WO2011032090A1

WO2011032090A1 - Apparatus and methods for treatment of a waste stream

Info

Publication number: WO2011032090A1
Application number: PCT/US2010/048631
Authority: WO
Inventors: Daniel E. Wickham; William S. Paulson; William E. Wood
Original assignee: Wabtec Holding Corp.
Priority date: 2009-09-11
Filing date: 2010-09-13
Publication date: 2011-03-17

Abstract

An apparatus (10) for the treatment of a waste stream (W), including: a housing (12) having an inner area (14); a waste inlet (16) configured to convey the waste stream (W) to the inner area (14) of the housing (12); a plurality of bio-media members (18) positioned in the inner area (14) of the housing and configured to contact at least a portion of the waste stream (W) and at least partially separate solid waste material (SW) from liquid waste material (LW); a recirculation arrangement (20) configured to convey at least a portion of the liquid waste material (LW) through or over the plurality of bio-media members (18); and an effluent discharge (22) configured to remove at least a portion of the liquid waste material (LW). Methods (100) of treating a waste stream (W) are also disclosed.

Description

APPARATUS AND METHODS FOR TREATMENT OF A WASTE STREAM

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates generally to waste material and sewage treatment systems and arrangements and, more particularly, to devices, apparatuses, and methods for the treatment of waste materials, such as waste materials generated in a toilet system and/or other waste treatment or processing systems.

Description of the Related Art

[0002] Various types of public transit carry large populations that require waste facilities during their transit period, including trains, airplanes, buses, and the like. Many such vehicles or vessels serve this need by carrying holding tanks that receive and store such waste until they can be delivered to processing facilities. The expansion of public transit, however, has resulted in an increased production of waste volume that can no longer be accommodated by many public treatment facilities. Therefore, alternative solutions are increasingly needed, including a need for portable treatment devices and units for providing accelerated or advance treatment of waste streams.

[0003] Another issue that arises in the treatment of certain waste streams, including waste streams with both a liquid waste component and a solid waste component (e.g., human waste having fecal matter and urine), is the inability to effectively sequester particulate solids from the liquid material for aerobic digestion. These particulate solids have a slow degradation rate due to the size of the particles and the limited ability to move dissolved oxygen to the digestive surface. Still further, such waste streams often include large particles and solid material that also leads to a slow degradation rate. Therefore, maceration may be used to assist in impacting and breaking apart these large particles and solid material into smaller particles. Accordingly, there remains a need in the art for treatment systems that increase the degradation rate of solid waste materials through enhanced biological digestion and/or mechanical maceration processes.

[0004] One example of a known waste treatment process and apparatus is taught in U.S. Patent No. 3,238,124. In particular, the Ί24 patent is directed to a portable toilet/treatment unit, which uses particular features of tree bark fiber as a medium to treat waste within a device, thereby allowing disposal of the treated waste directly from the unit. A problem associated with this prior treatment unit is that it utilized long, decorticated fibers of redwood tree bark, which is best obtained from larger, old growth forests. As this resource has become less available and more expensive, a need has grown to find alternative materials and new designs for operation of such a device. In addition, as redwood bark is a natural product, it breaks down over time. Accordingly, a need has grown for alternative synthetic materials for the above purpose, and an ongoing need for improvements in the waste treatment processing field.

SUMMARY OF THE INVENTION

[0005] Generally, the present invention includes an apparatus and methods for treatment of a waste stream that addresses or overcomes some or all of the deficiencies of prior art systems and methods in the field of waste treatment. Preferably, the present invention includes an apparatus and methods for treatment of a waste stream that provides a portable apparatus and device for use in the treatment of waste streams generated in a transit environment. Preferably, the present invention includes an apparatus and methods for treatment of a waste stream that effectively separates solid particles (or solid waste material) from a liquid waste material in a mixed waste stream. Preferably, the present invention includes an apparatus and methods for treatment of a waste stream that provides enhanced biological digestion of solid waste materials. Preferably, the present invention includes an apparatus and methods for treatment of a waste stream that provides enhanced mechanical maceration of solid waste material.

[0006] Accordingly, and in one preferred and non-limiting embodiment, the present invention provides an apparatus for the treatment of a waste stream. The apparatus includes: a housing having an inner area; a waste inlet configured to convey the waste stream to the inner area of the housing; a plurality of bio-media members positioned in the inner area of the housing and configured to contact at least a portion of the waste stream and at least partially separate solid waste material from liquid waste material; a recirculation arrangement configured to convey at least a portion of the liquid waste material through or over the plurality of bio-media members; and an effluent discharge configured to remove at least a portion of the liquid waste material.

[0007] In another preferred and non-limiting embodiment, provided is a method for the treatment of a waste stream. This method includes: contacting at least a portion of the waste stream with at least one of a plurality of bio-media members to thereby at least partially separate solid waste material from liquid waste material; and recirculating at least a portion of the liquid waste material through or over the plurality of bio-media members.

[0008] These and other features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Fig. 1 is a schematic view of one embodiment of an apparatus for the treatment of a waste stream according to the principles of the present invention;

[0010] Fig. 2 is a perspective view of another embodiment of an apparatus for the treatment of a waste stream according to the principles of the present invention, with certain portions removed for clarity;

[0011] Fig. 3 is a partially exploded, perspective view of the apparatus of Fig. 2;

[0012] Fig. 4 is a side sectional and schematic view of the apparatus of Fig. 2;

[0013] Fig. 5 is a partial, side sectional view of the apparatus of Fig. 2;

[0014] Fig. 6 is a plan view of a portion of another embodiment of an apparatus for the treatment of a waste stream according to the principles of the present invention;

[0015] Fig. 7 is a partial, side sectional view of the apparatus of Fig. 6;

[0016] Fig. 8 is side sectional view of one embodiment of an overflow arrangement in an apparatus for the treatment of a waste stream according to the principles of the present invention;

[0017] Fig. 9 is a perspective view of the overflow arrangement of Fig. 8; and

[0018] Fig. 10 is a box diagram illustrating one embodiment of a method for the treatment of a waste stream. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] For purposes of the description hereinafter, the terms "end", "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal" and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

[0020] The present invention is directed to an apparatus 10 and methods for treating a waste stream, such as sewage, human waste, toilet waste, fecal matter, urine, mixed waste streams, solid waste material, liquid waste material, a waste slurry, and the like. Further, the presently-invented apparatus 10 and methods are useful in a variety of applications and environments. For example, in one preferred and non-limiting embodiment, the apparatus 10 and methods are embodied in a portable device that is useful in transit applications, including waste facilities situated on or in connection with trains, airplanes, buses, and the like.

[0021] It is further envisioned that the apparatus 10 and methods of the present invention can be used as a component or unit operating in a more complete waste processing and treatment environment or plant. For example, the apparatus 10 and methods can be used as a unit that is placed inside or adjacent a conventional liquid sewage treatment plant, such that solid waste material can be diverted to the unit for independent treatment outside of the main treatment process. Accordingly, the presently-invented apparatus 10 and methods could be used as a standalone unit/process, or integrated into a large, comprehensive waste treatment system and process. Various preferred and non-limiting embodiments of the present invention are illustrated in Figs. 1-10.

[0022] One preferred and non- limiting embodiment of an apparatus 10 according to the present invention is illustrated in schematic form in Fig. 1. In particular, the apparatus 10 includes a housing 12 having an inner area 14. This housing 12 may be in the form of a frame or body having the appropriate material of construction and arrangement to operatively associate the various components of the apparatus 10, as discussed hereinafter. Further, the housing 12 may be in the form of a modular construction, such that various additional components, treatment units, treatment areas, and the like can be used in connection therewith.

[0023] The apparatus 10 further includes a waste inlet 16 for conveying a waste stream W (having a solid waste material SW component and a liquid waste material LW component) from a waste source WS to the inner area 14 of the housing 12. In a preferred embodiment, this waste inlet 16 is positioned at or near the top of the housing 12 and gravity or pressurized flow is used to move the waste stream W from the waste source WS to the inner area 14 of the housing 12.

[0024] The apparatus 10 further includes a plurality of bio-media members 18 positioned in the inner area 14 of the housing 12, and these bio-media member 18 are used to contact at least a portion of the waste stream W and at least partially separate the solid waste material S W from the liquid waste material LW. By using multiple bio-media members 18, the solid or particulate matter is removed from the liquid waste material LW (if it is suspended therein) as the liquid waste material LW moves through and/or over the bio- media members 18 in series. Therefore, at least a portion of the solid waste material SW is retained by or captured on one or more of the bio-media members 18.

[0025] Further, the bio-media members 18 may take a variety of forms and materials of construction. For example, the bio-media members 18 may be in the form of panels 19 that are stacked, spaced apart, and/or sloped. In addition, these panels 19 may be in the form of or include a surface or body in the form of one or more of the following: a woven mesh, a waffle-patterned layer, a fabric material, a screen material, a perforated material, a digestive material, a course material, a porous material, or any combination thereof.

[0026] A recirculation arrangement 20 is provided and used to convey at least a portion of the liquid waste material LW (together with any suspended or "non-separated" solid waste material SW, settled solid waste material SW, and/or in the form of a slurry or the like) back through and/or over the bio-media members 20. This recirculation operation serves multiple functions, including, but not limited to: (1) providing the additional clarification or separation of the solid waste material SW and the liquid waste material LW by multiple passes through and/or over the bio-media members 18; (2) providing maceration by impacting the recycled liquid waste material (together with any suspended or "non-separated" solid waste material SW, settled solid waste material SW, and/or in the form of a slurry or the like) against the larger, remaining portions of solid waste material SW captured at the beginning of contact with the bio-media members 18; and (3) assisting in moving the waste stream W through and/or over the bio-media members 18, such as when using the cascade arrangement (discussed hereinafter). The recirculation arrangement 20 may take a variety of forms and structures, and the present invention is not limited to any particular structure or arrangement.

[0027] An effluent discharge 22 is provided for removing at least a portion of the liquid waste material LW after processing through the bio-media members 18. This effluent discharge 22 is normally positioned at or near the bottom of the housing 12 and allows the liquid waste material LW to be moved to a storage location or to an additional treatment unit. A drain 21 may also be used to provide quick removal of liquids from the inner area 14 of the housing 12 of the apparatus 10.

[0028] One preferred and non-limiting embodiment of an apparatus 10 according to the present invention is illustrated in Figs. 2-6. In this embodiment, the apparatus 10 is provided for use in connection with a waste source WS in the form of a conventional toilet arrangement. Accordingly, the apparatus would be included within a tank of a conventional toilet (not shown) or toilet system. The apparatus 10 may be particularly adapted to reduce or eliminate pathogens from a waste stream W typically introduced into a conventional toilet.

[0029] Further, the apparatus 10 may include one or more additional treatment units 23 attached to or operatively engaged (i.e., in fluid communication) with the housing 12, For example, as shown in Figs 2 and 3, the additional treatment unit 23 is in the form of a sterilization unit. However, any further unit or device may be integrated with or in fluid communication with the housing 12 or apparatus 10, such as a retention chamber or the like. Such an arrangement will provide a substantial reduction of pathogens present within the apparatus 10 before releasing to the environment. In one preferred and non-limiting embodiment, the apparatus 10 may serve as a pre-treatment for advance or accelerated purification of the effluent. This may be particularly advantageous in situations in which a final treatment system cannot handle a high solids loading.

[0030] As further illustrated in Figs. 2 and 3, a front cover (not shown) may be removed from the housing 12, and the bio-media members 18 removed for cleaning and/or maintenance. As shown, in one embodiment, the bio-media members 18 can be removed as a unit (or as connected panels 19) from the housing 12, but alternatively, may be removed individually. Further, in order to properly position the bio-media members 18 (whether as a unit or separately) in the inner area 14 of the housing 12, any number of removably connection arrangements may be utilized. For example, when the bio-media members 18 are in the form of panels 19, these panels 19 can rest on or contact a lip, ledge, shelf, projection, or the like.

[0031] hi a further preferred and non-limiting embodiment, and as illustrated in Fig. 4, the apparatus 10 includes a porous packet 24 of inoculum material. In one embodiment, this inoculum material is in the form of a culture of facultative bacteria, which is preferably introduced in the apparatus 10 adjacent or on an upper bio-media member 26. The facultative bacteria can be rapidly propagated by the packet 24, and provides nourishment for the bacterium of the bio-media members 18, such as when the apparatus 10 is not in use. In a further embodiment, the liquid waste material LW may be directed over the packet 24 of bacterial inoculum, such that the liquid moisturizes and feeds the bacteria, causing release into the liquid waste material LW in the apparatus. It is further noted that this packet 24 can be positioned anywhere in the apparatus 10 or on any of the bio-media members 18. For example, the packet 24 can be positioned on or near the discharge from the recirculation arrangement 20. Further, the facultative bacteria from the porous packet 24 may be distributed across and throughout the bio-media members 18.

[0032] In another preferred and non-limiting embodiment, in addition to the upper bio- media member 26, multiple secondary bio-media members 28 are provided, i operation, the waste stream W moves through and/or over each bio-media members 24, 26 in series, with each bio-media member 24, 26 separating or retaining additional and finer solid waste material SW. In the embodiment of Fig. 4, the bio-media members 18 are positioned and configured to permit at least a portion of the waste stream W (normally the liquid waste stream (LW) (together with any suspended or "non-separated" solid waste material SW, settled solid waste material SW, and/or in the form of a slurry or the like)) to cascade through and/or over the upper bio-media member 24 and each subsequent, secondary bio- media member 26 in turn. As discussed, this "cascade" effect, which is illustrated by the arrows in Fig. 4, is further enhanced by the recirculation arrangement 20, as discussed hereinafter. Still further, such an arrangement allows the bio-media members 18 to act like filtering elements to clarify the liquid waste material LW, and the cascade arrangement allows the bio-media members 18 to be biologically self-cleaning, since the solid waste material SW is converted to C0₂ over time. In addition, by holding the solid waste material SW above the liquid waste material LW, oxygen is made available at atmospheric concentrations that are significantly higher than what can be dissolved in water. Again, this aids in the digestive process.

[0033] In one preferred and non-limiting embodiment, one or more of the bio-media members 18 are formed with a specified porosity so as to allow at least a portion of the liquid waste material LW pass therethrough, whether in the initial pass or during the recirculation process. For example, the upper bio-media member 26 may be formed from a course material for enhancing the maceration process of the solid waste material SW as the waste stream W is pushed over it, as well as porous to allow the liquid waste material LW (as well as certain-sized particles) to pass therethrough and drop down to the next secondary bio-media member 28. In another embodiment, the porosity of the bio-media members 18 may be varied to avoid or enhance clogging and/or retention.

[0034] In operation, the bio-media members 18, such as panels 19, sequentially remove particulate (solid waste material SW) from the hquid (liquid waste material LW), and retain the solid waste material SW in the aerobic zone to facilitate conversion of the material by digestion to carbon dioxide. As discussed, the bio-media members 18 may be graded, such that the pores present within the secondary bio-media members 28 are finer than the pores present within the higher secondary bio-media members 28 or the upper bio-media member 26. It is noted herein that any suitable number of bio-media members 18 or panels 19 may be provided to allow for proper filtration of the solid waste material SW in the waste stream W.

[0035] As illustrated in Fig. 4, at least a portion of the liquid waste material LW passes through the bio-media members 18, and at least a portion of the solid waste material SW is captured therein or thereon. This "trickling zone" is positioned above the bottom area of the housing 12. As further illustrated in Fig. 4, the apparatus 10 includes a vent 30 for facilitating the removal of air and other gases from the inner area 14 of the housing 12. h a preferred and non-limiting embodiment, the vent 30 is positioned at or near the top of the housing 12 to create airflow up through the bio-media members 18. In particular, the vent 30 forces airflow to pass over the porous bio-media members 18 and provide aerobic conditions to foster digestive activity by bacteria attaching to the bio-media member 18 surfaces as a fixed film. In this manner, air passes over the bio-media members 18 and facilitates aerobic digestion of the organic material present in the waste stream W. Further, the porosity of the bio-media members can be chosen to maximize exposure to air, thereby increasing the digestion of captured particulate organic material and soluble organic matter, as the liquid waste material LW portion passes over the bacterial fixed film.

[0036] The discharge from the waste source WS and waste inlet 16 are preferably positioned such that solid waste material SW (e.g., toilet paper and fecal material) are captured at the surface of the upper bio-media member 26. In some embodiments, a flush valve 32 may be mounted directly to the tank of the toilet (not shown) or to the housing 12.

[0037] Figs. 4 and 5 illustrate one preferred and non-limiting embodiment of the recirculation arrangement 20, which includes an airlift pump 34 for capturing, circulating, and directing bacterially-activated liquid waste material LW from a recirculation basin 36 to upper area of the housing 12 above the upper bio-media member 26. As discussed, by discharging this liquid waste material LW above and towards the upper bio-media member 26, further degradation of the solid waste material SW is achieved as liquid waste material LW impacts and gently macerates the solid waste material SW. The shearing or impact force incurred by the recirculated liquid waste material LW (together with any suspended or "non-separated" solid waste material SW, settled solid waste material SW, and/or in the form of a slurry or the like) assists in slowly breaking down fibers and particles, thereby further exposing them to bacterial digestion.

[0038] In the embodiment of Figs. 4 and 5, the pump 34 includes a bell portion 38 for receiving air from an air pump 40, specifically through a hose 42 attached at the top of the bell portion 38. A pipe 44 includes a first end 46 positioned above a bottom of the bell portion 38 and extending through the top of the bell portion 38. Specifically, the first end 46 of the pipe 44 is positioned at a predetermined distance above the bottom of the bell portion 38. The pipe 44 extends to an elbow 48 positioned above the surface of the upper bio-media member 26. A discharge pipe 50 extends into the upper area of the housing 12 and over the upper bio-media member 26.

[0039] In operation, liquid waste material LW flows in to the pipe 44 and fills it to a level equal to the fill line or waterline of the recirculation basin 36. In particular, the liquid waste material LW (together with any suspended or "non-separated" solid waste material SW, settled solid waste material SW, and/or in the form of a slurry or the like) is conveyed to the pump 34 through one or more passages 37. As air enters the top of the bell portion 38, a bubble is created and passes down until it reaches the first end 46 of the pipe 44. Since the outside of the bell portion 38 is lower than the level of the pipe 44, the air pushes upward through the pipe 44, evacuating and urging the liquid waste material LW above it as it does so. This pulses the liquid waste material LW up and out through the elbow 48 and discharge pipe 50 and onto the upper surface of the upper bio-media member 26, on which solid waste material SW (e.g., fecal solids) have been captured. The relative diameters of the various pipes and conduits in the apparatus 10 may be adjusted to reduce the propensity of the apparatus to clog with bio-solids.

[0040] In a further preferred and non-limiting embodiment, the flow of liquid waste material LW through the apparatus 10 may be controlled by regulating the amount of air delivered to the pump 34 by the air pump 40. For example, a control device 52 can be used to control air delivery, air rate, air volume, air flow, and the like. This provides for the adjustment of the various characteristics of the apparatus 10 in operation.

[0041] As shown in Fig. 6, the recirculation arrangement 20 includes two pumps 34 and associated passages 37 for delivering liquid waste material LW to the pump 34. Accordingly, each pump 34 is associated with a respective discharge pipe 50, and these pipes 50 can be specifically positioned to enhance the functionality discussed above. Further, both pumps 34 operate as described above, and lead to an increase efficiency in the apparatus 20.

[0042] With continued reference to Fig. 4, the recirculation basin 36 may include sloped walls 53, such that solid waste material SW, such as solid particles and the like, will settle from the liquid waste material LW prior to passage through the overflow arrangement (as discussed hereinafter). Instead, these solid waste material SW particles slowly descend to a bottom area 55 of the recirculation basin 36. The opening to the passages 37 may be situated at or near this bottom area 55 in order to capture and recycle any particulate material back up and over the bio-media members 18. Such an arrangement is illustrated in Fig. 6.

[0043] In a still further preferred and non- limiting embodiment, the apparatus 10 includes a diffusion arrangement 54, as illustrated in Figs. 4 and 7. In this embodiment, the diffusion arrangement 54 includes an air diffuser in the form of a perforated hose 56. Air is delivered from an air pump 58, which also may be controlled through the control device 52. In operation, pressurized air is ported to the hose 56, which is positioned in or near the recirculation basin 36. Further, this diffusion arrangement 54 is configured to aerate the liquid waste material LW in the recirculation basin 36, thus providing aerobic conditions favorable to the growth of the introduced bacteria. The air pumps 40, 58 (whether alone or collectively) will generate a positive pressure inside the apparatus 10. Therefore, the vent 30 is used and located such that airflow will pass over and through the bio-media members 18 in the trickling zone.

[0044] New liquid waste material LW entering the apparatus 10 as the toilet (waste source WS) is flushed will increase the liquid depth in the recirculation basin 36. Accordingly, an overflow arrangement 60 is provided to convey liquid waste material LW directly or indirectly from the recirculation basin 36 to the effluent discharge 22. This overflow arrangement 60 allows the liquid waste material LW in the recirculation basin 36 to flow out as it is displaced with new liquid waste material LW entering the apparatus 10.

[0045] In one preferred and non-limiting embodiment, and as illustrated in Figs. 4 and 7- 9, the overflow arrangement 60 includes a pipe portion 62 and one or more baffle portions 64. The embodiment of Fig. 7 includes one bell-shaped baffle portion 64, while the embodiment of Figs. 8 and 9 include two sloped, baffle portions 64. However, any number of baffle portions 64 may be utilized. The purpose of the baffle portions 64 is to prevent at least a portion of the solid waste material SW (whether floating or suspended) to flow into the overflow pipe portion 62 and allow the particulate material to settle from the liquid, as it rises to go over the outlet rim of the pipe portion 62. In particular, such an arrangement ensures that at least a portion of the suspended solids in the liquid waste material LW do not pass through the overflow pipe portion 62.

[0046] With specific reference to the embodiment of Figs. 8 and 9, the baffle portions 64 are specifically angled and configured for a transit application. In particular, these baffle portions 64 provide a configuration that allows the solid waste material SW to be baffled (or prevented from entry into the pipe portion 62) even when the apparatus 10 operates at a tilt of up to about 22.5° in any direction. Such a configuration is particularly useful in connection with moving vessels such as ships, train cars, buses, and the like. Of course, a single baffle portion 64 may be shaped and/or configured to achieve this result as well.

[0047] With continued reference to Figs. 8 and 9, an aeration sleeve 66 can be used to buffer external turbulence from a portion of the overflow arrangement 60. Therefore, in the embodiment of the apparatus 10 that utilizes a diffusion arrangement 54, this sleeve 66 can situated with respect to the pipe portion 62, and placed over the aeration zone, such that turbulence generated in the zone will be buffered from the outer quiescent zone in which the overflow pipe portion 62 is located. The wall of the sleeve 66 passes up and slightly above the fill line or waterline, so that the air can escape and aerate the open trickling zone above the recirculation basin 36. After passage through the overflow pipe portion 62, the treated effluent may pass over an optional chlorine dispenser unit and then through a contact chamber 68, in order to disinfect the effluent prior to discharge from the apparatus 10. However, any number of additional treatment units 23 or areas may be utilized to aid in the further treatment of the waste stream W. For example, the additional treatment units 23 may include a chlorine dispenser unit, a contact chamber 68, an ultraviolet unit, an ozone generator, a disinfection device, a further aerobic or anaerobic biological treatment unit, or any other conventionally known device to provide alternative means of disinfection or treatment.

[0048] It is further envisioned that the apparatus 10 can be heated so that it can operate on train cars and in other environments that are cold. Further, the apparatus 10 may act as a portable or permanent unit for pre-treatment or treatment of a wide variety of high-strength waste streams, particularly those that contain substantial organic solids. This would include portable toilet units, RV dump waste treatment systems, remote toilet facilities at parks or roadside rest areas, restaurant grease traps, or any other type of waste that would best be processed in this fashion.

[0049] As illustrated in box diagram form in Fig. 10, one preferred and non-limiting embodiment of a method 100 for the treatment of the waste stream W is provided. This method 100 includes: contacting at least a portion of the waste stream W with at least one of a plurality of bio-media members 18 to thereby at least partially separate solid waste material SW from liquid waste material LW; and recirculating at least a portion of the liquid waste material LW through the plurality of bio-media members 18. In addition, in the illustrated method, multiple additional treatment units 23 are used for the further treatment of the waste stream W prior to discharge.

[0050] In this manner, the present invention provides a portable waste treatment system that is designed for accelerated biological digestion of waste, such as toilet waste. The apparatus 10 and methods of the present invention may be used to treat human excrement within a closed vessel (housing 12) that receives direct discharge from a toilet or multiple toilets. The apparatus 10 utilizes mechanical maceration and separation of large solids from the incoming waste stream W through the use of bio-media members 18, which may include a coarsely woven bio-media screen (upper bio-media member 26) and progressively finer woven mesh (secondary bio-media members 28), which are bi-directional and waffle- patterned to provide excellent aeration of organic solids for rapid digestion. The apparatus 10 may also include multiple layers of thick, woven mat screens (secondary bio-media members 18) for final breakdown of solids to liquid, and uses recirculation of the liquid waste stream LW (together with any suspended or "non-separated" solid waste material SW, settled solid waste material SW, and/or in the form of a slurry or the like) that overflow the bio-media members 18 to re-activate bacteria and keep all layers moist and aerated. The apparatus 10 may further include selective siphoning-off of fully-processed effluent for further treatment or sterilization.

[0051] The bio-media members 18 may be designed to include a larger surface area and high aeration characteristics, so that bacterial decomposition of the waste stream W can occur at a high rate. As discussed, the one or more of the bio-media members 18 may also include intermeshed, coarse "waffle" patterns to aid in mechanical maceration of the deposited solid waste material SW. The diffusion arrangement 54, and specifically the perforated hose 56, may be specifically designed to ensure that a fine mist of aeration bubbles is continually dispersed in the recirculation basin 36.

[0052] As discussed, the bio-media members 18 can be graded with a rougher, more open texture and porosity in the upper bio-media members 18, and with smaller and finer texture and porosity in the lower bio-media members 18, thereby increasing the level of filtration of the liquid waste material LW as it passes down into the recirculation basin 36. Again, the bottom of the recirculation basin 36 may be sloped, such that settled solids are directed to the inlet portion of the passages 37 to the percolation pump 34. In this manner, these solids are recycled back over the bio-media members 18 for further filtration.

[0053] In a further preferred and non-limiting embodiment, additional bio-media members 18 may be arrayed in a vertical extension above the horizontal bio-media members, such that the discharge pipe 50 can be directed to a higher elevation for flow down over the vertical bio-media members 18 before impacting on the horizontal bio-media members 18, thereby expanding the fixed film surface area and acting as a further trickling filter. Such an arrangement is illustrated in schematic form in Fig. 1.

[0054] In this manner, the present invention provides an apparatus 10 and methods that allow for the effective treatment of a waste stream W from a waste source WS, such as a low-flow volume toilet that requires a minimum of excess water for treatment and disposal, The apparatus 10 and methods of the present invention provide enhanced biological digestion of the solid waste material SW components into liquid and gas end products, thus greatly reducing the biological oxygen demand (BOD) of the effluent discharge.

[0055] Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

What is claimed is:

1. An apparatus for the treatment of a waste stream, comprising:

a housing having an inner area;

a waste inlet configured to convey the waste stream to the inner area of the housing; a plurality of bio-media members positioned in the inner area of the housing and configured to contact at least a portion of the waste stream and at least partially separate solid waste material from liquid waste material;

a recirculation arrangement configured to convey at least a portion of the liquid waste material through or over the plurality of bio-media members; and

an effluent discharge configured to remove at least a portion of the liquid waste material.

2. The apparatus of claim 1, wherein the plurality of bio-media members are positioned and configured to retain at least a portion of the solid waste material thereon.

3. The apparatus of claim 1, wherein the plurality of bio-media members are at least partially in the form of at least one of the following: a woven mesh, a waffle-patterned layer, a fabric material, a screen material, a perforated material, a digestive material, a course material, a porous material, or any combination thereof.

4. The apparatus of claim 1, further comprising a porous packet of inoculum material positioned on at least one of the plurality of bio-media members.

5. The apparatus of claim 4, wherein the inoculum material is in the form of a culture of facultative bacteria.

6. The apparatus of claim 1, wherein the plurality of bio-media members are positioned and configured to permit at least a portion of the waste stream to cascade between a first bio-media member to at least one subsequent bio-media member.

7. The apparatus of claim 1, wherein the plurality of bio-media members are positioned and configured to permit at least a portion of liquid waste material to pass through at least one of the plurality of bio-media members.

8. The apparatus of claim I, further comprising a vent configured to facilitate the removal of air from the inner area of the housing.

9. The apparatus of claim 1, wherein the recirculation arrangement comprises a pump configured to convey at least a portion of the liquid waste material from a recirculation basin to an upper area of the housing for discharge towards the plurality of bio-media members.

10. The apparatus of claim 9, wherein the pump comprises a bell portion configured to receive air and a pipe having a first end positioned above a bottom of the bell portion and extending through a top of the bell portion, wherein at least a portion of the liquid waste material fills the pipe to a level equal with a fill line of the recirculation basin, and wherein, when air enters the bell portion, a bubble passes down and reaches the first end of the pipe, thereby urging a portion of the liquid waste material through the pipe for discharge.

11. The apparatus of claim 10, wherein the recirculation basin comprises sloped walls configured to facilitate the concentration of particles in the liquid waste material at a bottom area, wherein the pump is in fluid communication with at least a portion of the bottom area of the recirculation basin.

12. The apparatus of claim 9, further comprising a control device configured to control the delivery of air to the bell portion.

13. The apparatus of claim 1, further comprising a diffusion arrangement configured to aerate the liquid waste material in a circulation basin in the housing.

14. The apparatus of claim 1, further comprising an overflow arrangement configured to convey liquid waste material from a recirculation basin in the housing to the effluent discharge.

15. The apparatus of claim 14, wherein the overflow arrangement comprises an overflow pipe portion and a baffle portion, wherein the baffle portion comprises at least one baffle for preventing at least a portion of solid waste material from flowing into the overflow pipe portion.

16. The apparatus of claim 15, wherein the at least one baffle is configured to prevent at least a portion of solid waste material from flowing into the overflow pipe portion while the housing is tilted up to about 22.5° in any direction.

17. The apparatus of claim 14, wherein the overflow arrangement comprises an aeration sleeve configured to buffer external turbulence from a portion of the overflow arrangement.

18. The apparatus of claim 1, further comprising at least one additional treatment unit, wherein the at least one additional treatment unit comprises at least one of the following: a chlorine dispenser unit, a contact chamber, an ultraviolet unit, an ozone generator, a disinfection device, a further aerobic or anaerobic biological treatment unit, or any combination thereof.

19. A method for the treatment of a waste stream, comprising:

contacting at least a portion of the waste stream with at least one of a plurality of bio-media members to thereby at least partially separate solid waste material from liquid waste material; and

recirculating at least a portion of the liquid waste material through or over the plurality of bio-media members.

20. The method of claim 19, further comprising subjecting at least a portion of the separate solid waste material to aerobic digestion.