Abstract:
A self-cleansing media and systems incorporating the same, for a rotating biological contactor, are described. The media includes a disk having cones extending perpendicularly from the surface thereof. Two or more disks lock together, axially about a rotating central shaft, by connecting cones spaced throughout the disk surface having a socket at their base to receive the top of the corresponding connecting cone on the adjacent disk. The cones, by virtue of their length, space the disks a desired distance. The disks include disk segments that can link to one another along either straight and/or curved portions thereof. The geometry of the media provides free passage of the air and water during each revolution, and while the base disk slices through the air and water, the projecting cones or cylinders enter the air and water perpendicular to the direction of rotation and are washed and cleansed during each rotation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present invention claims priority to U.S. Provisional Patent Application Ser. No. 60/525,642, filed Nov. 26, 2003, the entire specification of which is expressly incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to rotating biological contactors (“RBC&#39;s”) used in the field of wastewater treatment, and more particularly to the use of self-cleansing media, and systems incorporating the same, used in conjunction with RBC&#39;s. 
     BACKGROUND OF THE INVENTION 
     An RBC is typically comprised of a rotating shaft to which is attached a bank, or multiple banks, of media that are then in turn rotated by the shaft. A plurality of parallel support shafts is typically employed to aid in the support of the media. The media is typically located such that about 40 percent of the media is, at any given time, immersed in the wastewater to be cleaned. As the media rotates slowly into and out of the wastewater, microorganisms attach themselves to the media, forming a biomass, and consuming contaminates from the wastewater. As the media rotates into the air above the wastewater tank, the microorganisms biodegrade these contaminates, e.g., into carbon dioxide and water. 
     Examples of technology related to the treatment of wastewater and other substances can be found with reference to the following U.S. patents listed in the Table, below, the entire disclosures of which are expressly incorporated herein by reference: 
     
       
         
               
               
               
             
           
               
                 TABLE 
               
               
                   
               
               
                 U.S. Pat. No. 
                 Inventor(s) 
                 Title 
               
               
                   
               
             
             
               
                 1,811,181 
                 Maltby 
                 Process and Apparatus for 
               
               
                   
                   
                 Treating Sewage or Other 
               
               
                   
                   
                 Organic Matters 
               
               
                 1,947,777 
                 Huff et al. 
                 Filling Unit 
               
               
                 3,335,081 
                 El-Naggar 
                 Method of Treatment of 
               
               
                   
                   
                 Sewage by Bio-Oxidation 
               
               
                   
                   
                 and Apparatus Therefor 
               
               
                 3,484,836 
                 Welch 
                 Rotating Biological 
               
               
                   
                   
                 Contactor in Sewer 
               
               
                 3,630,366 
                 Joost 
                 Rotating Biological Waste 
               
               
                   
                   
                 Treatment System 
               
               
                 3,645,510 
                 Klugman 
                 Grid Member and Wall 
               
               
                   
                   
                 Formed Therefrom 
               
               
                 3,704,783 
                 Antoine 
                 Apparatus for Treating 
               
               
                   
                   
                 Sewage 
               
               
                 3,915,854 
                 Torpey 
                 Wastewater Treatment 
               
               
                 4,115,268 
                 Thissen 
                 Waste Water Treatment 
               
               
                   
                   
                 Rotor 
               
               
                 4,137,172 
                 Sako et al. 
                 Rotating Biological 
               
               
                   
                   
                 Contactor 
               
               
                 4,275,019 
                 Bednarski 
                 A Modular Heaping-Type 
               
               
                   
                   
                 Packing Element 
               
               
                 4,345,997 
                 McConnell, Jr. et al. 
                 Media 
               
               
                 4,431,537 
                 Hirota 
                 Revolving Contactors for 
               
               
                   
                   
                 the Biological Treatment of 
               
               
                   
                   
                 Waste Water 
               
               
                 4,444,658 
                 Hankes et al. 
                 Rotating Biological 
               
               
                   
                   
                 Contactor Apparatus 
               
               
                 4,537,678 
                 Thissen 
                 Rotary Biological Contactor 
               
               
                 4,549,962 
                 Koelsch 
                 Rotating Biological 
               
               
                   
                   
                 Contactor 
               
               
                 4,724,593 
                 Lang 
                 Method and Blank for the 
               
               
                   
                   
                 Manufacture of High 
               
               
                   
                   
                 Efficiency Open Volumed 
               
               
                   
                   
                 Packing Bodies 
               
               
                 4,737,278 
                 Miller 
                 Miniturized Modular 
               
               
                   
                   
                 Rotating Biological 
               
               
                   
                   
                 Contactor System 
               
               
                 5,407,578 
                 Nathwani 
                 Waste Water Treatment 
               
               
                   
                   
                 Process 
               
               
                 5,419,831 
                 Fuerst et al. 
                 Rotating Biological 
               
               
                   
                   
                 Aquarium Filter System 
               
               
                 5,423,978 
                 Snyder et al. 
                 Rotating Biologic Aquarium 
               
               
                   
                   
                 Filter System 
               
               
                 5,425,874 
                 Gass 
                 Rotating Contactor 
               
               
                   
                   
                 Including Cross Flow Media 
               
               
                   
                   
                 for the Biological Treatment 
               
               
                   
                   
                 of Waste Water 
               
               
                 5,458,817 
                 Lang 
                 Folding Packing and 
               
               
                   
                   
                 Method of Manufacture 
               
               
                 5,498,376 
                 St. Louis et al. 
                 Packing 
               
               
                 5,637,263 
                 Lang et al. 
                 Multifold Packing and 
               
               
                   
                   
                 Method of Forming 
               
               
                 5,679,253 
                 Fuerst et al. 
                 Rotating Biological 
               
               
                   
                   
                 Aquarium Filter System 
               
               
                 5,714,097 
                 St. Louis et al. 
                 Packing 
               
               
                 5,851,636 
                 Lang et al. 
                 Ceramic Packing With 
               
               
                   
                   
                 Channels for Thermal and 
               
               
                   
                   
                 Catalytic Beds 
               
               
                 5,853,591 
                 Snyder et al. 
                 Rotating Biological 
               
               
                   
                   
                 Aquarium Filter System 
               
               
                 6,071,593 
                 Lang et al. 
                 Ceramic Packing With 
               
               
                   
                   
                 Channels for Thermal and 
               
               
                   
                   
                 Catalytic Beds 
               
               
                 6,241,222 
                 Lang 
                 Stacked Packing With 
               
               
                   
                   
                 Spacing Features 
               
               
                 6,403,366 
                 Kim 
                 Method and Apparatus for 
               
               
                   
                   
                 Treating Volatile Organic 
               
               
                   
                   
                 Compounds, Odors, and 
               
               
                   
                   
                 Biodegradable in Air 
               
               
                   
                   
                 Emissions 
               
               
                 6,540,920 
                 Bounds et al. 
                 Wastewater Treatment 
               
               
                   
                   
                 System Utilizing Textile 
               
               
                   
                   
                 Filter Media 
               
               
                 6,783,669 
                 Okagawa et al. 
                 Rotating Disk Type Sewage 
               
               
                   
                   
                 Treatment Device 
               
               
                   
               
             
          
         
       
     
     The microorganisms in typical wastewater normally form a biomass on the media that is about 0.03 inches thick. When the system becomes overloaded, the biomass will typically grow to a thickness of about 0.15 inches. When this occurs, the microorganisms that were the first to attach to the media die because no food or oxygen can get to them. When this occurs over a large enough area, the biomass detaches itself from the media and sloughs off. 
     Conventional media is typically comprised of planar surfaces that are either flat or folded and are either made of a mesh or a solid sheet. Both the flat and the folded types of media are spaced to provide a path that allows the sloughed biomass (i.e., biomass that has become detached from the media) to be washed out of the media. This is needed to prevent plugging of the system which would reduce the media surface area exposed to contaminates in the wastewater and thus reduce the capacity of the system. 
     The mesh media, which by its nature must be flat, is also typically very flimsy. Because the mesh is a single flat disk, typically spaced from one another, in order to allow the sloughed biomass to be washed out of the media, the area exposed is typically limited to only about 32 square feet per cubic foot. Also, because the mesh is flimsy, the adjacent disks must be separated by many spacers or one disk will flop against the adjacent disk, reducing the surface area exposed. 
     Therefore, there exists a need for new and improved media, and systems incorporating the same, for use in conjunction with rotating biological contactors and the like. 
     SUMMARY OF THE INVENTION 
     In accordance with the general teachings of the present invention, new and improved media, and systems incorporating the same, for use in conjunction with rotating biological contactors and the like, are provided. 
     The present invention allows for a significant increase in the surface area of media exposed to the wastewater, as compared to conventional media systems. Without being bound to a particular theory of the operation of the present invention, it is believed that the present invention provides a surface area exposure in the range of about 95 to about 110 square feet per cubic feet of media in the low density first stage. 
     In accordance with a first embodiment of the present invention, a rotating biological contactor system is provided, comprising: (1) a substantially circular first media disk, comprising: (a) a first media segment having first and second major faces, the first media segment having a first curved edge portion and a first straight edge portion, the first media segment having an area defining a substantially circular first aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the first media segment having a first connection portion formed on either of the straight edge portions; and (b) a second media segment having first and second major faces, the first media segment having a second curved edge portion and a second straight edge portion, the second media segment having an area defining a substantially circular second aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the second media segment having a second connection portion formed on either of the straight edge portions, wherein the first and second media segments are operable to be brought into selective engagement by mating of the first and second straight edge portions, wherein an area defining a substantially circular third aperture is formed along a central axis of the first media disk when the first and second media segments are brought into selective engagement; and (2) a substantially circular second media disk, comprising: (a) a third media segment having first and second major faces, the third media segment having a third curved edge portion and a third straight edge portion, the third media segment having an area defining a substantially circular fourth aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the third media segment having a third connection portion formed on either of the straight edge portions; and (b) a fourth media segment having first and second major faces, the fourth media segment having a fourth curved edge portion and a fourth straight edge portion, the fourth media segment having an area defining a substantially circular fifth aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the fourth media segment having a fourth connection portion formed on either of the straight edge portions, wherein the third and fourth media segments are operable to be brought into selective engagement by mating of the third and fourth straight edge portions, wherein an area defining a substantially circular sixth aperture is formed along a central axis of the second media disk when the third and fourth media segments are brought into selective engagement, wherein the tip portions of the second plurality of members of the first media disk are operable to be received in the socket portions of the second plurality of members of the second media disk. 
     In accordance with a second embodiment of the present invention, a rotating biological contactor system is provided, comprising: (1) a substantially circular first media disk, comprising: (a) a first media segment having first and second major faces, the first media segment having a first curved edge portion and a first straight edge portion, the first media segment having an area defining a substantially circular first aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the first media segment having a first connection portion formed on either of the straight edge portions; (b) a second media segment having first and second major faces, the first media segment having a second curved edge portion and a second straight edge portion, the second media segment having an area defining a substantially circular second aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the second media segment having a second connection portion formed on either of the straight edge portions; and (c) a third media segment having first and second major faces, the third media segment having a third curved edge portion and a third straight edge portion, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the third media segment having a third connection portion formed on either of the curved edge portions, wherein the first and second media segments are operable to be brought into selective engagement by mating of the first and second straight edge portions, wherein the third media segment and any of the first and second media segments are operable to be brought into selective engagement by mating of the third curved edge portion with any of the first and second curved edge portions, wherein an area defining a substantially circular third aperture is formed along a central axis of the first media disk when the first and second media segments are brought into selective engagement; and (2) a substantially circular second media disk, comprising: (a) a fourth media segment having first and second major faces, the fourth media segment having a fourth curved edge portion and a fourth straight edge portion, the fourth media segment having an area defining a substantially circular fourth aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the fourth media segment having a fourth connection portion formed on either of the straight edge portions; (b) a fifth media segment having first and second major faces, the fifth media segment having a fifth curved edge portion and a fifth straight edge portion, the fifth media segment having an area defining a substantially circular fifth aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the fifth media segment having a fifth connection portion formed on either of the straight edge portions; and (c) a sixth media segment having first and second major faces, the sixth media segment having a sixth curved edge portion and a sixth straight edge portion, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the sixth media segment having a sixth connection portion formed on either of the curved edge portions, wherein the third and fourth media segments are operable to be brought into selective engagement by mating of the third and fourth straight edge portions, wherein the sixth media segment and any of the fourth and fifth media segments are operable to be brought into selective engagement by mating of the sixth curved edge portion with any of the fourth and fifth curved edge portions, wherein an area defining a substantially circular sixth aperture is formed along a central axis of the second media disk when the third and fourth media segments are brought into selective engagement, wherein the tip portions of the second plurality of members of the first media disk are operable to be received in the socket portions of the second plurality of members of the second media disk. 
     In accordance with a third embodiment of the present invention, a rotating biological contactor system is provided, comprising: (1) a substantially circular first media disk, comprising: (a) a first media segment having first and second major faces, the first media segment having a first curved edge portion and a first straight edge portion, the first media segment having an area defining a substantially circular first aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the first media segment having a first connection portion formed on either of the straight edge portions; (b) a second media segment having first and second major faces, the first media segment having a second curved edge portion and a second straight edge portion, the second media segment having an area defining a substantially circular second aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the second media segment having a second connection portion formed on either of the straight edge portions; (c) a third media segment having first and second major faces, the third media segment having a third curved edge portion and a third straight edge portion, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the third media segment having a third connection portion formed on either of the curved edge portions; and (d) a fourth media segment having first and second major faces, the fourth media segment having a fourth curved edge portion and a fourth straight edge portion, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the fourth media segment having a fourth connection portion formed on either of the curved edge portions, wherein the first and second media segments are operable to be brought into selective engagement by mating of the first and second straight edge portions, wherein the third and fourth media segments are operable to be brought into selective engagement by mating of the third and fourth straight edge portions, wherein any of the third and fourth media segments and any of the first and second media segments are operable to be brought into selective engagement by mating of any of the third and fourth curved edge portions with any of the first and second curved edge portions, wherein an area defining a substantially circular third aperture is formed along a central axis of the first media disk when the first and second media segments are brought into selective engagement; and (2) a substantially circular second media disk, comprising: (a) a fifth media segment having first and second major faces, the fifth media segment having a fifth curved edge portion and a fifth straight edge portion, the fifth media segment having an area defining a substantially circular fourth aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the fifth media segment having a fifth connection portion formed on either of the straight edge portions; (b) a sixth media segment having first and second major faces, the sixth media segment having a sixth curved edge portion and a sixth straight edge portion, the sixth media segment having an area defining a substantially circular fifth aperture formed therein, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the sixth media segment having a sixth connection portion formed on either of the straight edge portions; (c) a seventh media segment having first and second major faces, the seventh media segment having a seventh curved edge portion and a seventh straight edge portion, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the seventh media segment having a seventh connection portion formed on either of the curved edge portions; and (d) an eighth media segment having first and second major faces, the eighth media segment having an eighth curved edge portion and an eighth straight edge portion, the first major face having first and second pluralities of members extending therefrom, the second plurality of members having a greater height than the first plurality of members, the second plurality of members having a tip portion and an area defining a socket portion formed in a base portion thereof, the eighth media segment having an eighth connection portion formed on either of the curved edge portions, wherein the fifth and sixth media segments are operable to be brought into selective engagement by mating of the fifth and sixth straight edge portions, wherein the seventh and eighth media segments are operable to be brought into selective engagement by mating of the seventh and eighth straight edge portions, wherein any of the seventh and eighth media segments and any of the fifth and sixth media segments are operable to be brought into selective engagement by mating of any of the seventh and eighth curved edge portions with any of the fifth and sixth curved edge portions, wherein an area defining a substantially circular sixth aperture is formed along a central axis of the second media disk when the third and fourth media segments are brought into selective engagement, wherein the tip portions of the second plurality of members of the first media disk are operable to be received in the socket portions of the second plurality of members of the second media disk. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a partial perspective view of a rotating biological contactor system, in accordance with the general teachings of the present invention; 
         FIG. 2  is a sectional view of a rotating biological contactor system, in accordance with the general teachings of the present invention; 
         FIG. 3  is a schematic view of a rotating biological contactor system, in accordance with the general teachings of the present invention; 
         FIG. 4  is a plan view of a segment of a media element, in accordance with one embodiment of the present invention; 
         FIG. 5  is a plan view of the media element depicted in  FIG. 4 , showing only the support grid needed to hold the projecting elements in place, in accordance with one embodiment of the present invention; 
         FIG. 6  is a partial perspective view of the inside rim of the media element depicted in  FIG. 4 , wherein for clarity only the disk connecting members and the element connecting members are shown along with the structural grid, in accordance with one embodiment of the present invention; 
         FIG. 7  is the same view as  FIG. 6  with the projection support grid added thereto, in accordance with one embodiment of the present invention; 
         FIG. 8  is the same view as  FIGS. 6 and 7 , with all of the projecting elements shown, in accordance with one embodiment of the present invention; 
         FIG. 9  is a partial perspective view of the media element depicted in  FIG. 4 , wherein a media element connection portion is shown with the media element connecting members being shown on the edge, in accordance with one embodiment of the present invention; 
         FIG. 10  is a partial perspective view of the media element depicted in  FIG. 4 , wherein a media element connection portion is shown with the media element connecting member receiving apertures being shown on the edge, in accordance with one embodiment of the present invention; 
         FIGS. 11   a – 11   b  are partial perspective views of the primary steps involved with attaching one media element to an adjacent media element, in accordance with a first alternative embodiment of the present invention; 
         FIG. 12  is a partial perspective view of two adjacent media elements attached together, in accordance with a first alternative embodiment of the present invention; 
         FIG. 13  is a plan view of a three-foot media disk of the present invention fully assembled, wherein for clarity only the projection members, connection members, and grid structure are shown, in accordance with a second alternative embodiment of the present invention; 
         FIG. 14  is a sectional view of four adjacent media elements attached or about to be attached together, in accordance with a third alternative embodiment of the present invention; 
         FIG. 15  a sectional view of four adjacent media disks attached or about to be attached together, in accordance with a fourth alternative embodiment of the present invention; 
         FIG. 16  is a plan view of a six-foot media disk of the present invention using the three foot disk of  FIG. 15  and adding representative areas for the three to six foot interlocking media elements, in accordance with a fifth alternative embodiment of the present invention; 
         FIG. 17  is a plan view of a three-foot media element, in accordance with a sixth alternative embodiment of the present invention; 
         FIG. 18  is a plan view of a twelve-foot media disk of the present invention, wherein for clarity some of the respective segment boundaries are not shown, in accordance with a seventh alternative embodiment of the present invention; and 
         FIG. 19  is a plan view of a six-foot media disk segment, in accordance with an eighth alternative embodiment of the present invention. 
     
    
    
     The same reference numerals refer to the same parts throughout the various Figures. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     Referring to the drawings generally, and specifically to  FIGS. 1–3 , there is shown a rotating biological contactor system at  10 . The system  10  preferably includes a tank  12 , suitable for holding a desired amount of wastewater, having a fluid inlet  14  (e.g., for introducing untreated wastewater into the tank  12 ) and a fluid outlet  16  (e.g., for allowing treated wastewater to be removed from the tank  12 ). A selectively rotatable rotation shaft  18  is preferably provided, as well as a system  20  for rotating and/or controlling the rotation of the rotation shaft  18 . Although the rotation shaft  18  is shown as being substantially cylindrical, it should be appreciated that other configurations can be used in the practice of the present invention, such as but not limited to squares, rectangles, triangles, ovals, and the like. 
     Disposed about the rotation shaft  18 , are preferably at least one, and still more preferably, a plurality of media banks  22 . Although four media banks  22  are shown, it should be appreciated that either less than or more than this number can be used in the practice of the present invention. Each media bank  22  is preferably comprised of a pair of end plates  24 ,  26 , respectively, that envelope or “bookend” at least one, and still more preferably a plurality, of media disks  28 . By “end plate,” as that phrase is used herein, it is meant any member or members that are operable to contain the media disks  28 . 
     The media disks  28  are preferably comprised of a substantially rigid material, such as but not limited to plastic materials that are configured in substantially planar shapes. By “substantially rigid material,” as that phrase is used herein, it is meant any material that will not easily bend, flop, sag, fold, or otherwise cause the media disks  28  to undesirably contact one another. By “substantially planar shapes,” as that phrase is used herein, it is meant any shape that while being predominately planar can also contain projections extending from a major face thereof. 
     The media disks  28  are preferably provided with respective centrally located apertures  30  formed therein to receive the rotation shaft  18 . Although the apertures  30  are shown as being substantially cylindrical, it should be appreciated that other configurations can be used in the practice of the present invention, such as but not limited to squares, rectangles, triangles, ovals, and the like. 
     The media disks  28  preferably also include additional parallel apertures  32 , spaced from the central aperture  30 , that are operable to receive respective support shafts  34  (which are preferably secured to the end plates  24 ,  26 , respectively), thus allowing the media disks  28  to be sufficiently secured within the end plates  24 ,  26 , respectively. Although the apertures  32  are shown as being substantially cylindrical, it should be appreciated that other configurations can be used in the practice of the present invention, such as but not limited to squares, rectangles, triangles, ovals, and the like. Although the support shafts  34  are shown as being substantially cylindrical, it should be appreciated that other configurations can be used in the practice of the present invention, such as but not limited to squares, rectangles, triangles, ovals, and the like. 
     By way of a non-limiting example, once each media bank  22  is assembled, it can then be placed on the rotation shaft  18 . In the present views, there are four media banks  22  of varying width, and are generally denominated as stage one  36 , stage two  38 , stage three  40 , and stage four  42 , each appropriate for a particular stage of the biodegradation process. Although the media banks  22  are shown with varying widths, it should be appreciated that their respective widths can be modified to suit the particular processing requirements of the respective RBC system. 
     Once all of the media banks  22  are loaded onto the rotation shaft  18 , the system  10  is ready for operation. The media of the present invention is typically located such that about forty percent of the media is immersed in the wastewater to be treated. As various portions of the media banks  22  rotate slowly into and out of the wastewater, microorganisms attach themselves to the media, forming a biomass, and consuming contaminates from the wastewater. As the Media banks  22  rotate into the air above the tank  12 , the microorganisms biodegrade these contaminates, e.g., into carbon dioxide and water. It is clear that, the larger the population of microorganisms exposed to the wastewater, the larger the amount of contaminates that can be removed from the wastewater through conventional RBC techniques. 
     The rotation of the media disks  28  into and through the wastewater applies a combination of shear and impact forces, as specifically shown in  FIG. 2 . This is due, in part, to the particular effect of the surface projections disposed on the surface of the media disks  28 , as will be explained further herein. In this manner, the system  10  of the present invention best utilizes the direction of this applied cleansing force and has the best chance of maintaining design capacity by preventing or at least lessening the plugging of the system  10 . Referring generally to the drawings generally, and specifically to  FIGS. 4–10 , there is shown a media element  100 , in accordance with one embodiment of the present invention. It is preferred that the previously described media disks  28  are comprised of at least one, more preferably at least two, and still more preferably a plurality of media elements  100 , as will be described herein. 
     The media element  100  is preferably comprised of a substantially planar wedge-shaped member  102  having a first major face  104  and a second major face  106 . The media element  100  preferably includes a discontinuous surface, such as but not limited to a mesh-like grid support member  108 . The media element  100  can be comprised of any number of suitable materials, such as but not limited to plastic materials. Preferably, the material chosen is substantially rigid regardless of the configuration of the media element  100  (e.g., solid disk, mesh-like disk or the like). 
     The member  102  preferably includes at least one, and more preferably at least two curved connection portions  110 ,  112 , respectively, and preferably includes at least one, and more preferably at least two straight connection portions  114 ,  116 , respectively, extending outwardly away parallel to the plane of the member  102 . The intended purpose of these connection portions  110 ,  112 ,  114 ,  116 , respectively, will be described in detail herein. The connection portions  110 ,  112 ,  114 ,  116 , respectively, can be formed on a flange or flange-like structure extending outwardly parallel from the body of the member  102 . The degree of curvature of the curved portions will vary, depending, in part, on the exact configuration of the media disk to be assembled. 
     Any of the connection portions  110 ,  112 ,  114 ,  116 , respectively, can be provided with either media element connection members  118  (e.g., cones or the like) or media element connection member receiving apertures  120  (e.g., throughbores or the like). In this manner, the media elements  100  can be connected to any adjacent media element  100 , as will be described in detail herein. Additionally, an area defining an aperture  122  can be provided for receiving a support shaft  124 . 
     On the first major face  104 , a plurality of outwardly extending projection members  200  are preferably formed thereon, e.g., by blow molding or other suitable processes. These projection members  200  are preferably formed into relatively small diameter cones, rods, cylinders and the like, having base portions  202  and tip portions  204 . The first major face  104  preferably lays in a plane perpendicular to the rotation shaft  18  and the projection members  200  are preferably spaced throughout its surface. The location and spacing of the projection members  200  are preferably configured so as to prevent biomass webbing between adjacent projection members  200 . By way of a non-limiting example, the intended function of the projection members  200  is to permit microorganisms to attach thereto. It should also be appreciated that the projection members  200  can be angled with respect to the surface of the first major face   104  (i.e., in a non-perpendicular orientation). 
     Also on the first major face  104 , a plurality of outwardly extending disk connection members  300  are preferably formed thereon, e.g., by blow molding or other suitable processes. The disk connection members  300  are preferably formed into relatively larger diameter elongated cones that have socket portions  302  formed in their bases  304 . The disk connection members  300  are operable to connect one media disk   28  to another media disk  28  when a tip portion  306  of one media disk  28  is inserted into a corresponding socket portion  302  of an adjacent media disk  28 , as will explained in further detail herein. The disk connection members  300  are also intended to function, in part, as a definitive and consistent media disk spacing element and also enable the disk bank  22  to function as a monolithic unit or disk. By way of a non-limiting example, this spacing, which can range from 0.03 inches from the tip portion  204  of the projection members  200  to the face of the next media disk  28  in high density media to 0.5625 inches in low density media, provides a direct path for the sloughed biomass to be washed out of the media banks  22 . It should be appreciated that this range is for illustrative purposes only, and is not meant to be limiting. 
     In order to form a media disk  28  of the present invention, it is preferable to connect at least two, and more preferably, a plurality of the media elements  100  together. Referring to  FIGS. 11   a ,  11   b  and  12 , there are shown the primary steps involved with attaching one media element  400  to an adjacent media element  500  along an adjacent straight connection portion, in accordance with a first alternative embodiment of the present invention. In  FIG. 11   a , the respective media elements  400 ,  500 , respectively, are manipulated so that media element connection member  402  is introduced into the media element connection member receiving aperture  502 . In  FIG. 11   b , the respective media elements  400 ,  500 , respectively, are further manipulated so that media element connection member receiving aperture  502  is brought into a substantially flush arrangement with the surface adjacent to the base portion  404  of the media element connection member  402  so as to form a frictional engagement therebetween. In this manner, the media element  400  can be joined to the media element  500  along an adjacent straight connection portion, as specifically shown in  FIG. 12 . However, it should be appreciated that the same exact methodology can be used to connect adjacent media elements along an adjacent curved connection portion. 
     As more and more of the media elements are assembled together along the straight connection portions thereof, a fully formed media disk  600  is completed, as specifically shown in  FIG. 13 , in accordance with a second alternative embodiment of the present invention. In this view, a three-foot diameter media disk  300  is shown, however, it should be appreciated that any size media disk could be configured in accordance with the general teachings of the present invention. Additionally, in this view six individual media elements  602 ,  604 ,  606 ,  608 ,  610 , and  612 , respectively, are shown comprising the media disk  600 . However, it should be appreciated that either less than or more than this number of media elements can be used to form the media disk  600 . Additionally, an aperture  614  (for receiving the rotation shaft  616 ) is formed when all of the requisite number of media elements are brought into engagement as previously described. Furthermore, the apertures  618  formed in the respective media elements, for receiving the corresponding support shafts   620 , are also clearly shown. 
     Because the Media banks  22  are typically comprised of several, if not dozens or hundreds of individual media disks  28 , it is sometimes necessary to connect several adjacent media disks  28  in a manner that will impart stability and rigidity to the media disks  28  as a whole, so as to lessen or eliminate any “floppiness” therein. Referring to  FIG. 14 , there are shown four adjacent media elements  700 ,  702 ,  704 ,  706 , respectively, attached together or about to be attached together, in accordance with a third alternative embodiment of the present invention. As previously noted, attaching one media element to another media element is rather straightforward, and merely requires that the tip portion  708  of a disk connection member  710  of one media element is inserted into the corresponding socket portion  712  of the disk connection member  714  of the adjacent media element. The connection between the tip portion  708  and the socket portion  712  can be a frictional engagement, a snap fit engagement, and the like. Although four media elements are shown in this view, it will be appreciated that any number of media elements can be connected together in accordance with the general teachings of the present invention. 
     Also as previously noted, because the media banks  22  are typically comprised of several, if not dozens or hundreds of individual media disks  28 , it is sometimes necessary to connect several adjacent media disks  28  in a manner that will impart stability and rigidity to the media disks  28  as a whole, so as to lessen or eliminate any “floppiness” therein. Referring to  FIG. 15 , there are shown four adjacent media disks  800 ,  802 ,  804 ,  806 , respectively, attached together or about to be attached together, comprised of eight individual media elements  808 ,  810 ,  812 ,  814 ,  816 ,  818 ,  820 ,  822 , respectively, in accordance with a fourth alternative embodiment of the present invention. As previously noted, attaching one media disk and/or media element to another media disk and/or media element is rather straightforward, and merely requires that the tip portion  824  of a disk connection member  826  of one media element is inserted into the corresponding socket portion  828  of the disk connection member  830  of the adjacent media element. The connection between the tip portion  824  and the socket portion  828  can be a frictional engagement, a snap fit engagement, and the like. Although four media disks are shown in this view, it will be appreciated that any number of media disks can be connected together in accordance with the general teachings of the present invention. 
     Because it is sometimes necessary to provide media disks having relatively larger diameters, e.g., larger than the three-foot media disk depicted in  FIG. 13 , it is sometimes necessary to connect two or more adjacent media elements together in a manner that will increase the overall diameter of the media disk. Preferably, this should be done in a manner so as to impart stability and rigidity to the media disk as a whole, as well as to lessen or eliminate any “floppiness” therein. Accordingly, these additional media elements should be comprised of materials as previously described. Referring to  FIG. 16 , there is shown a six-foot media disk  900  of the present invention using a similar three-foot disk similar to that depicted in  FIG. 13  and adding representative areas for the three to six foot interlocking media elements  902 ,  904 ,  906 ,  908 ,  910 ,  912 ,  914 ,  916 ,  918 ,  920 ,  922 ,  924 , respectively, in accordance with a fifth alternative embodiment of the present invention. Of course, the media elements  902 ,  904 ,  906 ,  908 ,  910 ,  912 ,  914 ,  916 ,  918 ,  920 ,  922 ,  924 , respectively, would be provided with the same type of grid support, segment connection portions, projection members, disk connection members, and the like, as in previously described embodiments, the same being omitted for clarity purposes. The respective media elements are preferably joined along their mating curved connection portions  926 ,  928 , respectively, as described in previous embodiments (e.g., connection members received in corresponding apertures). Additionally, the three to six foot interlocking media elements  902 ,  904 ,  906 ,  908 ,  910 ,  912 ,  914 ,  916 ,  918 ,  920 ,  922 ,  924 , respectively, can be provided with apertures (not shown for clarity purposes) for receiving support shafts (not shown for clarity purposes). 
     Referring to  FIG. 17 , there is shown a three-foot media element  1000 , in accordance with a sixth alternative embodiment of the present invention. This media element  1000  is comprised of a unitary member that is roughly equivalent to two of the media elements depicted in  FIG. 4 . In this manner, fewer discrete media elements are required to form a media disk (e.g., three media elements versus six media elements). It should be appreciated that the three-foot media element  1000  is preferably configured with two curved connection portions  1002 ,  1004 , respectively, and two straight connection portions  1006 ,  1008 , respectively. In this view, two apertures  1010 ,  1012 , respectively, are provided for accepting any corresponding support shafts. However, it should be appreciated that either less than or more than this number of apertures can be provided. Although the apertures  1010 ,  1012 , respectively, are shown as being substantially cylindrical, it should be appreciated that other configurations can be used in the practice of the present invention, such as but not limited to squares, rectangles, triangles, ovals, and the like. The degree of curvature of the curved connection portions  1002 ,  1004  will vary, depending, in part, on the exact configuration of the media disk to be assembled. It should be appreciated though, that if multiple rings of media elements are employed, the respective mating curved connection portions should be compatible with respect to their respective curvatures. 
     Because it is sometimes necessary to provide media disks having even relatively larger diameters, e.g., larger than the six-foot media disk depicted in  FIG. 16 , it is sometimes necessary to connect multiple adjacent media elements together in a manner that will greatly increase the overall diameter of the media disk. Preferably, this should be done in a manner so as to impart stability and rigidity to the media disk as a whole, as well as to lessen or eliminate any “floppiness” therein. Accordingly, these additional media elements should be comprised of materials as previously described. Referring to  FIG. 18 , there is shown a twelve-foot media disk  1100  of the present invention using a similar six-foot disk depicted in  FIG. 16  and adding representative areas for the six to nine foot interlocking media elements  1102 ,  1104 , respectively, and the nine to twelve foot interlocking media elements  1106 ,  1108 , respectively, in accordance with a seventh alternative embodiment of the present invention. Of course, the media elements  1102 ,  1104 ,  1106 ,  1108 , respectively, would be provided with the same type of grid support, segment connection portions, projection members, disk connection members, and the like, as in previously described embodiments, the same being omitted for clarity purposes. As with the previously described embodiments, the respective additional media elements are preferably joined along their mating curved connection portions  1110 ,  1112 ,  1114 ,  1116 , respectively, as described in previous embodiments (e.g., connection members received in corresponding apertures). Additionally, the six to nine and nine to twelve foot interlocking media elements  1102 ,  1104 ,  1106 ,  1108 , respectively, can be provided with apertures (not shown for clarity purposes) for receiving support shafts (not shown for clarity purposes). 
     Referring to  FIG. 19 , there is shown a six-foot media element  1200 , in accordance with an eighth alternative embodiment of the present invention. As with the embodiment of  FIG. 17 , this media element  1200  is also comprised of a unitary member that is roughly equivalent to two individual media elements of similar size and curvature. In this manner, fewer discrete media elements are required to form a media disk (e.g., six media elements versus twelve media elements). It should be appreciated that the six-foot media element  1200  is preferably configured with two curved connection portions  1202 ,  1204 , respectively, and two straight connection portions  1206 ,  1208 , respectively. In this view, two apertures  1210 ,  1212 , respectively, are provided for accepting any corresponding support shafts. However, it should be appreciated that either less than or more than this number of apertures can be provided. Although the apertures  1210 ,  1212 , respectively, are shown as being substantially cylindrical, it should be appreciated that other configurations can be used in the practice of the present invention, such as but not limited to squares, rectangles, triangles, ovals, and the like. The degree of curvature of the curved connection portions  1202 ,  1204  will vary, depending, in part, on the exact configuration of the media disk to be assembled. It should be appreciated though, that if multiple rings of media elements are employed, the respective mating curved connection portions should be compatible with respect to their respective curvatures. 
     It should be appreciated that the present invention also envisions the use of media disks having diameters that are smaller than three feet and greater than twelve feet, as well as the various three feet to twelve feet embodiments specifically disclosed herein. 
     With respect to the operation of the system  10 , the media of the present invention takes direct advantage of the direction of the washing force of the pool of wastewater. The base of the media disk acts as a rigid mesh which is cleaned by the shear force of the water as it passes through. The projecting elements are perpendicular to the direction of rotation and are thus perpendicular to the direction of flow through the wastewater. This orientation presents the maximum surface area to the wastewater it is passing through and thus induces the maximum velocity to the fluid flowing over the projections. This velocity of flow controls the thickness of the biomass attached to the projections and also reduces the chance of biomass webs forming between adjacent projections. 
     The foregoing description and the Figures show that the various embodiments of the present invention are well suited to fulfill their objectives and achieve the advantages stated above. It is recognized that those skilled in the art may make various modifications or additions to the exemplary embodiments chosen to illustrate the present invention without departing from the spirit and proper scope of the invention. For example, the size of the overall devices and/or assemblies and/or the components (that is, parts) thereof can be varied in somewhat different arrangements for the connecting the sheets together and/or supporting the various parts or components and may be utilized for accomplishing many of the same basic objectives and advantages. Most of the components or parts shown can be made of various plastics, ceramics, selected metals or any other suitable moldable, machinable and/or formable material known or used for wastewater media or rotating biomass support structures. Accordingly, it is to be understood that the protection that is to eventually be sought through the patent system and to be afforded hereby should be deemed to extend to novel and unobvious aspects of the subject matter disclosed herein, including all fair equivalents thereof. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.