Tricking filter system and method

Abstract

A trickling filter for treating wastewater and producing a treated effluent includes a tank having an internal volume; a filter medium mounted in the tank; a support beam supporting the filter media in the tank between the top surface of the filter media and the base of the tank, without ventilation openings or in a sealable manner; a reservoir defined between the support beam and the base of the tank; and an extension wall extending above the top surface to block wind relative to the top surface.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 528,722, filed July 25, 2023, entitled “Trickle Filter System and Method,” the entire contents of which are incorporated herein by reference. Background Technology

[0002] Trickling filter systems are designed to treat wastewater by exposing it to a layer of microbial slime grown on a media bed. Trickling filter systems are designed to treat domestic sewage and industrial wastewater alone or in combination. Some trickling filter systems used in conjunction with sewer systems treat a combination of stormwater runoff and domestic and / or industrial wastewater. Trickling filter systems are designed to remove organic pollutants and ammonia nitrogen from wastewater streams through aerobic treatment by microorganisms in the slime layer within the bed of the trickling filter tank.

[0003] Existing trickling filter systems often become limited when ambient and wastewater temperatures are low because the temperature of the wastewater in the trickling filter tank drives the biological processes used to treat the wastewater, and these processes are weakened at relatively low temperatures. This effect can be particularly pronounced in regions that frequently experience cold temperatures, and the efficiency of trickling filter systems can be negatively impacted during winter. Limited air or oxygen levels in the wastewater also reduce the efficiency of trickling filter systems, decreasing the effectiveness of the biological processes used to treat the wastewater. It is desirable to design, construct, and implement a trickling filter system that maintains the desired temperature and oxygen levels or aeration within the trickling filter tank to sustain effective biological processes during wastewater treatment and thus treat wastewater more efficiently. Summary of the Invention

[0004] In short, preferred embodiments of the invention relate to a trickling filter system for treating wastewater and producing treated effluent. The trickling filter system includes: a tank having an internal volume; a filter media bed having a support beam supporting the filter media in the tank between a top surface of the filter media and a base of the tank; a storage tank defined between the support beam and the base of the tank; and an extending wall extending above the top surface to block airflow relative to the top surface. Wastewater is introduced into the top of the media bed via a distribution system, which may be a rotating distribution arm for a circular tank, a fixed nozzle distribution for a rectangular tank, or a distribution system for tanks with shapes other than circular and rectangular. The wastewater then drips through the media bed, where the contaminated wastewater comes into contact with microorganisms in a slime layer and ambient air, causing the wastewater to undergo a biochemical treatment process. The treated wastewater is then collected at the bottom of the storage tank and discharged from the tank to a downstream treatment unit or otherwise discharged from the tank. The treated wastewater may alternatively be recycled back to the distribution system for further treatment via the media bed.

[0005] In another aspect, a preferred invention relates to a trickling filter system for treating wastewater and producing treated effluent. The trickling filter includes: a tank having an internal volume; a filter medium housed within the tank; a support beam supporting the filter medium between a top surface of the filter medium and a bottom of the tank; a storage tank defined between the support beam and the bottom of the tank; and an extension wall extending above the top surface, the extension wall being configured to block airflow relative to the top surface.

[0006] In another aspect, a preferred invention relates to a trickling filter system for treating wastewater and producing treated effluent. The trickling filter includes: a tank having an internal volume and defining a tank height; filter media installed in the tank; a support beam supporting the filter media in the tank; a storage tank defined between the support beam and the base of the tank; a distributor configured to introduce wastewater onto a top surface; and an extending wall extending above the top surface and defining a gap height. The filter media includes the top surface and defines a media bed depth. A bottom drain height is defined between the bottom of the tank and the support beam. The media bed depth is approximately 85% to 143% of the bottom drain height. Attached Figure Description

[0007] The foregoing overview and the following detailed description of preferred embodiments of the trickling filter system of this application will be better understood when read in conjunction with the accompanying drawings. Preferred embodiments are shown in the drawings for illustrative purposes of the trickling filter system and method. However, it should be understood that this application is not limited to the precise arrangement and tools shown. In the drawings: Figure 1 The illustration shows a top perspective partial cross-sectional view of a trickling filter system according to a preferred embodiment of the present invention. Detailed Implementation

[0008] The use of certain terms in the following description is for convenience only and not for limitation. Unless otherwise specified herein, the terms “a” and “described” are not limited to a single element but should be understood as “at least one.” The words “right,” “left,” “lower,” and “upper” indicate directions in the referenced figures. The terms “inward” or “farward” and “outward” or “nearward” refer to directions toward and away from components of the trickling filter system, or preferably, the geometric center of the trickling filter system and its associated components. Terms include those listed above, their derivatives, and words with similar meanings.

[0009] It should also be understood that the terms “about,” “approximately,” “generally,” “substantially,” and similar terms used herein when referring to the specifications or features of components of this preferred invention indicate that the described specifications / features are not strict boundaries or parameters and do not exclude minor variations that are functionally identical or similar, as would be understood by one of ordinary skill in the art. At a minimum, such references including numerical parameters will include variations using mathematical and industry principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.) that do not change the least significant digit.

[0010] refer to Figure 1 A high-speed nitrification trickling filter or trickling filter system (generally designated 9) with enhanced passive aeration and natural heating (biothermal heating) includes: a trickling filter tank 1 containing filter media 2; a support beam or media support beam 3 supporting the filter media 2; a support column 4 supporting the support beam 3; and a distributor 5, which may consist of a rotating distribution arm or a speed-controlled distributor arm 5, for introducing wastewater into the tank 1. The support beam 3 supports the filter media 2 in the tank 1 between the top surface 2c of the filter media 2 and the bottom 1b of the tank 1. The tank 1 has an internal volume to hold the components of the trickling filter system 9 and for filtering the wastewater therein, which typically flows from the top 1a of the tank 1 through the distributor 5 to the bottom 1b of the tank 1. The tank 1 defines a longitudinal axis 14, which preferably extends vertically from the top 1a of the tank 1 to the bottom 1b of the tank 1. Wastewater typically flows from distributor 5 along longitudinal axis 14 to bottom 1b of tank 1 under gravity, but wastewater can flow in other directions within tank 1, especially under the influence of filter media 2.

[0011] Filter media 2 is installed in tank 1, located between top 1a and bottom 1b. Wastewater is exposed to a layer of microbial slime growing on filter media 2 for wastewater treatment. Preferred filter media 2 may comprise a combination of cross-flow media 2a and vertical flow media 2b, including two or three layers of cross-flow media 2a positioned above layers of vertical flow media 2b. The trickling filter system 9 is not limited to specific design requirements, designer preferences, and other factors. Figure 1 This first preferred arrangement of the filter media 2 shown can include alternative arrangements and numbers of layers of filter media 2a, 2b, 2. For example, filter media 2 can consist entirely of transverse flow media 2a, entirely of vertical flow media 2b, or composed of different... Figure 1 The filter media 2 shown is composed of a combination of a transverse flow filter media 2a and a vertical flow filter media 2b. The transverse flow media 2a is configured to cause wastewater to flow at an angle relative to the longitudinal axis 14, and the vertical flow filter media 2b is configured to cause or allow wastewater to flow generally parallel to the longitudinal axis 14. The transverse flow media 2a and the vertical flow media 2b may include surface features (e.g., roughness or microstructure) to maximize surface area, create a uniform liquid distribution, allow air circulation, and provide drainage for biomass. The transverse flow media 2a and the vertical flow media 2b are preferably composed of sheets assembled into packs, which can be stacked in a tank on a support beam 3. The filter media 2, 2a, 2b, when both transverse flow media 2a and vertical flow media 2b are configured to cause wastewater to flow in a combination that is at an angle to the longitudinal axis and generally parallel to the longitudinal axis 14. This angle is preferably thirty to sixty degrees (30-60°), and can be forty-five degrees (45°). Wastewater can flow through the filter media 2 in tank 1 in the following directions: in a transverse flow direction, in a vertical flow direction, or in a combination of directions, thereby exposing it to the filter media 2 and the bacteria or slime growing on the filter media 2.

[0012] The treated wastewater is filtered into a storage tank 6 below the support beam 3 and flows out of tank 1 through a discharge channel or effluent trough 7 for further treatment or discharge. The storage tank 6 is defined between the support beam 3 and the bottom 1b of tank 1. In the wastewater flow, an effluent pipe 10 is located downstream of the storage tank 6. The effluent is partially or fully treated wastewater or other liquid flowing out of the storage tank 6. The inflow is wastewater or other liquid flowing into the trickling filter system 9.

[0013] Tank 1 has an internal volume and a defined tank height H T The preferred tank 1 includes an extended wall 8 that extends above the top surface 2c of the filter medium 2, preferably with a gap height or extended wall height H. C At least 6 feet (6 ft) or 1.83 meters (1.83 m) above the top surface 2c of filter media 2 to reduce heat loss from wastewater, but the gap height H C It is not limited to this. Gap height H CAlmost any specification can be used to extend above the top of the filter medium 2 to limit heat loss in the trickling filter system 9 due to wind or convective heat loss. The trickling filter system 9 is also configured to promote air circulation through the filter medium 2 and improve oxygen transfer, thereby increasing the biofilm treatment capacity. An extended wall 8 is provided to block wind, as the extended wall 8 blocks or reduces air movement at the top surface 2c of the filter medium 2 and near the distributor 5, to limit or reduce forced conduction between air and wastewater during use. As a non-limiting example, the gap height H... C It can be approximately six feet (6 ft) or 1.83 meters (1.83 m), and the tank height H T It could be about twenty feet (20 ft) or six point 10 meters (6.10 m).

[0014] The innovative nitrification filter or preferred trickling filter system 9 also preferably includes an elevated bottom drain / media support system, comprising a support beam 3, a support column 4, a storage tank 6, a shallow media bed 2, and a velocity control distribution arm 5, which can consistently maintain an ammonia nitrogen concentration of 1.5 mg / L or lower in the trickling filter effluent pipe 10 from the trickling filter system 9 when the filter influent temperature is less than 45°F or about 7.22°C. The bottom drain / media support system is positioned within the storage tank or bottom drain space 6 below the media support beam 3 and above the base of the tank 1. In this preferred trickling filter system 9, the bottom drain / media support system, including the support beam 3, column 4, and storage tank 6, has a bottom drain height H. U Within the range of five to seven feet (5-7 ft) or 1.52 to 2.13 meters (1.52-2.13 m), and the filter media 2 has a media bed depth H M Approximately the height H of the bottom drainage section U The percentage is 85% to 143% (85%-143%). In a preferred embodiment, the media bed depth H M Approximately four to ten feet (4-10 ft) or 1.22 to 3.05 meters (1.22-3.05 m). Bottom drainage section height H U It can assist in air circulation in wastewater and increase the treatment capacity of biofilm. The preferred bottom drainage section height H... U The depth of the medium bed is approximately five to seven feet (5-7 ft) or 1.52 to 2.13 meters (1.52-2.13 m), and the medium bed depth H M Preferably, it is approximately the height H of the bottom drainage section. U 85% to 143% (0.85 XH) U – 1.43 XH UWithin the range of ), this preferred design allows for improved air circulation through the media bed 2. Bottom drain height H U Preferably, it is confined between the bottom 1b of the tank 1 and the support beam 3. The media depth Hm can be defined by the filter media 2. The ratio of the media depth Hm to the bottom drainage height Hu can be 85% to 143%. A preferred trickling filter system 9 has: a relatively shallow filter media 2, and a media bed depth Hm. M Approximately six to ten feet (6-10 ft) or 1.83 to 3.05 meters (1.83-3.05 m); with a relatively high bottom drainage section, wherein the bottom drainage section height H U Approximately five to seven feet (5-7 ft) or 1.52 to 2.13 meters (1.52-2.13 m); and a relatively high clearance height H. C It is approximately six feet (6 ft) or 1.83 meters (1.83 m) high, because many existing trickling filter systems do not extend the wall height above the filter media, or only have a limited wall height extending above the filter media.

[0015] In a preferred embodiment, the media bed depth H M Height H of bottom drainage section U The ratio is between 85% and 143%. This ratio is configured to increase passive aeration capacity and improve the aerobic treatment performance of the trickling filter system 9. The media bed depth H... M Height H of bottom drainage section U The ratio is designed to promote the exposure of wastewater to filter media 2 and aeration in storage tank 6.

[0016] Filter media 2 is preferably composed of a sheet constructed from a filler sheet material composed of a polymeric material. The polymeric material of the filler sheet material is preferably composed of polyvinyl chloride (“PVC”), polypropylene (“PP”), polyethylene (“PE”), or other synthetic materials. This includes structured sheets of media 2, filler packages or components of structured sheet media 2, or other synthetic media installed to provide surfaces or areas for bacterial growth and maintenance of biochemical reactions. Filter media 2 may alternatively consist of a non-self-supporting random medium that promotes the growth of slime or bacteria and the flow of wastewater through it. The biochemical reaction converts ammonia nitrogen in the wastewater into nitrate nitrogen. Filter media 2 may also consist of random media or other self-supporting media (e.g., mesh-structured media) without significantly affecting the design, configuration, and / or function of the preferred trickling filter system 9. A first preferred embodiment of filter media 2 consists of a self-supporting media bed. Filter media 2 may consist of a self-supporting media bed other than structured sheets of synthetic materials (e.g., hair-curled mesh-structured media).

[0017] The bottom drain container can be completely enclosed within the tank 1 without any ventilation openings, or it can have ventilation openings or vent ports 11 that can be completely sealed to reduce airflow circulation through the openings or vent ports 11. Accordingly, the tank 1 may exclude any ventilation openings (e.g., vent ports 11) near or anywhere within the support beam 3. Thus, the tank 1 is configured to improve airflow circulation through open channels in the filter medium 2 and to promote the biochemical reactions of the wastewater flowing through the filter medium 2. In a preferred embodiment, the tank 1 includes a selectively sealable vent port 11 located on the side of the tank 1 near the support beam 3, which is selectively sealable to allow or prevent the wastewater from being exposed to ambient air. The sealable vent port 11 preferably captures and retains biothermal processes within the wastewater in the tank 1 and retains heat from warmer wastewater flows or from exothermic reactions within the tank 1. A control box 13 with a gate valve can be connected to the trickling filter effluent conduit 10 to control the flow of treated effluent from the storage tank 6. The trickling filter system 9 may include a vent 11 located in the tank 1, which opens to the storage tank 6. Heat from the residue (described in more detail below) can be configured to warm the ambient air flowing into the storage tank 6. The tank 1 may also include the vent 11 to increase airflow into the storage tank, which can facilitate chemical reactions within the tank. The vent 11 can be closed during operation (particularly in cold conditions or cold climates) to prevent cold air from affecting the chemical reactions within the tank 1 and to maintain the temperature within the tank 1.

[0018] The design is characterized by a combination of an extended wall 8 and a shallow media bed or filter media 2, and a tall bottom drain / media support system. This promotes air circulation through the filter media 2 and thus increases oxygen transfer to the wastewater trickling through the filter media 2, thereby improving the performance of the preferred trickling filter system 9 described herein. The enclosed bottom drain container reduces the possibility of air short-circuiting through vent openings or vent ports 11, which can occur in conventional trickling filters with bottom drain openings or vent ports. The enclosed bottom drain container also limits contact or exposure between the wastewater / bacteria and the cold ambient air outside the trickling filter system 9. Limiting the exposure of wastewater and bacteria on the filter media 2 to the cold ambient air reduces heat loss, which can negatively impact the biochemical treatment processes occurring in the preferred trickling filter system 9.

[0019] Therefore, the dissolved oxygen (“DO”) concentration in the effluent conduit 10 of the preferred trickling filter system 9 is higher than that in the effluent of a conventional trickling filter. It has been observed that the DO concentration in the effluent conduit 10 of the preferred trickling filter system 9 is close to saturation or supersaturation.

[0020] Previous studies have shown that ammonia nitrogen removal is a function of total liquid DO in submerged biofilm reactors (Rusten et al., 2006). Higher DO concentrations lead to higher nitrification rates as ammonia nitrogen is removed from wastewater via oxidation processes (i.e., nitrification).

[0021] This preferred design of the trickling filter system 9 is further characterized by the prevention of heat loss and natural heating effects, which reduces the impact of relatively low wastewater temperatures or relatively low ambient temperatures on nitrification activity in the trickling filter system 9. The nitrification rate decreases with decreasing temperature and may cease when the wastewater temperature is below 41 degrees Fahrenheit (41°F) or approximately 5 degrees Celsius (5°C). In this preferred design of the trickling filter system 9, heat loss through the ventilation openings 11 is reduced, at least in part because the bottom drain space or storage tank 6 is enclosed. The heat generated by biological activity in the area of ​​the filter media 2 can be retained in the large, enclosed bottom drain space 6 and used to warm the cold wastewater and air entering from the distributor arm 5 or other wastewater introduction systems or equipment. High levels of nitrification have been observed to occur at ambient temperatures as low as -2°F (-2℉) or approximately -18.9°C (-18.9 °C), and at a gap height H of approximately six feet (6 ft) or 1.83 meters (1.83 m) above, for example, the top surface 12 of the medium 2. C At the same time, the heat retained in the bottom drainage space 6 improves the high nitrification rate of wastewater in the area of ​​filter media 2.

[0022] Another feature of this preferred trickling filter system 9 in preventing heat loss is the extended wall 8, which serves as an airflow barrier. The extended wall 8 is preferably located approximately six feet (6 ft) or 1.83 meters (1.83 m) or higher above the top of the filter media 2 or its top surface 12, at a gap height H. C The extension wall or extension wall 8 reduces heat loss during windy days and limits the possibility of wastewater from the distributor arm 5 freezing on the distributor arm 5 and / or at the surface of the wastewater in the trickling filter tank 1.

[0023] Another process feature of the preferred trickling filter system 9 is the desired minimum residual alkalinity of 150 to 200 mg / L (150-200 mg / L) of calcium carbonate (CaCO3) to enhance nitrification of the treated effluent in the trickling filter system 9. Nitrifying 1 mg / L (1 mg / L) of ammonia nitrogen into nitrate nitrogen consumes 7.14 mg / L (7.14 mg / L) of alkalinity based on calcium carbonate (CaCO3). Alkalinity balance is preferably calculated to optimize nitrification performance, and the addition of alkalinity to balance the alkalinity can be encouraged.

[0024] Another feature of the preferred trickling filter system 9 is that the structured sheet-like medium 2 of polyvinyl chloride (“PVC”) or polypropylene (“PP”), or other synthetic or polymeric media, can consist of a combination of transverse or transverse flow medium 2a and vertical flow medium 2b, which provides a non-linear flow path through the filter medium 2. As wastewater flows from the top of tank 1 to the bottom and exits the effluent trough 7, prompting the wastewater to take a non-linear flow path or virtually any detour through the medium 2 improves and / or prolongs the contact between wastewater, air, and bacteria.

[0025] Another feature of this preferred trickling filter system 9 is that the design can also be used to improve the oxidation of organic pollutants (i.e., the removal of biochemical oxygen demand and chemical oxygen demand (“BOD / COD”). Therefore, the application of this preferred trickling filter system 9 is not limited to nitrification, but can be extended to BOD coarse filtration, BOD removal, and combinations of BOD removal and nitrification in the trickling filter system 9.

[0026] Another advantage of this preferred trickling filter system 9 is that the energy consumption of the enhanced passive aeration system is significantly lower than that of the active aeration system (e.g., mechanical aeration or diffusion aeration) in the activated sludge process.

[0027] These features and advantages provide an innovative design for the preferred trickling filter system 9 by: incorporating a bottom drainage section with a height H... U A highly enclosed bottom drainage section, storage tank, or bottom drainage section space 6 with a defined gap height H C The extended wall 8-phase combination, combined with a bed depth H M The system comprises a shallow, structured sheet-like medium 2 and an extended container, along with a velocity control dispensing device 5. This design facilitates the creation of a favorable environment within the trickling filter tank 1 for bacterial growth and chemical interactions with the wastewater (heterotrophic organisms for BOD removal and autotrophic organisms for nitrification). Microbiological studies have revealed that the nitrifying colonies in the biofilm of the preferred trickling filter system 9 are denser and better organized compared to the microbial colonies in conventional trickling filter biofilms. The biological treatment capacity and efficiency of this trickling filter system 9 are improved when compared to conventional trickling filters. Tables 1 and 2 attached show the conditions and average DO concentrations collected over a single month in experimental plants and existing technology systems with rock media during the winter in the northeastern United States.

[0028] Referring to Tables 1 and 2, the preferred trickling filter system 9 can be configured to produce a treated effluent with dissolved oxygen (“DO”) typically increased by two to four milligrams per liter (2-4 mg / L) compared to effluent treated by conventional trickling filters. Specifically referring to Table 2, passive aeration in the trickling filter system 9 can be more effective than passive aeration in conventional trickling filters due to the unique design of its improved natural ventilation. Based on Tests 1 and 2 and comparisons with prior art systems in similar conditions with rock media, this results in DO values ​​of more than two to more than three milligrams per liter (>2 mg / L -> 3 mg / L). Specifically, as shown in Table 2, the DO of the effluent from conventional or prior art trickling filters is 8 mg / L. Compared with the DO in the effluent treated by conventional or prior art trickling filters, the DO of the effluent from the prototype preferred trickling filter 9 is 10.26 to 11.75 mg / L (10.26-11.75 mg / L), or greater than 2 to 3 mg / L (2-3 mg / L).

[0029] Table 1

[0030]

[0031] 1 The data represents experimental data collected during a 31-day winter period in the northeastern United States.

[0032] Table 2

[0033] 1 The data represents experimental plant data collected during a 31-day winter period in the northeastern United States. 2 The existing technology system data represents plant data in rocky media collected during a 31-day winter in the northeastern United States.

[0034] A preferred trickling filter system 9 may include an alkalinity supplement, which is configured to be added to the wastewater or effluent in the trickling filter system 9, tank 1, to maintain a residual alkalinity of 150 to 200 mg / L (150-200 mg / L) to promote nitrification activity. The alkalinity supplement may consist of calcium carbonate (CaCO3) or other substances or compounds used to control alkalinity in the trickling filter system 9. The alkalinity supplement is not limited to calcium carbonate (CaCO3) and may also consist of sodium bicarbonate, lime, or other related substances or compounds. Preferably, the dosage of the alkalinity supplement is calculated based on the equivalent of calcium carbonate, but may also be given in other ways based on the preferences or requirements of the designer or operator. The use of an alkalinity supplement is preferred because the nitrification process in the trickling filter system 9 consumes alkalinity. To convert 1 mg / L of ammonium nitrogen to nitrate nitrogen, 7.14 mg / L of alkalinity (calculated as CaCO3) is consumed. The alkalinity in the wastewater can vary throughout the day, and due to the relatively short contact time, the trickling filter system 9 has limited buffering capacity for alkalinity concentration. Therefore, a high concentration of residual alkalinity in the effluent is preferred to maximize the nitrification capacity of the trickling filter system 9.

[0035] The trickling filter system 9 may include residues retained in the storage tank 6. The residues can be configured to generate a biothermal process, providing heat and warming the wastewater flowing into the storage tank 6 from the filter media 2. This heat improves the chemical reactions within the trickling filter system 9, thereby enhancing the efficiency of the system. Composting of the wastewater residues is a biothermal aerobic process that decomposes the organic portion of the residues. The composting process reduces the organic matter in the residues by approximately twenty-five percent (25%). During composting, the heat generated from the decomposition of the organic portion of the residues reduces the moisture content of the residues, stabilizes the residues, and renders them harmless by converting them into usable biosolids to warm incoming wastewater and airflow under cold climatic conditions.

[0036] Bottom drainage section height H U A relatively large space with a temperature difference is formed at the base of tank 1, which promotes air circulation through filter medium 2 because the pressure drop through the shallow filter medium 2 is limited, and airflow can pass through the entire filter medium 2. The bottom drain section is at a height H. U The combination of the media bed depth Hm was designed to increase passive aeration capacity and thus improve the aerobic treatment performance of the trickling filter system 9.

[0037] Those skilled in the art will understand that changes can be made to the preferred embodiments described above without departing from its broad inventive concept. Therefore, it is understood that the invention is not limited to the specific embodiments disclosed, but is intended to cover modifications within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A trickling filter system for treating wastewater and producing treated effluent, the trickling filter comprising: A can, the can having an internal volume; Filter media, which is installed in the tank; A support beam supports the filter medium in the tank between the top surface of the filter medium and the bottom of the tank; A storage pool, the storage pool being defined between the support beam and the bottom of the tank; as well as An extension wall extends above the top surface and is configured to block wind relative to the top surface.

2. The trickling filter system of claim 1, wherein the tank does not include a ventilation opening in the tank near the support beam, and the tank is thus configured to improve airflow circulation and promote the biochemical reaction of wastewater flowing through the filter medium via open grooves in the filter medium.

3. The trickling filter system of claim 1, wherein the height of the bottom drain section is limited between the bottom of the tank and the support beam, the bottom drain section being approximately five to seven feet (5-7 ft) high, and the filter medium defining a media bed depth of approximately four to ten feet (6-10 ft).

4. The trickling filter system of claim 1, wherein the height of the bottom drain section is limited between the bottom of the tank and the support beam, the media bed depth is limited by the filter media, the ratio of the media bed depth to the height of the bottom drain section is 85% to 143%, and it is configured to increase passive aeration capacity and improve aerobic treatment performance.

5. The trickling filter system according to claim 1, further comprising: An alkalinity supplement, which is configured to be introduced into the wastewater in the tank, is configured to maintain a residual alkalinity of 150 to 200 mg / L to promote nitrification activity.

6. The trickling filter system according to claim 1, further comprising: The downstream effluent pipe of the storage tank, the trickling filter system is configured to have a dissolved oxygen of one and a half milligrams per liter or less when the temperature of the filter influent is less than forty-five degrees Fahrenheit.

7. The trickling filter system of claim 1, wherein the extended wall extends at least six feet (6 ft) above the top surface of the filter medium.

8. The trickling filter system of claim 1, wherein the residue is retained in the storage tank and is configured to generate a biothermal process, thereby providing heat and warming the wastewater flowing from the filter media into the storage tank.

9. The trickling filter system according to claim 7, further comprising: The vent in the tank opens into the storage pool.

10. The trickling filter system of claim 1, wherein the filter medium comprises a transverse flow medium and the tank defines a longitudinal axis, the transverse flow medium being configured to cause wastewater to flow at an angle relative to the longitudinal axis.

11. The trickling filter system of claim 1, wherein the filter medium comprises a vertical direct current medium, and the tank defines a longitudinal axis, the vertical direct current medium being configured to cause wastewater to flow generally parallel to the longitudinal axis.

12. The trickling filter system of claim 1, wherein the filter medium comprises a transverse flow medium and a vertical flow medium, the tank defines a longitudinal axis, the transverse flow medium and the vertical flow medium are stacked in the tank, and the filter medium is configured to cause wastewater to flow in a combination that is at an angle to the longitudinal axis and generally parallel to the longitudinal axis.

13. The trickling filter system of claim 1, wherein the filter medium is composed of sheets, the sheets being constructed of a sheet-filled material.

14. The trickling filter system of claim 13, wherein the packing sheet material is composed of a polymer material.

15. The trickling filter system of claim 14, wherein the polymer material is selected from the group consisting of polyvinyl chloride, polypropylene, and polyethylene.

16. The trickling filter system according to claim 1, wherein the filter medium is composed of a non-self-supporting random medium.

17. The trickling filter system according to claim 1, wherein the filter medium consists of a self-supporting media bed.

18. A trickling filter system for treating wastewater and producing treated effluent, the trickling filter comprising: A can, having an internal volume and defining a height; A filter medium is installed in the tank, the filter medium includes a top surface, and the filter medium defines a media bed depth; A support beam supports the filter medium in the tank, and the height of the bottom drain section is limited between the bottom of the tank and the support beam; A storage tank, the storage tank being defined between the support beam and the base of the tank; A distributor configured to introduce wastewater onto the top surface; as well as An extension wall extends above the top surface and defines a gap height, the depth of the medium bed being approximately 85% to 143% of the height of the bottom drain section.

19. The trickling filter system of claim 18, wherein the gap height is approximately six feet and the tank height is approximately twenty feet.

20. The trickling filter system of claim 18, wherein the filter medium comprises a transverse flow medium.

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