Claims
- 1. A method for retrofitting existing waste water treatment facilities having at least one existing basin comprising:
installing generally vertical partitions at spaced locations in said at least one existing basin in order to divide said at least one existing basin into a plurality of treatment stage regions; installing at least one air lift in each of said plurality of treatment stage regions; loading each treatment stage regions with a quantity of floatable porous particles; supplying waste water to at least one of said plurality of treatment stage regions and allowing said waste water, but generally not said particles, to flow from at least one of said plurality of treatment stage regions to at least another of said plurality of treatment stage regions; and operating said at least one air lift in each of said plurality of treatment stage regions to provide aerobic waste water flow therein in operative engagement with said floatable porous particles.
- 2. A method according to claim 1 and wherein at least some of said vertical partitions are spaced from a bottom of said at least one basin in order to allow said waste water to flow thereunder between adjacent ones of said plurality of treatment stage regions.
- 3. A method according to claim 1 and wherein said at least one air lift comprises at least one air diffuser disposed underlying a peripheral enclosure which defines a column of water which is lifted by air diffusing upwardly from said at least one air diffuser therethrough.
- 4. A method according to claim 3 and wherein said peripheral enclosure comprises a cylindrical enclosure.
- 5. A method according to claim 3 and wherein said peripheral enclosure comprises a plurality of spaced generally vertical walls which extend between walls of the basin and are separated from the bottom of the basin.
- 6. A method according to claim 1 and wherein said floatable particles comprise porous plastic particles having a density lower than that of pure water.
- 7. A method according to claim 6 and wherein said particles have a specific gravity between 0.65 and 0.95.
- 8. A method according to claim 6 and wherein said particles have an irregular shape, whose largest dimension is generally between 4-10 mm.
- 9. A method according to claim 6 and wherein said particles have a total porosity exceeding 50 %.
- 10. A method according to claim 6 and wherein said particles have a mean pore diameter of pores, whose diameter exceeds 10 microns, of about 20 microns.
- 11. A method according to claim 1 and wherein said generally vertical partitions divide said basin into between 4 and 12 process stages.
- 12. A method according to claim 1 and wherein said at least one air lift comprises a series of air lifts arranged in said multiple process stages.
- 13. A method according to claim 12 and wherein said series of air lifts includes at each process stage an initial air lift assembly and at least one intermediate air lift assembly.
- 14. A method according to claim 13 and wherein said initial air lift assembly includes a upstream partition which extends downwardly from a top location above a water level in said basin to a bottom location spaced from the bottom of said basin.
- 15. A method according to claim 14 and wherein said upstream partition extends fully from side to side of said basin.
- 16. A method according to claim 14 and wherein said upstream partition is attached to a deflector which extends in a downstream direction from said upstream partition at said water level.
- 17. A method according to claim 13 and wherein said initial air lift assembly also includes a downstream partition which extends fully from side to side of said basin but does not extend up to said water level.
- 18. A method according to claim 13 and wherein said intermediate air lift assembly includes an upstream partition which extends downwardly from a top location below said water level in basin to a bottom location spaced from said bottom of said basin.
- 19. A method according to claim 1 and wherein said vertical partitions each extend fully from side to side of said basin.
- 20. A method according to claim 13 and wherein said at least one intermediate air lift assembly comprises an upstream partition separated from a deflector plate which extends in a downstream direction from said upstream partition at said water level.
- 21. A method according to claim 20 and wherein said at least one intermediate air lift assembly also includes a downstream partition which does not extend up to said water level or as close to said bottom of said basin as does said upstream partition.
- 22. A method according to claim 1 and wherein said installing also includes installing a final air lift assembly including an upstream partition which extends downwardly from a top location below said water level in said basin to a bottom location spaced from said bottom of said basin and extends fully from side to side of said basin.
- 23. A method according to claim 22 and wherein said final air lift assembly also includes a downstream partition which also extends fully from side to side of said basin and extends to a top location above said water level and closer to said bottom than does said upstream partition.
- 24. A method according to claim 23 and wherein said downstream partition is attached to a deflector plate which extends in an upstream direction from downstream partition at a location at said water level.
- 25. A method according to claim 1 and wherein:
said at least one air lift comprises a plurality of air lift assemblies each including upstream and downstream partitions: a first plurality of air diffusers are disposed at said bottom of said basin intermediate upstream and downstream partitions of said plurality of air lift assemblies; and a second plurality of air diffusers, lesser in number than said first plurality of air diffusers, are disposed at said bottom of said basin intermediate said plurality of air lift assemblies.
- 26. A method according to claim 25 and wherein said first plurality of air diffusers intermediate said upstream and downstream partitions of each air lift assembly causes water to flow upward between said upstream and downstream partitions of each air lift assembly.
- 27. A method according to claim 26 and wherein said second plurality of air diffusers intermediate said plurality of air lift assemblies allows water to flow downward.
- 28. A method according to claim 1 and wherein said loading comprises loading 10-40 percent of said volume of said basin with particles in absence of water flow.
- 29. A method according to claim 1 and wherein said supplying comprises providing a continuous flow of water from said upstream side of said basin from said waste water inlet to said treated water outlet.
- 30. A method according to claim 29 and wherein said flow is an undulating flow and includes passage under upstream partitions which is of relatively low volume and generally does not carry floating particles into said at least one air lift, thereby constraining said particles to reside outside of and between said at least one air lift.
- 31. A method according to claim 25 and also comprising controlling the flow velocity of water by controlling operation of said first and second pluralities of air diffusers.
- 32. A method according to claim 1 and wherein said at least one air lift includes an adjustable angle deflector.
- 33. A method according to claim 1 and wherein said at least one air lift includes an integral curved downstream partition and deflector.
- 34. A method according to claim 1 and also comprising installing a denitrification unit in at least one of said plurality of treatment stage regions.
- 35. A method according to claim 34 and wherein said denitrification unit comprises a plurality of axial pumps which provide lift generally without an air flow, thereby to provide an anoxic de-nitrification process.
- 36. A method according to claim 1 and wherein said at least one air lift comprises an array of air lifts and wherein said array of air lifts comprises a multiplicity of cylindrical air lifts arranged in said plurality of treatment stage regions and separated by said vertical partitions which extend from a bottom location which is spaced from a bottom of said basin by a first vertical separation.
- 37. A method according to 36 and wherein said cylindrical air lifts each comprise:
a hollow shaft which extends from a bottom location spaced from a bottom of said basin by a second vertical separation which exceeds said first separation; a deflector which is disposed in spaced relationship over each hollow shaft and is disposed at said water level; and at least one air diffuser which is disposed underlying each hollow shaft to provide an air lift therethrough, thereby causing water to flow into said hollow shafts and upwardly through said hollow shafts, said deflectors causing said water exiting said tops of said hollow shafts to move sideways and downwardly.
- 38. A method according to claim 37 and also comprising:
a plurality of air diffusers disposed immediately upstream of each said vertical partition for providing control of particle movement and prevention of particle migration.
- 39. A method according to claim 1 and wherein said operating produces fluidization of said particles.
- 40. A method according to claim 1 and wherein said operating is operative, when said particles become heavily coated with biomass to cause said particles sometimes to enter said at least one air lift and to be sloughed of some of said biomass as they are propelled upwards by said action of said at least one air lift.
- 41. A method for waste water treatment employing at least one basin comprising:
installing generally vertical partitions at spaced locations in said at least one basin in order to divide said at least one basin into a plurality of treatment stage regions; installing at least one air lift in each of said plurality of treatment stage regions; loading each treatment stage regions with a quantity of floatable porous particles; supplying waste water to at least one of said plurality of treatment stage regions and allowing said waste water, but generally not said particles, to flow from at least one of said plurality of treatment stage regions to at least another of said plurality of treatment stage regions; and operating said at least one air lift in each of said plurality of treatment stage regions to provide aerobic waste water flow therein in operative engagement with said floatable porous particles.
- 42. A method according to claim 41 and wherein at least some of said vertical partitions are spaced from a bottom of said at least one basin in order to allow said waste water to flow thereunder between adjacent ones of said plurality of treatment stage regions.
- 43. A method according to claim 41 and wherein said at least one air lift comprises at least one air diffuser disposed underlying a peripheral enclosure which defines a column of water which is lifted by air diffusing upwardly from said at least one air diffuser therethrough.
- 44. A method according to claim 43 and wherein said peripheral enclosure comprises a cylindrical enclosure.
- 45. A method according to claim 43 and wherein said peripheral enclosure comprises a plurality of spaced generally vertical walls which extend between walls of the basin and are separated from the bottom of the basin.
- 46. A method according to claim 41 and wherein said floatable particles comprise porous plastic particles having a density lower than that of pure water.
- 47. A method according to claim 46 and wherein said particles have a specific gravity between 0.65 and 0.95.
- 48. A method according to claim 46 and wherein said particles have an irregular shape, whose largest dimension is generally between 4-10 mm.
- 49. A method according to claim 46 and wherein said particles have a total porosity exceeding 50 %.
- 50. A method according to claim 46 and wherein said particles have a mean pore diameter of pores, whose diameter exceeds 10 microns, of about 20 microns.
- 51. A method according to claim 41 and wherein said generally vertical partitions divide said basin into between 4 and 12 process stages.
- 52. A method according to claim 41 and wherein said at least one air lift comprises a series of air lifts arranged in said multiple process stages.
- 53. A method according to claim 52 and wherein said series of air lifts includes at each process stage an initial air lift assembly and at least one intermediate air lift assembly.
- 54. A method according to claim 53 and wherein said initial air lift assembly includes a upstream partition which extends downwardly from a top location above a water level in said basin to a bottom location spaced from the bottom of said basin.
- 55. A method according to claim 54 and wherein said upstream partition extends fully from side to side of said basin.
- 56. A method according to claim 54 and wherein said upstream partition is attached to a deflector which extends in a downstream direction from said upstream partition at said water level.
- 57. A method according to claim 53 and wherein said initial air lift assembly also includes a downstream partition which extends fully from side to side of said basin but does not extend up to said water level.
- 58. A method according to claim 53 and wherein said intermediate air lift assembly includes an upstream partition which extends downwardly from a top location below said water level in basin to a bottom location spaced from said bottom of said basin.
- 59. A method according to claim 41 and wherein said vertical partitions each extend fully from side to side of said basin.
- 60. A method according to claim 53 and wherein said at least one intermediate air lift assembly comprises an upstream partition separated from a deflector plate which extends in a downstream direction from said upstream partition at said water level.
- 61. A method according to claim 60 and wherein said at least one intermediate air lift assembly also includes a downstream partition which does not extend up to said water level or as close to said bottom of said basin as does said upstream partition.
- 62. A method according to claim 41 and wherein said installing also includes installing a final air lift assembly including an upstream partition which extends downwardly from a top location below said water level in said basin to a bottom location spaced from said bottom of said basin and extends fully from side to side of said basin.
- 63. A method according to claim 62 and wherein said final air lift assembly also includes a downstream partition which also extends filly from side to side of said basin and extends to a top location above said water level and closer to said bottom than does said upstream partition.
- 64. A method according to claim 63 and wherein said downstream partition is attached to a deflector plate which extends in an upstream direction from downstream partition at a location at said water level.
- 65. A method according to claim 41 and wherein:
said at least one air lift comprises a plurality of air lift assemblies each including upstream and downstream partitions: a first plurality of air diffusers are disposed at said bottom of said basin intermediate upstream and downstream partitions of said plurality of air lift assemblies; and a second plurality of air diffusers, lesser in number than said first plurality of air diffusers, are disposed at said bottom of said basin intermediate said plurality of air lift assemblies.
- 66. A method according to claim 65 and wherein said first plurality of air diffusers intermediate said upstream and downstream partitions of each air lift assembly causes water to flow upward between said upstream and downstream partitions of each air lift assembly.
- 67. A method according to claim 66 and wherein said second plurality of air diffusers intermediate said plurality of air lift assemblies allows water to flow downward.
- 68. A method according to claim 41 and wherein said loading comprises loading 10-40 percent of said volume of said basin with particles in absence of water flow.
- 69. A method according to claim 41 and wherein said supplying comprises providing a continuous flow of water from said upstream side of said basin from said waste water inlet to said treated water outlet.
- 70. A method according to claim 69 and wherein said flow is an undulating flow and includes passage under upstream partitions which is of relatively low volume and generally does not carry floating particles into said at least one air lift, thereby constraining said particles to reside outside of and between said at least one air lift.
- 71. A method according to claim 65 and also comprising controlling the flow velocity of water by controlling operation of said first and second pluralities of air diffusers.
- 72. A method according to claim 41 and wherein said at least one air lift includes an adjustable angle deflector.
- 73. A method according to claim 41 and wherein said at least one air lift includes an integral curved downstream partition and deflector.
- 74. A method according to claim 41 and also comprising installing a denitrification unit in at least one of said plurality of treatment stage regions.
- 75. A method according to claim 74 and wherein said denitrification unit comprises a plurality of axial pumps which provide lift generally without an air flow, thereby to provide an anoxic de-nitrification process.
- 76. A method according to claim 41 and wherein said at least one air lift comprises an array of air lifts and wherein said array of air lifts comprises a multiplicity of cylindrical air lifts arranged in said plurality of treatment stage regions and separated by said vertical partitions which extend from a bottom location which is spaced from a bottom of said basin by a first vertical separation.
- 77. A method according to 76 and wherein said cylindrical air lifts each comprise:
a hollow shaft which extends from a bottom location spaced from a bottom of said basin by a second vertical separation which exceeds said first separation; a deflector which is disposed in spaced relationship over each hollow shaft and is disposed at said water level; and at least one air diffuser which is disposed underlying each hollow shaft to provide an air lift therethrough, thereby causing water to flow into said hollow shafts and upwardly through said hollow shafts, said deflectors causing said water exiting said tops of said hollow shafts to move sideways and downwardly.
- 78. A method according to claim 77 and also comprising:
a plurality of air diffusers disposed immediately upstream of each said vertical partition for providing control of particle movement and prevention of particle migration.
- 79. A method according to claim 41 and wherein said operating produces fluidization of said particles.
- 80. A method according to claim 41 and wherein said operating is operative, when said particles become heavily coated with biomass to cause said particles sometimes to enter said at least one air lift and to be sloughed of some of said biomass as they are propelled upwards by said action of said at least one air lift.
- 81. Retrofitted waste water treatment apparatus comprising:
at least one existing basin; generally vertical partitions located at spaced locations in said at least one existing basin in order to divide said at least one existing basin into a plurality of treatment stage regions; at least one air lift located in each of said plurality of treatment stage regions; and a quantity of floatable porous particles loaded into each of said plurality of treatment stage regions, whereby supplying waste water to at least one of said plurality of treatment stage regions and allowing said waste water, but generally not said particles, to flow from at least one of said plurality of treatment stage regions to at least another of said plurality of treatment stage regions and operating said at least one air lift in each of said plurality of treatment stage regions provides aerobic waste water flow therein in operative engagement with said floatable porous particles.
- 82. Apparatus according to claim 81 and wherein at least some of said vertical partitions are spaced from a bottom of said at least one basin in order to allow said waste water to flow thereunder between adjacent ones of said plurality of treatment stage regions.
- 83. Apparatus according to claim 81 and wherein said at least one air lift comprises at least one air diffuser disposed underlying a peripheral enclosure which defines a column of water which is lifted by air diffusing upwardly from said at least one air diffuser therethrough.
- 84. Apparatus according to claim 83 and wherein said peripheral enclosure comprises a cylindrical enclosure.
- 85. Apparatus according to claim 83 and wherein said peripheral enclosure comprises a plurality of spaced generally vertical walls which extend between walls of the basin and are separated from the bottom of the basin.
- 86. Apparatus according to claim 81 and wherein said floatable particles comprise porous plastic particles having a density lower than that of pure water.
- 87. Apparatus according to claim 86 and wherein said particles have a specific gravity between 0.65 and 0.95.
- 88. Apparatus according to claim 86 and wherein said particles have an irregular shape, whose largest dimension is generally between 4-10 mm.
- 89. Apparatus according to claim 86 and wherein said particles have a total porosity exceeding 50 %.
- 90. Apparatus according to claim 86 and wherein said particles have a mean pore diameter of pores, whose diameter exceeds 10 microns, of about 20 microns.
- 91. Apparatus according to claim 81 and wherein said generally vertical partitions divide said basin into between 4 and 12 process stages.
- 92. Apparatus according to claim 81 and wherein said at least one air lift comprises a series of air lifts arranged in said multiple process stages.
- 93. Apparatus according to claim 92 and wherein said series of air lifts includes at each process stage an initial air lift assembly and at least one intermediate air lift assembly.
- 94. Apparatus according to claim 93 and wherein said initial air lift assembly includes a upstream partition which extends downwardly from a top location above a water level in said basin to a bottom location spaced from the bottom of said basin.
- 95. Apparatus according to claim 94 and wherein said upstream partition extends fully from side to side of said basin.
- 96. Apparatus according to claim 94 and wherein said upstream partition is attached to a deflector which extends in a downstream direction from said upstream partition at said water level.
- 97. Apparatus according to claim 93 and wherein said initial air lift assembly also includes a downstream partition which extends fully from side to side of said basin but does not extend up to said water level.
- 98. Apparatus according to claim 93 and wherein said intermediate air lift assembly includes an upstream partition which extends downwardly from a top location below said water level in basin to a bottom location spaced from said bottom of said basin.
- 99. Apparatus according to claim 81 and wherein said vertical partitions each extend fully from side to side of said basin.
- 100. Apparatus according to claim 93 and wherein said at least one intermediate air lift assembly comprises an upstream partition separated from a deflector plate which extends in a downstream direction from said upstream partition at said water level.
- 101. Apparatus according to claim 100 and wherein said at least one intermediate air lift assembly also includes a downstream partition which does not extend up to said water level or as close to said bottom of said basin as does said upstream partition.
- 102. Apparatus according to claim 81 and wherein said installing also includes installing a final air lift assembly including an upstream partition which extends downwardly from a top location below said water level in said basin to a bottom location spaced from said bottom of said basin and extends fully from side to side of said basin.
- 103. Apparatus according to claim 102 and wherein said final air lift assembly also includes a downstream partition which also extends fully from side to side of said basin and extends to a top location above said water level and closer to said bottom than does said upstream partition.
- 104. Apparatus according to claim 103 and wherein said downstream partition is attached to a deflector plate which extends in an upstream direction from downstream partition at a location at said water level.
- 105. Apparatus according to claim 81 and wherein:
said at least one air lift comprises a plurality of air lift assemblies each including upstream and downstream partitions: a first plurality of air diffusers are disposed at said bottom of said basin intermediate upstream and downstream partitions of said plurality of air lift assemblies; and a second plurality of air diffusers, lesser in number than said first plurality of air diffusers, are disposed at said bottom of said basin intermediate said plurality of air lift assemblies.
- 106. Apparatus according to claim 105 and wherein said first plurality of air diffusers intermediate said upstream and downstream partitions of each air lift assembly causes water to flow upward between said upstream and downstream partitions of each air lift assembly.
- 107. Apparatus according to claim 106 and wherein said second plurality of air diffusers intermediate said plurality of air lift assemblies allows water to flow downward.
- 108. Apparatus according to claim 81 and where in said loading comprises loading 10-40 percent of said volume of said basin with particles in absence of water flow.
- 109. Apparatus according to claim 81 and wherein said s supplying comprises providing a continuous flow of water from said upstream side of said basin from said waste water inlet to said treated water outlet.
- 110. Apparatus according to claim 109 and wherein said flow is an undulating flow and includes passage under upstream partitions which is of relatively low volume and generally does not carry floating particles into said at least one air lift, thereby constraining said particles to reside outside of and between said at least one air lift.
- 111. Apparatus according to claim 105 and also comprising controlling the flow velocity of water by controlling operation of said first and second pluralities of air diffusers.
- 112. Apparatus according to claim 81 and wherein said at least one air lift includes an adjustable angle deflector.
- 113. Apparatus according to claim 81 and wherein said at least one air lift includes an integral curved downstream partition and deflector.
- 114. Apparatus according to claim 81 and also comprising installing a denitrification unit in at least one of said plurality of treatment stage regions.
- 115. Apparatus according to claim 93 and wherein said denitrification unit comprises a plurality of axial pumps which provide lift generally without an air flow, thereby to provide ananoxic de-nitrification process.
- 116. Apparatus according to claim 81 and wherein said at least one air lift comprises an array of air lifts and wherein said array of air lifts comprises a multiplicity of cylindrical air lifts arranged in said plurality of treatment stage regions and separated by said vertical partitions which extend from a bottom location which is spaced from a bottom of said basin by a first vertical separation.
- 117. Apparatus according to 116 and wherein said cylindrical air lifts each comprise:
a hollow shaft which extends from a bottom location spaced from a bottom of said basin by a second vertical separation which exceeds said first separation; a deflector which is disposed in spaced relationship over each hollow shaft and is disposed at said water level; and at least one air diffuser which is disposed underlying each hollow shaft to provide an air lift therethrough, thereby causing water to flow into said hollow shafts and upwardly through said hollow shafts, said deflectors causing said water exiting said tops of said hollow shafts to move sideways and downwardly.
- 118. Apparatus according to claim 117 and also comprising:
a plurality of air diffusers disposed immediately upstream of each said vertical partition for providing control of particle movement and prevention of particle migration.
- 119. Apparatus according to claim 81 and wherein said operating produces fluidization of said particles.
- 120. Apparatus according to claim 81 and wherein said operating is operative, when said particles become heavily coated with biomass to cause said particles sometimes to enter said at least one air lift and to be sloughed of some of said biomass as they are propelled upwards by said action of said at least one air lift.
- 121. Waste water treatment apparatus comprising:
at least one basin; generally vertical partitions located at spaced locations in said at least one basin in order to divide said at least one basin into a plurality of treatment stage regions; at least one air lift located in each of said plurality of treatment stage regions; and a quantity of floatable porous particles loaded into each of said plurality of treatment stage regions, whereby supplying waste water to at least one of said plurality of treatment stage regions and allowing said waste water, but generally not said particles, to flow from at least one of said plurality of treatment stage regions to at least another of said plurality of treatment stage regions and operating said at least one air lift in each of said plurality of treatment stage regions provides aerobic waste water flow therein in operative engagement with said floatable porous particles.
- 122. Apparatus according to claim 121 and wherein at least some of said vertical partitions are spaced from a bottom of said at least one basin in order to allow said waste water to flow thereunder between adjacent ones of said plurality of treatment stage regions.
- 123. Apparatus according to claim 121 and wherein said at least one air lift comprises at least one air diffuser disposed underlying a peripheral enclosure which defines a column of water which is lifted by air diffusing upwardly from said at least one air diffuser therethrough.
- 124. Apparatus according to claim 123 and wherein said peripheral enclosure comprises a cylindrical enclosure.
- 125. Apparatus according to claim 123 and wherein said peripheral enclosure comprises a plurality of spaced generally vertical walls which extend between walls of the basin and are separated from the bottom of the basin.
- 126. Apparatus according to claim 121 and wherein said floatable particles comprise porous plastic particles having a density lower than that of pure water.
- 127. Apparatus according to claim 126 and wherein said particles have a specific gravity between 0.65 and 0.95.
- 128. Apparatus according to claim 126 and wherein said particles have an irregular shape, whose largest dimension is generally between 4-10 mm.
- 129. Apparatus according to claim 126 and wherein said particles have a total porosity exceeding 50%.
- 130. Apparatus according to claim 126 and wherein said particles have a mean pore diameter of pores, whose diameter exceeds 10 microns, of about 20 microns.
- 131. Apparatus according to claim 121 and wherein said generally vertical partitions divide said basin into between 4 and 12 process stages.
- 132. Apparatus according to claim 121 and wherein said at least one air lift comprises a series of air lifts arranged in said multiple process stages.
- 133. Apparatus according to claim 132 and wherein said series of air lifts includes at each process stage an initial air lift assembly and at least one intermediate air lift assembly.
- 134. Apparatus according to claim 133 and wherein said initial air lift assembly includes a upstream partition which extends downwardly from a top location above a water level in said basin to a bottom location spaced from the bottom of said basin.
- 135. Apparatus according to claim 134 and wherein said upstream partition extends fully from side to side of said basin.
- 136. Apparatus according to claim 134 and wherein said upstream partition is attached to a deflector which extends in a downstream direction from said upstream partition at said water level.
- 137. Apparatus according to claim 133 and wherein said initial air lift assembly also includes a downstream partition which extends fully from side to side of said basin but does not extend up to said water level.
- 138. Apparatus according to claim 133 and wherein said intermediate air lift assembly includes an upstream partition which extends downwardly from a top location below said water level in basin to a bottom location spaced from said bottom of said basin.
- 139. Apparatus according to claim 121 and wherein said vertical partitions each extend fully from side to side of said basin.
- 140. Apparatus according to claim 133 and wherein said at least one intermediate air lift assembly comprises an upstream partition separated from a deflector plate which extends in a downstream direction from said upstream partition at said water level.
- 141. Apparatus according to claim 140 and wherein said at least one intermediate air lift assembly also includes a downstream partition which does not extend up to said water level or as close to said bottom of said basin as does said upstream partition.
- 142. Apparatus according to claim 121 and wherein said installing also includes installing a final air lift assembly including an upstream partition which extends downwardly from a top location below said water level in said basin to a bottom location spaced from said bottom of said basin and extends fully from side to side of said basin.
- 143. Apparatus according to claim 142 and wherein said final air lift assembly also includes a downstream partition which also extends fully from side to side of said basin and extends to a top location above said water level and closer to said bottom than does said upstream partition.
- 144. Apparatus according to claim 143 and wherein said downstream partition is attached to a deflector plate which extends in an upstream direction from downstream partition at a location at said water level.
- 145. Apparatus according to claim 121 and wherein:
said at least one air lift comprises a plurality of air lift assemblies each including upstream and downstream partitions: a first plurality of air diffusers are disposed at said bottom of said basin intermediate upstream and downstream partitions of said plurality of air lift assemblies; and a second plurality of air diffusers, lesser in number than said first plurality of air diffusers, are disposed at said bottom of said basin intermediate said plurality of air lift assemblies.
- 146. Apparatus according to claim 145 and wherein said first plurality of air diffusers intermediate said upstream and downstream partitions of each air lift assembly causes water to flow upward between said upstream and downstream partitions of each air lift assembly.
- 147. Apparatus according to claim 146 and wherein said second plurality of air diffusers intermediate said plurality of air lift assemblies allows water to flow downward.
- 148. Apparatus according to claim 121 and wherein said loading comprises loading 10-40 percent of said volume of said basin with particles in absence of water flow.
- 149. Apparatus according to claim 121 and wherein said supplying comprises providing a continuous flow of water from said upstream side of said basin from said waste water inlet to said treated water outlet.
- 150. Apparatus according to claim 149 and wherein said flow is an undulating flow and includes passage under upstream partitions which is of relatively low volume and generally does not carry floating particles into said at least one air lift, thereby constraining said particles to reside outside of and between said at least one air lift.
- 151. Apparatus according to claim 145 and also comprising controlling the flow velocity of water by controlling operation of said first and second pluralities of air diffusers.
- 152. Apparatus according to claim 121 and wherein said at least one air lift includes an adjustable angle deflector.
- 153. Apparatus according to claim 121 and wherein said at least one air lift includes an integral curved downstream partition and deflector.
- 154. Apparatus according to claim 121 and also comprising installing a denitrification unit in at least one of said plurality of treatment stage regions.
- 155. Apparatus according to claim 133 and wherein said denitrification unit comprises a plurality of axial pumps which provide lift generally without an air flow, thereby to provide an anoxic de-nitrification process.
- 156. Apparatus according to claim 121 and wherein said at least one air lift comprises an array of air lifts and wherein said array of air lifts comprises a multiplicity of cylindrical air lifts arranged in said plurality of treatment stage regions and separated by said vertical partitions which extend from a bottom location which is spaced from a bottom of said basin by a first vertical separation.
- 157. Apparatus according to 156 and wherein said cylindrical air lifts each comprise:
a hollow shaft which extends from a bottom location spaced from a bottom of said basin by a second vertical separation which exceeds said first separation; a deflector which is disposed in spaced relationship over each hollow shaft and is disposed at said water level; and at least one air diffuser which is disposed underlying each hollow shaft to provide an air lift therethrough, thereby causing water to flow into said hollow shafts and upwardly through said hollow shafts, said deflectors causing said water exiting said tops of said hollow shafts to move sideways and downwardly.
- 158. Apparatus according to claim 157 and also comprising:
a plurality of air diffusers disposed immediately upstream of each said vertical partition for providing control of particle movement and prevention of particle migration.
- 159. Apparatus according to claim 121 and wherein said operating produces fluidization of said particles.
- 160. Apparatus according to claim 121 and wherein said operating is operative, when said particles become heavily coated with biomass to cause said particles sometimes to enter said at least one air lift and to be sloughed of some of said biomass as they are propelled upwards by said action of said at least one air lift.
BACKGROUND OF THE INVENTION
[0001] The following patents and publications are believed to represent the current state of the art:
[0002] U.S. Pat. Nos. 3,133,017; 4,045,344; 4,137,171; 4,231,863; 4,256,573; 4,374,730; 4,394,268; 4,521,311; 4,454,038; 4,521,311; 4,566,971; 4,599,174; 4,810,377; 4,820,415; 4,839,053; 5,030,353; 5,200,081; 5,202,027; 5,554,289; 5,698,094; 6,036,863.
[0003] French Patent FR 2,707,183.