthetic aggregates, polymeric compound media, lava rock, and granular activated carbon.
24. The method according to claim 18 , wherein said first pavement section is a roadway travel lane and said filter section is a shoulder for said travel lane.
25. The method according to claim 18 , wherein said first pavement section is a parking area and said filter section borders said parking area.
26. The method according to claim 18 , wherein (i) said first pavement section and said filter section are an alkaline cementitious type pavement materials and (ii) prior to placing said filter section, said amphoteric compound is combined with said cementitious pavement material as an admixture.
27. The method according to claim 26 , wherein an addition of water and/or said admixture comprises a water to cement ratio ranging from about 0.14 to about 0.5.
28. The method according to claim 26 , wherein said admixture comprises a substantially aqueous solution of at least one oxide of iron, manganese, aluminum, or silicon.
29. The method according to claim 25 , further comprising the step of forming said pavement surface with a length and a width, wherein the ratio between said length and said width is less than 20.
30. The method according to claim 18 , wherein prior to placing said filter section, said amphoteric compound in bonded to a material comprising said filter section.
31. The method according to claim 18 , wherein after placing said filter section, said amphoteric compound in bonded to a material comprising said filter section.