Apparatus for the biological treatment of wastewater

Claim 2

In an apparatus for the treatment of wastewater, including a primary or secondary settling tank having inlet means for introducing raw wastewater, outlet means for removing treated wastewater and sludge removal means located in its lower portion for removing settled solids, the improvement comprising, a. a plurality of discs rotatably mounted in said settling tank b. said discs being supported on a plurality of parallel rotatable shafts disposed across said tank transverse to the flow of wastewater between said inlet and outlet means, c. said discs being partially submerged in said wastewater during operation, and d. driving means for rotating said shafts to impart a predetermined peripheral velocity to said discs e. said predetermined peripheral velocity being chosen to alternately expose the surface of said discs to wastewater in the tank and to the atmosphere at intervals sufficient to permit the growth of aerobic slimes on the surface of said discs.

Claim 3

In an apparatus for the treatment of wastewater, including a primary or secondary settling tank having inlet means for introducing raw wastewater, outlet means for removing treated wastewater and sludge removal means located in its lower portion for removing settled solids, the improvement comprising, a. a plurality of discs rotatably mounted in said settling tank b. said discs being supported on a plurality of parallel rotatable shafts disposed across said tank transverse to the flow of wastewater between said inlet and outlet means, c. said discs being partially submerged in said wastewater during operation, and d. driving means for rotating said shafts to impart a predetermined peripheral velocity to said discs e. said predetermined peripheral velocity being chosen to alternately expose the surface of said discs to wastewater in the tank and to the atmosphere at intervals sufficient to permit the growth of aerobic slimes on the surface of said discs.

Claim 4

In an apparatus for the treatment of wastewater, including a primary or secondary settling tank having inlet means for introducing raw wastewater, outlet means for removing treated wastewater and sludge removal means located in its lower portion for removing settled solids, the improvement comprising, a. a plurality of discs rotatably mounted in said settling tank b. said discs being supported on a plurality of parallel rotatable shafts disposed across said tank transverse to the flow of wastewater between said inlet and outlet means, c. said discs being partially submerged in said wastewater during operation, and d. driving means for rotating said shafts to impart a predetermined peripheral velocity to said discs e. said predetermined peripheral velocity being chosen to alternately expose the surface of said discs to wastewater in the tank and to the atmosphere at intervals sufficient to permit the growth of aerobic slimes on the surface of said discs.

Claim 5

The improved apparatus of claim 1 wherein a. the distance from the periphery of said discs to the bottom of said tank is greater than one half the diameter of said discs.

Claim 6

The improved apparatus of claim 2 wherein a. said discs are between about 3 and about 12 feet in diameter.

Claim 7

The improved apparatus of claim 1 wherein a. said driving means is adapted to periodically rotate said discs at a rate substantially greater than said predetermined rate.

Claim 8

The improved apparatus of claim 1 wherein a. said discs are spaced a predetermined distance apart on said shafts b. said predetermined distance is between about three-fourths inch and 2 inches.

Claim 9

A treatment tank for the continuous biological treatment of wastewater comprising, a. a tank struCture having a substantial length dimension b. inlet means for introducing wastewater into said rank structure. c. outlet means for removing wastewater from said tank structure, d. said inlet and outlet means being disposed at opposite ends of said length dimension of the treatment tank, e. a plurality of parallel rotatable shafts extending across said tank, transverse to said length dimension, f. a plurality of disc members having a predetermined diameter mounted on each of said shafts g. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, h. means for forceably rotating said shafts to impart a predetermined peripheral velocity to said disc members, i. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said disc members during operation, j. the distance from the periphery of said discs to the bottom of said tank being greater than one-half of said predetermined diameter, and k. sludge removal means disposed in the lower portion of said tank structure for removing settled solids from the bottom of said tank during operation.

Claim 10

A treatment tank for the continuous biological treatment of wastewater comprising, a. a tank struCture having a substantial length dimension b. inlet means for introducing wastewater into said rank structure. c. outlet means for removing wastewater from said tank structure, d. said inlet and outlet means being disposed at opposite ends of said length dimension of the treatment tank, e. a plurality of parallel rotatable shafts extending across said tank, transverse to said length dimension, f. a plurality of disc members having a predetermined diameter mounted on each of said shafts g. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, h. means for forceably rotating said shafts to impart a predetermined peripheral velocity to said disc members, i. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said disc members during operation, j. the distance from the periphery of said discs to the bottom of said tank being greater than one-half of said predetermined diameter, and k. sludge removal means disposed in the lower portion of said tank structure for removing settled solids from the bottom of said tank during operation.

Claim 11

The apparatus of claim 6 wherein said sludge removal means includes a sump located in the bottom of said tank approximately midway between said inlet and outlet means.

Claim 12

The apparatus of claim 7 wherein a. said plurality of discs are located between said sump and said outlet means.

Claim 13

The apparatus of claim 6 further including a. control means for maintaining a constant predetermined level of wastewater in said treatment tank, b. said control means including an overflow weir located in close proximity to said outlet means.

Claim 14

The apparatus of claim 6 wherein a. said plurality of discs mounted on each of said plurality of shafts forms a series of parallel banks of rotatable disc assemblies mounted in the upper portion of said treatment tank.

Claim 15

The apparatus of claim 10 further including a. baffling means disposed between the periphery of said discs and the bottom of said tank.

Claim 16

The apparatus of claim 11 wherein a. said baffling means includes a plurality of vertical baffles, each extending from below each of said disc assemblies to above the bottom of said treatment tank.

Claim 17

The apparatus of claim 10 further including a. a recirculation channel extending along the length dimension of said tank transverse to said parallel bank of rotatable disc assemblies, b. said channel being formed by absence of a plurality of discs from each of said parallel shafts c. said channel permitting the horizontal recirculation of said wastewater from said outlet means toward said inlet means.

Claim 18

The apparatus of claim 6 further including a. aeration means for supplying compressed air to said treatment tank.

Claim 19

A treatment tank for the continuous biological treatment of wastewater, comprising, a. a tank structure having a substantial length dimension, b. inlet means for introducing water into said tank structure, c. outlet means for removing wastewater from said tank structure, d. said inlet and outlet means being disposed at opposite ends of said length dimension of the treatment tank, e. plurality of parallel rotatable shafts extending across said tank, transverse to said length dimension, f. a plurality of disc members having a predetermined diameter mounted on each of said shafts, g. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, h. means for forceably rotating said shafts to impart a predetermined velocity to said disc members, i. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said disc members during operation, and j. sludge removal means disposed in the lower portion of said tank structure for removing settled sludge from the bottom of said tank during operation k. said sludge removal means includes a sump located in the bottom of said tank approximately midway between said inlet and outlet means, l. said plurality of discs being located between said sump and said outlet means.

Claim 20

A treatment tank for the continuous biological treatment of wastewater, comprising, a. a tank structure having a substantial length dimension, b. inlet means for introducing water into said tank structure, c. outlet means for removing wastewater from said tank structure, d. said inlet and outlet means being disposed at opposite ends of said length dimension of the treatment tank, e. plurality of parallel rotatable shafts extending across said tank, transverse to said length dimension, f. a plurality of disc members having a predetermined diameter mounted on each of said shafts, g. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, h. means for forceably rotating said shafts to impart a predetermined velocity to said disc members, i. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said disc members during operation, and j. sludge removal means disposed in the lower portion of said tank structure for removing settled sludge from the bottom of said tank during operation k. said sludge removal means includes a sump located in the bottom of said tank approximately midway between said inlet and outlet means, l. said plurality of discs being located between said sump and said outlet means.

Claim 21

The apparatus of claim 15, further including, a. control means for maintaining a constant predetermined level of wastewater in said treatment tank.

Claim 22

The apparatus of claim 16 wherein a. said control means includes an overflow weir in close proximity to said outlet means.

Claim 23

The apparatus of claim 16 wherein a. the submerged portion of said discs is not greater than one half of said predetermined level of wastewater in said tank.

Claim 24

Apparatus for the continuous biological treatment of wastewater comprising, a. a tank structure having inlet means for introducing wastewater and outlet means for removing treated wastewater, b. a plurality of parallel rotatable shafts extending across said tank, c. a plurality of disc members having a predetermined diameter mounted on each of said shafts, d. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, e. means for forceably rotating said shafts to impart a predetermined peripheral velocity to said disc members, f. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said discs during operation, and g. aeration means disposed in said treatment tank below said disc members, h. said aeration means discharging compressed air into said wastewater during operation of said tank.

Claim 25

Apparatus for the continuous biological treatment of wastewater comprising, a. a tank structure having inlet means for introducing wastewater and outlet means for removing treated wastewater, b. a plurality of parallel rotatable shafts extending across said tank, c. a plurality of disc members having a predetermined diameter mounted on each of said shafts, d. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, e. means for forceably rotating said shafts to impart a predetermined peripheral velocity to said disc members, f. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said discs during operation, and g. aeration means disposed in said treatment tank below said disc members, h. said aeration means discharging compressed air into said wastewater during operation of said tank.

Claim 26

The apparatus of claim 19 wherein a. said tank has a substantial longitudinal dimemsion defined by the distance between said inlet and outlet means and b. said shafts are disposed parallel to said longitudinal dimemsion of said tank.

Claim 27

The apparatus of claim 19 wherein, a. said predetermined peripheral velocity is between about 0.5 and about 3 feet per second.

Claim 28

The apparatus of claim 19 wherein, a. said aeration means is adapted to supply sufficient compressed air to retain slime sloughed off said disc members in suspension in said wastewater.

Claim 29

The apparatus of claim 22 further including, a. auxiliary means for settling said sloughed off slimes from said wastewater.

Claim 30

The apparatus of claim 23 wherein, a. said auxiliary means includes a settling tank, and b. means for supplying said wastewater to said settling tank from said tank structure.

Claim 31

Apparatus for the continuous biological treatment of wastewater comprising, a. a tank structure having a substantial length dimension, b. inlet means for introducing wastewater into said tank structure, c. outlet means for removing wastewater from said tank structure, d. said inlet and outlet means being disposed at opposite ends of said length dimemsion of the treatment tank, e. a plurality of parallel rotatable shafts extending across said tank, transverse to said length dimension, f. a plurality of disc members having a predetermined diameter mounted on each of said shafts, g. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, h. said plurality of disc members mounted on each of said parallel shafts forming a series of parallel banks of rotatable disc assemblies in the upper portion of said tank structure, i. means for forceably rotating said shafts to impart a predetermined peripheral velocity to said disc members, j. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said disc members duriNg operation, k. the distance from the periphery of said discs to the bottom of said tank being greater than one-half of said predetermined diameter, l. level control means for maintaining a constant predetermined level of wastewater in said tank structure and, m. speed control means for varying said peripheral velocity of said disc members, in response to variations in the quantity of wastewater entering said tank structure through said inlet means.

Claim 32

Apparatus for the continuous biological treatment of wastewater comprising, a. a tank structure having a substantial length dimension, b. inlet means for introducing wastewater into said tank structure, c. outlet means for removing wastewater from said tank structure, d. said inlet and outlet means being disposed at opposite ends of said length dimemsion of the treatment tank, e. a plurality of parallel rotatable shafts extending across said tank, transverse to said length dimension, f. a plurality of disc members having a predetermined diameter mounted on each of said shafts, g. said disc members being partially submerged in said wastewater during operation of said tank to more than one-third and less than two-thirds of said predetermined diameter, h. said plurality of disc members mounted on each of said parallel shafts forming a series of parallel banks of rotatable disc assemblies in the upper portion of said tank structure, i. means for forceably rotating said shafts to impart a predetermined peripheral velocity to said disc members, j. said predetermined peripheral velocity being suitable for the growth of aerobic biological slimes on the surface of said disc members duriNg operation, k. the distance from the periphery of said discs to the bottom of said tank being greater than one-half of said predetermined diameter, l. level control means for maintaining a constant predetermined level of wastewater in said tank structure and, m. speed control means for varying said peripheral velocity of said disc members, in response to variations in the quantity of wastewater entering said tank structure through said inlet means.

Claim 33

The apparatus of claim 25 wherein a. said level control means includes an overflow weir located in close proximity to said outlet means.

Claim 34

The apparatus of claim 26 further including, a. baffling means extending from below the periphery of said parallel banks of assemblies to above the bottom of said tank structure, b. said baffling means separating the portion of said tank structure between the periphery of said disc assemblies and the bottom of said tank structure into a series of individual settling zones.

Claim 35

The apparatus of claim 27 wherein, a. said baffling means includes a series of vertically disposed baffles below said disc assemblies.

Claim 36

The apparatus of claim 27 wherein, a. said baffling means includes a series of vertically inclined baffles.