Anoxic system screen scour

Description

This application claims the benefit of U.S. Provisional Application No. 61/183,536, filed Jun. 2, 2009, the disclosure of which is expressly incorporated herein by reference.

SUMMARY

The problem is that the screen(s) used in current wastewater systems may be blinded by media, other solids or the biology growth on the screen(s) and that current methods of dislodging or discouraging the media, solids or biology growth may affect the oxygen levels beyond the proximity of the screen(s) is addressed by configuring the screen(s) and gas(es) introduced into the system to allow the gas(es) to at least partially contact the screen(s) to dislodge or discourage the media or solids from and/or biology growth on the screen(s) without substantially affecting the oxygen level in the proximity of the screen(s). Aspects of embodiments and embodiments of the present invention address these and other problems by providing, without limitation, methods, systems and/or kits.

Accordingly, some aspects of embodiments and embodiments of the present invention provide a method of dislodging or discouraging media from and/or biology growth on one or more screens in a wastewater system (e.g., an anoxic treatment system) by at least partially contacting one or more screens with one or more gases in such a way that the oxygen levels of the wastewater system in proximity to the one or more screens are substantially maintained at the same oxygen levels as when the one or more gases are not provided for at least partially contacting the one or more screens (hereinafter referred to as “Embodiment α”).

Some other aspects of embodiments and embodiments of the present invention provide a wastewater system including one or more screens and one or more means for providing one or more gases (hereinafter referred to as “Embodiment β”). In aspects, the means for providing the one or more gases is configured in such a way that the one or more gases at least partially contact the one or more screens. In other aspects, the oxygen levels of the wastewater system in proximity to the one or more screens are substantially maintained at the same oxygen levels as the oxygen levels present when the one or more gases are not provided for at least partially contacting the one or more screens. In yet other aspects, the means for providing the one or more gases is configured in such a way that the one or more gases at least partially contact the one or more screens and the oxygen levels of the wastewater system in proximity to the one or more screens are substantially maintained at the same oxygen levels as the oxygen levels present when the one or more gases are not provided for at least partially contacting the one or more screens.

Still other aspects of embodiments and embodiments of the present invention provide a kit for adapting a wastewater system, where the kit may include one or more screens, one or more means for providing one or more gases, and one or more means for interrelating the one or more screens and the one or more means for providing one or more gases such that the one or more gases will at least partially contact the one or more screens (hereinafter referred to as “Embodiment γ”). In aspects, the oxygen levels of the wastewater system in proximity to the one or more screens are substantially maintained at the same oxygen levels as the oxygen levels present when the one or more gases are not provided for at least partially contacting the one or more screens. In other aspects, the oxygen levels are substantially maintained at the same level as the oxygen levels present prior to installation of the kit. In yet other aspects, the oxygen levels of the wastewater system in proximity to the one or more screens are substantially maintained at the same oxygen levels as the oxygen levels present when the one or more gases are not provided for at least partially contacting the one or more screens and the oxygen levels are substantially maintained at the same level as the oxygen levels present prior to installation of the kit.

In Embodiments α, β, and γ, at least one of the one or more gases may be oxic. In aspects, the one or more gases comprise at least one gas including oxygen.

Embodiments α, β, and γ may further comprise one or more means for facilitating the movement of the one or more gases out of the wastewater system while substantially maintaining the oxygen levels of the wastewater system in proximity to the one or more screens at the same oxygen levels as when the one or more gases are not provided for at least partially contacting the one or more screens. In aspects, the one or more means for facilitating the movement of the one or more gases out of the wastewater system may comprise one or more gas conduits through which the one or more gases are provided to the system. In other aspects, the one or more screens may be configured in relation to the one or more gas conduits such that the longest axis of the one or more screens is in a substantially perpendicular orientation and the shortest axis of the one or more screens is in a substantially parallel orientation. In addition to or separate from the above aspects, the one or more means for facilitating the movement of the one or more gases out of the wastewater system may comprise one or more vents wherein the one or more vents may be configured so as to allow at least a portion of the one or more gases to exit the wastewater system in proximity to the one or more screens.

In Embodiments α, β, and γ, the one or more gases may be provided in such a way as to allow the one or more gases to at least partially contact the one or more screens in such a way as to dislodge or discourage media or biology growth from adhering to the one or more screens.

In Embodiments α, β, and γ, the wastewater system may be configured to maintain the denitrification process of the wastewater system in proximity to the one or more screens. In Embodiments α, β, and γ, the wastewater system may be configured not to stop the denitrification process of the wastewater system in proximity to the one or more screens.

In aspects of Embodiments α, β, and γ, “proximity” refers to that area of the wastewater system greater than the width x of the screen assembly screen. Those having skill in the art will appreciate that x may be about a foot or less. In other aspects, proximity may be as little as five inches or less. In still other aspects, proximity may be as little as three inches or less. In further aspects, proximity may be as little as one inch or less. Those having skill in the art will appreciate that the proximity will be such that the purpose of the invention is preserved.

In Embodiments β and γ, the one or more screens and the one or more means for providing the one or more gases may be configured in such a way that at least a portion of the one or more gases pass through the one or more screens. In Embodiments β and γ, the one or more screens may be arcuate. In Embodiments β and γ, the one or more means for providing one or more gases may comprise one or more gas conduits.

In Embodiment α, the one or more gases may be provided using a gas conduit.

In Embodiments α, β, and γ, the wastewater system may include a basin. In aspects, the basin may include anoxic liquor, one or more inlets, one or more outlets, and one or more means for providing one or more gases to one or more screens (e.g., anoxic system screen scours). In other aspects, the one or more anoxic system screen scours may be located adjacent to the wall of the basin at the outlet. In further aspects, the anoxic system screen scour may include one or more screen assemblies. In other aspects, the anoxic system screen scour may further include one or more areas of solid material. In other aspects, the one or more screen assemblies may include one or more screens and one or more gas conduits. In aspects, the one or more gas conduits may be configured in such a way as to allow one or more gases to at least partially contact the one or more screens. In other aspects, the one or more gas conduits may be configured to allow the one or more gases to pass through the one or more screens and substantially through the outlet. In further aspects, the one or more gases may contact the one or more screens in such a way as to dislodge or discourage biology growth on the one or more screens; and wherein the anoxic character of the anoxic liquor is substantially maintained. In other aspects, the system may further include media. In further aspects, the one or more gases may contact the one or more screens in such a way as to dislodge or discourage media from the one or more screens; and wherein the anoxic character of the anoxic liquor is substantially maintained. In aspects, the outlet may be smaller than the screen assembly. In yet other aspects, the one or more screens may be sized to substantially prevent the media from exiting the system. In addition to or separately from the above other aspects, the one or more screens may be configured in such a way as to facilitate the at least partial contact of the one or more gases with the one or more screens. In other aspects, the one or more screens may be configured in relation to the gas conduit such that the longest axis of the screen is in a substantially perpendicular orientation and the shortest axis of the screen is in a substantially parallel orientation. In aspects, the bottom of the screen assembly may be narrower than the top of the screen assembly.

Numerous other aspects of embodiments, embodiments, features, and advantages of the present invention will appear from the above description and the accompanying drawings. In that description and/or the accompanying drawings, reference is made to exemplary aspects of embodiments and/or embodiments of the invention which can be applied individually or combined in any way with each other. Such aspects of embodiments and/or embodiments do not represent the full scope of the invention. In the interest of brevity and conciseness, any ranges of values set forth in this specification contemplate all values within the range and are to be construed as support for claims reciting any sub-ranges having endpoints which are real number values within the specified range in question. By way of a hypothetical illustrative example, a disclosure in this specification of a range of from 1 to 5 shall be considered to support claims to any of the following ranges: 1-5; 1-4; 1-3; 1-2; 2-5; 2-4; 2-3; 3-5; 3-4; and 4-5. Also in the interest of brevity and conciseness, it is to be understood that such terms as “is,” “are,” “includes,” “having,” “comprises,” and the like are words of convenience and are not to be construed as limiting terms and yet may encompass the terms “comprises,” “consists essentially of,” “consists of,” and the like as is appropriate.

These and other aspects, advantages, and salient features of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings referenced herein form a part of the specification. Features shown in the drawings are meant to be illustrative of some, but not all, embodiments of the invention, unless otherwise explicitly indicated, and implications to the contrary are otherwise not to be made. Although like reference numerals correspond to similar, though not necessarily identical, components and/or features in the drawings, for the sake of brevity, reference numerals or features having a previously described function may not necessarily be described in connection with other drawings in which such components and/or features appear.

FIG. 1 is a schematic of a wastewater system (e.g., an anoxic treatment system) according to aspects of embodiments of the present invention;

FIG. 2 is a perspective cut-away view of one or more means for providing one or more gases to one or more screens (e.g., an anoxic system screen scour) made in accordance with aspects of embodiments of the present invention;

FIG. 3A is a cross section of one or more means for providing one or more gases to one or more screens (e.g., an anoxic system screen scour) made in accordance with aspects of embodiments of the present invention;

FIG. 3B is a cross section of one or more means for providing one or more gases to one or more screens (e.g., an anoxic system screen scour) made in accordance with aspects of embodiments of the present invention;

FIG. 4 is a perspective view of one or more means for providing one or more gases to one or more screens (e.g., an anoxic system screen scour) made in accordance with aspects of embodiments of the present invention;

FIG. 5A is a cross-sectional or end view of a media according to aspects of embodiments of the present invention;

FIG. 5B is a cross-sectional or end view of a media according to aspects of embodiments of the present invention; and

FIG. 5C is a cross-sectional or end view of a media according to aspects of embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of exemplary aspects of embodiments and embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific aspects of embodiments and embodiments in which the invention may be practiced. While these aspects of embodiments and embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended. Alterations and further modifications of the features illustrated herein, and additional applications of the principles illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of this disclosure. Specifically, other aspects of embodiments and embodiments may be utilized, logical changes (e.g., without limitation, any one or more of chemical, compositional (e.g., without limitation, any one or more of chemicals, materials, . . . and the like), electrical, electrochemical, electromechanical, electro-optical, mechanical, optical, physical, physiochemical, . . . and the like) and other changes may be made without departing from the spirit or scope of the present invention. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of aspects of embodiments and embodiments of the present invention are defined by the appended claims. It is also understood that terms such as “top,” “bottom,” “outward,” “inward,” and the like are words of convenience and are not to be construed as limiting terms.

FIG. 1 shows a wastewater system (e.g., an anoxic treatment system 10) having a basin 12 including an inlet 14 and an outlet 16 as well as optional elements. The basin 12 may contain a liquor 20 during treatment. The basin 12 may contain one or more means for providing one or more gases to one or more screens (e.g., an anoxic system screen scour(s) 22) that may include one or more screen assembly(ies) 23 and one or more oxygen-containing gas conduit(s) 26. The anoxic system screen scour 22 may be completely submerged below the liquor level 19 or partially submerged below the liquor level 19. The anoxic treatment system 10 may also contain one or more media 28 or types of media 28. The anoxic system screen scour 22 may be located adjacent to the wall 18 of the basin 12 at the outlet 16.

According to aspects of embodiments of the present invention, the anoxic system screen scour 22 may be configured in such a way so as to allow one or more oxic gases to be provided by the one or more oxygen-containing gas conduit(s) 26 to the screen assembly 23 in such a manner that the oxic gas will dislodge or discourage media 28 from adhering to the screen assembly screens 24, 30, 32, 34 and/or will dislodge or discourage biology growth on the screen assembly screens 24, 30, 32, 34, thereby preventing or discouraging the blinding of the screen(s) while at the same time substantially maintaining the anoxic character of the liquor 20.

An aspect of an embodiment of an anoxic system screen scour 22 is shown in FIG. 2. The anoxic system screen scour 22 may be located adjacent to the wall 18. The outlet 16 may be located in the wall 18 through which the effluent may flow. The anoxic system screen scour 22 may include screens 24, 32, 30, 34 so as to create a permeable barrier around outlet 16. The oxygen-containing gas conduit 26 may be located in relation to the screen assembly in such a way that the oxic gas may dislodge or discourage media 28 from adhering to the screen assembly screens 24, 30, 32, 34 and/or dislodge or discourage biology growth on the screen assembly screens 24, 30, 32, 34, thereby preventing or discouraging the blinding of the screen(s) while at the same time substantially maintaining the anoxic character of the liquor 20. For example, as shown in FIG. 2, a oxygen-containing gas conduit 26 may be located substantially near or at the bottom 30 of the screen assembly screen 24. The oxygen-containing gas conduit 26 may be in communication with a gas supply, not shown, via pump line 40, pump 42, gas source line 44, and/or other lines or systems, not shown, for moving the gas.

FIG. 3A shows other aspects of embodiments concerning the relationship of various dimensions of an anoxic system screen scour 22, such that the relationship of various dimensions facilitate the oxic gas dislodging or discouraging media 28 from adhering to the screen assembly screens 24, 30, 32, 34 and/or dislodging or discouraging biology growth on the screen assembly screens 24, 30, 32, 34, thereby preventing or discouraging the blinding of the screen(s) while at the same time substantially maintaining the anoxic character of the liquor 20.

Examples include, without limitation: the spacing of the oxygen-containing gas conduits 26, 26′, 26″ in relation to each other as well as the screen assembly 23; a vertical inclination angle Θ of screen assembly screen 24 may be equal to or greater than about 0° and less than about 90°; a height h_s of the screen assembly 23 is greater than or substantially equal to a height h_o of the outlet 16; a width y of the oxygen-containing gas conduit 26, 26′, 26″ may be less than a width x of the screen assembly screen 34 or less than the difference of width x of the screen assembly screen 34 and a width z of the screen assembly screen 30; a width z of the screen assembly screen 30 is greater than or substantially equal to 0; or combinations thereof. A anoxic system screen scour 22 may optionally include a vent 36 located on side 32 extending upwards so that the oxic gas does not substantially influence the anoxic character of the liquor 20.

FIG. 3B shows other aspects of embodiments, such as, without limitation, screen assembly screen 24 being concave; vent 36 located on top 34 extending upwards so that the oxic gas does not substantially influence the anoxic character of the liquor 20; top 34 being configured to encourage the movement of the oxic gas through vent 36; outlet 16 being smaller than the screen assembly 23; additional or alternative oxygen-containing gas conduit 26′ located below the screen assembly screen 30; or combinations thereof.

FIG. 4 shows other aspects of embodiments, such as, without limitation, a width z of bottom 30 being substantially 0; multiple vents 36 extending upwards from the side 32 and top 34 so that the oxic gas does not substantially influence the anoxic character of the liquor 20; or combinations thereof.

It will be appreciated that one or more oxygen-containing gas conduit(s) 26 may be located in relation to screen assembly 23 in any way or combination such that the oxic gas may be used to dislodge or discourage media 28 from adhering to the screen assembly screens 24, 30, 32, 34 and/or to dislodge or discourage biology growth on the screen assembly screens 24, 30, 32, 34, thereby preventing or discouraging the blinding of the screen(s) while at the same time substantially maintaining the anoxic character of the liquor 20.

In many wastewater treatment systems, such as anoxic treatment system 10, the goal is to remove all forms of nitrogen. In such systems, the influent nitrogen passing through inlet 14 is largely in the form of ammonia. In aspects of embodiments of such systems, this ammonia (NH₃) is reduced under aerobic conditions to NO₂ and NO₃ (collectively referred to as NO_x) in a process commonly called nitrification. According to aspects of embodiments of anoxic treatment system 10, the nitrogen is further reduced by converting NO_x to N₂ in very low levels. This process is commonly called denitrification. Denitrification may be completed under anoxic conditions where there may be an absence of oxygen and biology which has been selected specifically to utilize the electron donor found in NO_x may be present. Anoxic treatment system 10 may be subsequent to an aerobic stage, or may be prior to an oxic stage. In the anoxic treatment system 10, the nitrified mixed liquor 20 from an oxic zone may be recycled to the head of the anoxic treatment system 10.

As the metabolic reactions using oxygen are more efficient and because the biology capable of using NO_x in the absence of oxygen prefers oxygen when it is present, even in small amounts, the denitrification process will be retarded and oxic metabolisms will occur when small amounts of oxygen are present.

In some aspects of embodiments, the addition of attached growth media 28 in the anoxic treatment system 10 is used to enhance the presence and effectiveness of the denitrification biology. In these aspects of embodiments, a screen assembly 23 is used to contain the media 28 within the anoxic basin 12. Even when media 28 is not used, screen assemblies 23 may be used to inhibit the passage of solids from the basin 12 with the effluent through outlet 16. One common problem with these screen assemblies 23 is that the media 28 may adhere to and biology may grow on the screen assembly screens 24, 30, 32, 34, thereby blinding the screen(s). Aspects of embodiments of the present invention may be used to dislodge or discourage media 28 from adhering to the screen assembly screens 24, 30, 32, 34 and to dislodge or discourage biology growth on the screen assembly screens 24, 30, 32, 34, thereby preventing or discouraging the blinding of the screen(s).

Applicant contemplates that in aspects of embodiments of the present invention, an anoxic treatment system 10 may be used in or be any one of a municipal wastewater treatment facility, an industrial wastewater treatment facility, a commercial wastewater treatment facility, a ship wastewater treatment facility, an agricultural wastewater treatment facility, or any combination of any of the preceding. Descriptions of wastewater treatment systems applicable to the current invention can be found in U.S. Publication No. 2007/0102354 and U.S. Pat. No. 7,445,715, both of which are hereby fully incorporated by reference.

In operation, an influent is provided through inlet 14 so that liquor 20 is contained within basin 12. An effluent leaving basin 12 of the anoxic treatment system 10 does so by outlet 16. The anoxic treatment system 10 may contain numerous media 28 and types of media 28 to support biological growth. In situations where there is a screen assembly 23 at outlet 16, the media 28 may adhere to and/or biology may grow on the screen assembly screens 24, 30, 32, 34, thereby blinding the screen(s). The anoxic system screen scour 22 may be able to use a gas which, if introduced into an anoxic environment, would slow or stop the denitrification process taking place in liquor 20, may be used to dislodge or discourage media 28 from adhering to the screen assembly screens 24, 30, 32, 34 and/or to dislodge or discourage biology growth on the screen assembly screens 24, 30, 32, 34, thereby preventing or discouraging the blinding of the screen(s) while at the same time substantially maintaining the anoxic character of the liquor 20. The oxygen-containing gas moves from the oxygen-containing gas conduit 26 upwards to make contact with the screen assembly 23. The oxygen-containing gas may exit basin 12 through the outlet 16 with the effluent, or optionally it may exit from the anoxic system screen scour 22 via the vent 36 extending upwards from the anoxic system screen scour 22.

In an anoxic treatment system 10 containing one or more media 28, the screen assembly screens 24, 30, 32, 34 are contemplated to be sized so as to facilitate retention of the number of media 28 within the anoxic treatment system 10 and, optionally, to prevent the passage of solids from the basin 12 through the outlet 16. The screen assembly screens 24, 30, 32, 34 may be sized with screen slots smaller than the smallest dimensions of the one or more media 28. In an anoxic treatment system 10 which does not contain media 28, the screen assembly screens 24, 30, 32, 34 may be sized with screen slots in any size which would facilitate the retention of any solids within the liquor 20.

The screens used in the screen assembly 23 may be configured to allow the passage of the oxic gas released from the oxygen-containing gas conduit 26 substantially pass through the screen assembly 23 into the interior of the anoxic system screen scour 22 with minimal gas passing into liquor 20 within basin 12. An example of a screen orientation which may allow the passage of the gas released from the oxygen-containing gas conduit 26 substantially pass through the screen assembly 23 into the interior of the anoxic system screen scour 22 with minimal gas passing into liquor 20 within basin 12 is an orientation such that the longest axis of the screen slot, the space between the material which makes up the screen, is in a substantially perpendicular orientation and the shortest axis is in a substantially parallel orientation in relation to the oxygen-containing gas conduit 26.

The Applicants contemplate that examples of such screens would include, without limitation, grating, expanded metal, hexagonal netting, perforated mesh, square mesh, wedge wire screen, welded wire mesh, wire mesh fence, woven, other screens known to one having ordinary skill in the art, or any combination thereof. Such screens may be made of any type of material adapted to withstand a wastewater treatment system, specifically an anoxic wastewater treatment system, without degrading and/or corroding substantially. Examples include metallic materials such as stainless steels, durimet alloys, titanium, titanium alloys, or other metals known to one skilled in the art; polymers including without limitation, polyvinyls such as polyvinyl chloride, polyolefins such as polyethylene and/or polypropylene, fluoropolymers such as polyvinylidene fluoride or polytetrafluoroethylene (PTFE), or other polymers known to one skilled in the art; any other material adapted to withstand a wastewater treatment system, specifically an anoxic wastewater treatment system, without degrading and/or corroding substantially known to one skilled in the art; a composite of at least two of the preceding; or any combination of any of the preceding.

Portions of screen assembly 23 could also be made of a solid material through which liquor 20 would not be able to pass. For example, it is contemplated that screen assembly bottom 30 may be a solid material disclosed above extending from screen assembly screen 24 and to wall 18 as shown in FIG. 2. Likewise, screen assembly side 32, screen assembly top 34, or any combination thereof may be a solid material disclosed above extending from screen assembly screen 24 to wall 18.

Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by an aspect of an embodiment and/or embodiments of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

The functions of the various elements shown in the Figures would, in aspects of embodiments and/or embodiments be implemented by one or more screens (e.g., grating, expanded metal, hexagonal netting, perforated mesh, square mesh, wedge wire screen, welded wire mesh, wire mesh fence, woven, . . . etc.), conduits (e.g., pipes, tubing, manifolds, . . . etc.), interrelating elements (e.g., fasteners, hardware, braces, supports, connectors, suspenders, spacers, . . . etc.) or the like rather than individual elements. Thus, in the claims hereof any element or combinations of elements expressed as or including a means for performing a specified function or functions is intended to encompass any way of performing that function and combinations of any way of performing that function. Thus, it will be appreciated that Applicants regard any element or elements capable of performing particular functions recited in the claims as being equivalent to those disclosed herein.

While typical aspects of embodiment and/or embodiments have been set forth for the purpose of illustration, the foregoing description and the accompanying drawings should not be deemed to be a limitation on the scope of the invention. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of aspects of embodiments of the present invention. Numerous other aspects of embodiments, embodiments, features, and advantages of the present invention will appear from the description and the accompanying drawings. In the description and/or the accompanying drawings, reference is made to exemplary aspects of embodiments and/or embodiments of the invention, which can be applied individually or combined in any way with each other.