Method of wastewater treatment

Abstract

Disclosed herein as a composition for intensifying the treatment of wastewater including biomass fractions of a biofilm biomass disposed on a mobile biofilm carrier, a densified activated sludge, and a conventional suspended growth where the concentrations of the biomass fractions are generated and maintained at selected weight percentages within a wastewater treatment system. Further disclosed are wastewater treatment systems and methods of use thereof.

Description

METHOD OF WASTEWATER TREATMENTCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Application No. 63 / 515,155, filed on July 24, 2023, which is incorporated herein by reference in its entirety.BACKGROUNDField of the Invention

[0002] The present invention is directed to methods of wastewater treatment, and more particularly to control strategies for densified sludge, migrating biofilms, and suspended growth for intensification of biological processes.Brief Description of the Related Art

[0003] Biological methods of treating wastewater can include activated sludge processes using aeration and microorganisms to biologically oxidize contaminants. Activated sludge processes generally include an aeration tank, a liquid / solid separator, and a recycle loop where part of the treated waste is recycled to the aeration tank and the remaining part of the treated waste is discharged for further treatment and / or disposal. Conditions can arise to upset the balance of activated sludge and microorganisms used to provide wastewater treatment. For example, influent of toxic chemicals, biocides, stormwater flooding, and so forth can impact and decrease the effectiveness of wastewater treatment. Changes to the treatment composition can decrease system throughput increasing processing time and costs.

[0004] Therefore, the need remains for systems and methods that maintain a consistent and controllable wastewater composition.SUMMARY OF THE DISCLOSURE

[0005] In an embodiment, a composition for intensifying the treatment of wastewater including biomass fractions of a biofilm biomass disposed on a mobile biofilm carrier, a densified activated sludge, and a conventional suspended growth. The concentrations of biomass fractions are generated and maintained at selected weight percentages within a wastewater treatment system.

[0006] In another embodiment, a wastewater treatment system includes a bioreactor with a composition of biomass fractions, a selector, and an acclimation tank. The composition of biomass fractions includes a biofilm biomass disposed on a mobile biofilm carrier of 0. 1 to15 weight percent, a densified activated sludge of 1 to 55 weight percent, and a conventional suspended growth of 1 to 69 weight percent based on the total weight of the total biomass in the bioreactor.

[0007] In yet another embodiment, a method of treating wastewater with a wastewater treatment system includes charging a bioreactor with untreated wastewater and a composition of biomass fractions, contacting the untreated wastewater with the composition of biomass fractions to provide a treated wastewater, discharging the treated wastewater from the bioreactor into a selector, separating the treated wastewater with the selector into a return activated sludge fraction, an effluent fraction, and a remaining portion of the treated wastewater, discharging the return activated sludge fraction to the bioreactor, discharging the effluent fraction from the system, and discharging the remaining portion of the treated wastewater to an acclimation tank, generating and maintaining the composition of biomass fractions at selected weight percentages in the acclimation tank and discharging the composition of biomass fractions to the bioreactor.

[0008] The above described and other features are exemplified by the following figures and detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Referring now to the figures, which are exemplary embodiments, and wherein the like elements are numbered alike.

[0010] FIG. 1 is a schematic of an embodiment of an exemplary wastewater treatment system;

[0011] FIG. 2 is a schematic of an embodiment of an exemplary wastewater treatment system;

[0012] FIG. 3 is a schematic of an embodiment of an exemplary wastewater treatment system;

[0013] FIG. 4 is a graph illustrating the monthly average sludge volume index (SVI) (milliliters per liter, mL / L) versus month for Example 1 ;

[0014] FIG. 5 is a graph illustrating biochemical oxygen demand (milligrams per milliliter, mg / mL) versus days for Example 2;

[0015] FIG. 6 is a graph illustrating ammonia concentration (mg / mL) versus days for Example 2;

[0016] FIG. 7 is a graph illustrating Total Kjeldahl Nitrogen (TKN) concentration (mg / mL) versus days for Example 2; and

[0017] FIG. 8 is a graph illustrating total nitrogen concentration (mg / mL) versus days for Example 2.DETAILED DESCRIPTION

[0018] Disclosed herein is a composition of biomass fractions (hereinafter composition) for intensifying the treatment of wastewater. The composition includes three biomass fractions: a biofilm biomass disposed on a mobile biofilm carrier, a densified activated sludge, and a conventional suspended growth. The three biomass fractions of the composition are generated and maintained within selected concentration ranges to provide improved water treatment conditions. The combination of materials synergistically provides increased carbon removal, settleability, and constituent removal (such as nitrogen, phosphorus, and carbon).

[0019] Systems and methods to generate and maintain the composition are also disclosed. The systems provide configurations with a recycling functionality to control the component concentrations of the composition during wastewater treatment. In this manner, the concentration of the biomass fractions in the composition can be maintained throughout changes to the waste stream. In some embodiments, the system can incorporate additional features to tailor the system for cost, accessibility, efficiency, and capacity. Further disclosed are methods of producing, maintaining, and using the composition during wastewater treatment. The produced composition can be used to increase wastewater treatment predictability, consistency, and throughput.

[0020] “And / or,” includes any and all combinations of the one or more of the associated listed items.

[0021] “Activated sludge,” as used herein, is defined as an aerated sludge that contains flocculent culture of microorganisms developed under aeration conditions.

[0022] “Biofilm,” as used herein, is defined as at least two microorganisms that are disposed on a surface.

[0023] “Contaminated water,” as used herein, is defined as water with at least one contaminant. Untreated wastewater and contaminated water are used interchangeably herein.

[0024] “Internal mixed liquor return,” as used herein is defined as settled and / or suspended sludge with alkalinity, nitrogen, and carbon that is recirculated and mixed with incoming untreated wastewater.

[0025] “Return activated sludge,” as used herein, is defined as settled activated sludge that is collected in a selector and returned to the bioreactor to mix with incoming untreatedwastewater.

[0026] “Solids retention time,” as used herein, is defined as the time the solid fraction of the wastewater spends in the wastewater treatment system.

[0027] “Waste activated sludge,” as used herein, is defined as sludge removed from the wastewater treatment process. The waste activated sludge contains excess biomass or cell mass and is removed to maintain the biological balance of the wastewater treatment system and / or achieve a specific solids retention time.

[0028] FIG. 1 depicts an exemplary wastewater treatment system 100 (hereinafter system 100) that comprises a bioreactor 106, a selector 108a, and an acclimation tank 115. As shown in FIG. 1, the bioreactor 106 has an inlet stream 123, an aerator 104, a mixer 105, and an outlet to stream 107. Within the bioreactor 106, a mixture of a biofilm biomass 101 disposed on a mobile biofilm carrier 124, a conventional suspended growth 102, and a densified activated sludge 103 is aerated and stirred before discharge downstream to the selector 108a via stream 107. The stream 107 is in fluid communication with a selector 108a. The selector 108a includes an effluent outlet to stream 109, and an outlet to discharge the remaining treated wastewater materials to stream 125 and stream 110. Via stream 125, a portion of the sludge (e.g., return activated sludge) discharged from the selector 108a is charged to the bioreactor 106. The remainder of the treated wastewater (e.g., densified activated sludge) is sent downstream via stream 110. The stream 110 is in fluid communication with a sampling station I l la and a three-way stream diverter 112. Waste activated sludge can be discharged via stream 113. A mixture of treated wastewater including biofilm biomass 101 disposed on a mobile biofilm carrier 124, conventional suspended growth 102, and densified activated sludge 103 is discharged into an acclimation tank 115. The acclimation tank 115 may include an aerator 104 and a mixer 105. The acclimation tank 115 further includes an inlet from stream 121 and an outlet to stream 116. The stream 116 is in fluid communication with a pump 117a or by gravity flow, a three-way stream diverter 126. The treated wastewater can be separated at the three-way stream diverter 126 into stream 119 or stream 120.

[0029] FIG. 2 depicts another embodiment of a wastewater treatment system (hereinafter system 200). System 200 is similar to system 100, except with the addition of a selector 108b and a sampling station 1 1 lb. In the system 200, the additional selector 108b is downstream of the selector 108a and upstream of the acclimation tank 115.

[0030] FIG. 3 depicts yet another embodiment of a wastewater treatment system (hereinafter system 300). System 300 further includes selectors 108b and 108c with a mixingtank 301 downstream of selector 108b and upstream of selector 108c. In system 300, the acclimation tank 115 includes four inlets for wastewater influent (stream 121), separated wastewater downstream of selector 108b (stream 305 and stream 308), and separated wastewater downstream of selector 108c (stream 304).

[0031] In an embodiment, the bioreactor, the selector, and the acclimation tank lie in a recycle loop. In an embodiment, the acclimation tank is optional and may be absent. A recycle loop is one where each component of the loop can be both upstream and downstream of any other component in the loop. For example, in FIG. 1 , the bioreactor 106 lies downstream and upstream of the selector 108a because material discharged from the bioreactor 106 is charged to the selector 108a, while at the same time material discharged from the selector 108a is charged to the bioreactor 106. A portion of the treated material can be continuously removed downstream of the selector 108a from the recycle loop and discharged via stream 109. For example, the biofilm biomass 101 disposed on the mobile biofilm earner 124 and densified activated sludge downstream of the selector can be selectively returned to the process by return to the bioreactor 106. For example, up to 80% of the biofilm material and the densified activated sludge can be returned to the bioreactor, up to 90% of the biofilm material and the densified activated sludge can be returned to the bioreactor, or up to 100% of the biofilm material and the densified activated sludge can be returned to the bioreactor.

[0032] During wastewater treatment, the bioreactor 106 provides a container for the treatment of wastewater (i.e., contaminated water). The bioreactor 106 is charged with influent of contaminated water via stream 123. The bioreactor 106 is also charged with a composition of biomass fractions including of a biofilm biomass 101 disposed on a mobile biofilm carrier 124, a conventional suspended growth 102, and a densified activated sludge 103. In addition to the contaminated water, the bioreactor 106 can be charged with chemical additives, a mobile biofilm carrier 124, a biofilm biomass 101, treated sludge from the contaminated water, and so forth. During water treatment, the composition of biomass fractions in the bioreactor is contacted with wastewater. The composition of biomass fractions provides increased carbon removal, settleability, and constituent removal (such as nitrogen, phosphorus, and carbon) from the wastewater. Each biomass fraction provides treatment of wastewater and at selected weight percentages the biomass fractions within the composition work synergistically to provide an improved treatment process as described below.

[0033] The biofilm biomass 101 is a biofilm or flocculant biomass disposed on amigrating mobile biofilm carrier 124. The biofilm biomass 101 includes microorganisms such as bacteria and protozoa. The biofilm biomass 101 can be a single or heterogeneous species. The species of microorganism for the biofilm biomass 101 are selected based on the composition of the incoming contaminated water, the redox conditions of the bioreactor, and the solids retention time (SRT). The biofilm biomass 101 serves to biodegrade the constituents, such as phosphorus and nitrogen containing chemicals and solids, such as carbonaceous materials, contained in the contaminated water. Proper species selection and concentration of the biofilm biomass 101 improves nutrient removal, reduces suspended fine solids, and reduces total suspended solids. Furthermore, the reduction of total suspended solids and turbidity improves the ultraviolet (UV) transmittance of the treated water to facilitate complementary treatment with a UV disinfection process. The concentration of biofilm biomass 101 in the bioreactor 106 is about 0.1 to about 15 percent by weight (wt%), about 0.5 to about 10 wt%, or about 1 to about 5 wt% based on the total weight of biomass in the bioreactor. The total weight of biomass in the bioreactor can be maintained to provide the selected amount of the biomass fractions. The concentrations of the biomass fractions can be generated and maintained at selected weight percentages within a wastewater treatment system.

[0034] The mobile biofilm carrier 124 is a natural or synthetic substrate providing a substratum for the biofilm biomass 101. In some embodiments, the mobile biofilm carrier 124 includes substratum added to the water treatment process and / or existing substratum particulate within the water treatment process. In some embodiments, the mobile biofilm carrier 124 is not absorbent, does not contain a charge, and / or is inert. The mobile biofilm carrier 124 provides a surface for disposition of the biofilm biomass 101 with a length and a width of about 200 to about 2000 micrometers.

[0035] Conventional suspended growth 102 is biological flocculated biomass of microorganisms that are fully suspended in the contaminated water, independent of a mobile biofilm carrier 124. In other words, unlike the biofilm biomass 101, the microorganisms of the conventional suspended growth 102 are not disposed on a mobile biofilm carrier 124. Controlling the concentration of conventional suspended growth 102 improves biological flocculation and settling of the water treatment process. The concentration of conventional suspended growth 102 in the bioreactor 106 is about 1 to about 69 wt% or about 40 to about 69 wt% based on the total weight of biomass maintained in the bioreactor.

[0036] Densified activated sludge 103 is activated sludge that has been grown into aggregated particles and retained based on improved settling characteristics. Densifiedactivated sludge 103 increases settling, phosphorus removal, and nitrogen removal. The concentration of densified activated sludge 103 is controlled to improve effluent solids concentrations and reduce total suspended solids. As noted above, reduction of total suspended solids facilitates complementary or additional treatment with a UV disinfection process. The concentration of densified activated sludge 103 in the bioreactor 106 is about 1 to about 55 wl% or about 30 to about 55 wl% based the total weight of biomass maintained in the bioreactor.

[0037] The biofilm biomass 101 , the mobile biofilm carrier 124, the conventional suspended growth 102, and the densified activated sludge 103 provide up to 100% of the mixed liquor suspended solids (MLSS) in the bioreactor 106. The concentration of MLSS is about 100 to about 20,000 milligrams per liter measured as total suspended solids in accordance with ASTM D5907.

[0038] The composition of biomass fractions including (a) a biofilm biomass (of about 0.1 to 15 wt%) disposed on a mobile biofilm carrier, (b) a conventional suspended growth (of about 1 to 69 wt%), and (c) a densified activated sludge (of about 1 to 55 wt%) intensifies the wastewater treatment process. The application of the composition of biomass fractions to contaminated water increases the efficiency and throughput of the wastewater treatment. The combination of materials synergistically provides increased nutrient carbon removal, settleability, and constituent removal such as nitrogen and phosphorus. Use of the composition saves time, decreases treatment costs, and increases the treatment capacity of the system.

[0039] Within the system, the bioreactor 106 is in fluid communication with an inlet for an untreated wastewater stream and an outlet for treated wastewater to a selector. In some embodiments, there are a plurality of bioreactors in the system. In some embodiments, the bioreactors can provide complementary microbial growth conditions. For example, the bioreactors can be configured to provide differing redox conditions such as an aerobic bioreactor, an anoxic bioreactor, and / or an anaerobic bioreactor. In embodiments where at least two bioreactors are included in the system, a bioreactor can be in parallel streams and / or in series with the other bioreactors. When the system includes multiple bioreactors, the bioreactors can be separated by a wall, a partition, a baffle, or a combination thereof. Material flow through the plurality of bioreactors can be free flowing or mechanically pumped upstream or downstream. In some embodiments, the system can include 1 to 10 bioreactors.

[0040] As shown in FIG. 1, the bioreactor 106 can be an aerator. Aerobic bioreactorscan be aerated with added oxygen via an aerator 104 with oxygen containing gas and / or via mechanical aeration with oxygen in the atmosphere using a mixer 105. In some embodiments, aeration is performed with mechanical mixing, diffusers, and combinations thereof.

[0041] The selector is downstream of the bioreactor 106 in fluid communication via stream 107. The selector can be upstream of an acclimation tank 115. The selector can be a liquid / solid separating unit and / or a solid / solid separating unit separating the treated wastewater discharged from the bioreactor 106 by physical, gravimetric, chemical, and / or metabolic biological processes. The selector provides control over the concentration of the biofilm biomass 101, the mobile biofilm earner 124, the conventional suspended growth 102, and the densified activated sludge 103. For example, the selector can facilitate the separation of the treated wastewater stream based on a particle size, density, compressibility, chemical, and / or biological composition. Suitable selector types include, filters (e.g., a static side hill screen, a rotary drum screen, or the like), gravimetric clarifiers, lamella clarifiers, up flow clarifiers, dissolved air flotation systems, hydrocyclones, and the like. The selectors can provide gravimetric sludge selection to enhance the efficiency of wastewater treatment. The gravimetric sludge selection process can lead to improvements in sludge volume index, nitrogen concentration, biochemical oxygen demand, and so forth. The selector(s) can work to separate alone, or in combination, various materials such as return activated sludge, migration biofilm carrier return, densified sludge return, or the like.

[0042] In some embodiments there are a plurality of selectors in the system, e.g., two, three, four, or five selectors. The selectors can be in series and / or parallel streams downstream of the bioreactor 106, upstream of the acclimation tank 115, or downstream of the acclimation tank 115. In some embodiments, the selectors can be upstream or downstream of a mixing tank. As shown in FIG. 2, the selector 108b is downstream of selector 108a and upstream of the acclimation tank 115. The selectors can have an outlet to discharge waste activated sludge, e.g., via streams 109, 204, and 302. For example, the selector 108b can have an inlet for treated wastewater (e.g., densified activated sludge) via stream 110, an outlet for waste activated sludge via stream 204, and an outlet for separated wastewater (e.g., densified activated sludge) via stream 202. The selector 108b can be downstream of a sampling station I l la and upstream of another sampling station 11 lb. As shown in FIG. 3, the selector 108b can include an outlet to the acclimation tank via stream 305 and an outlet to a three-way stream diverter 307 via stream 306. In system 300, the selector 108c is downstream of a mixing tank 301 and upstream of the acclimation tank 115.

[0043] The system can include a sampling station 111. The sampling station 111 can be downstream of the bioreactor 106, downstream of the selector 108a, and / or downstream of the acclimation tank 115. The sampling station 11 1 can be within the bioreactor 106, the selector 108a, and / or the acclimation tank 115. In some embodiments, there are a plurality of sampling stations throughout the system. As shown in FIG. 2 and FIG. 3, the system can include sampling stations I l la and 11 lb. In some embodiments, the system has 1 to 6 sampling stations.

[0044] The sampling station 1 1 la provides sampling output data to facilitate treatment monitoring. The sampling station 11 la can measure bacterial metabolic activity, influent and effluent constituent concentrations, solids concentrations, settleability, particle counts, particle size, and the like. Based on sampling data, a system operator can increase or decrease flow from the bioreactor 106, the influent stream, and / or the acclimation tank 115. In addition, the system operator can adjust chemical levels, raise the concentration of the mobile biofilm carrier 124, and so forth.

[0045] The optional acclimation tank 115 can be downstream of a selector and upstream of the bioreactor 106. The acclimation tank 115 has an inlet or multiple inlets for treated wastewater (via streams 114, 202, 304, 305, and / or 308) and an inlet for untreated influent via stream 121. Influent flow from stream 123 into the acclimation tank via stream 121 can be controlled with a two-way stream divertor 122. In some embodiments, there are a plurality of acclimation tanks in the system. As described for the bioreactor 106, the acclimation tank 115 can be configured to provide complementary microbial growth conditions via aerobic, anoxic, and / or anaerobic conditions. In embodiments where at least two acclimation tanks 115 are included in the system 100, an acclimation tank can be in parallel streams and / or in series with the other acclimation tanks. In some embodiments the acclimation tank 115 can be configured to provide switchable redox conditions. As shown in the figures, the acclimation tank 106 can provide aerobic conditions via an aerator 104 and the use of a mixer 105.

[0046] The acclimation tank 115 can include inline sensors and sample ports to monitor the biological activity, biological flocculant concentrations, and the mixed liquor suspended solids concentrations. Based on treatment conditions, the solids can be recycled to the bioreactor 106 via stream 120 or discharged (“wasted”) from the treatment system as waste activated sludge via stream 119. As shown in FIG. 1, a pump 117a can be placed downstream of the acclimation tank 115 and upstream of a three-way stream diverter 126.The three-way stream diverter serves to control the flow of discharged treated material fromthe acclimation tank 115 to stream 120 or to stream 119.

[0047] Pumps can be downstream of the bioreactor 106, downstream of the selector, downstream of the acclimation tank 115, and / or downstream of a mixing tank 301. Pumps can facilitate the movement of material flow through the wastewater treatment system. In some embodiments, there are multiple pumps throughout the system. As shown in FIG. 3, a pump 117b is downstream of the mixing tank 301 and a pump 117a is downstream of the acclimation tank 115. In some embodiments, the system has 1 to 6 pumps.

[0048] In some embodiments a mixing tank 301 can be included in the system. The mixing tank 301 provides a container for mixing treated wastewater downstream of a selector and upstream of another selector. As described for the bioreactor 106 and the acclimation tank 115, the mixing tank 301 can be configured to provide aerobic, anoxic, and / or anaerobic microbial growth conditions. In some embodiments, additives and chemicals can be added to the treated wastewater within the mixing tank 301 to facilitate processing of the wastewater. In other embodiments, the mixing tank 301 provides only a mixing stage for the treated wastewater before discharge to an additional selector.[0049| The streams 107, 109, 110, 114, 113, 116, 119, 120, 121, 123, 125, 202, 204, 302, 303, 304, 305, 306, 309, and 310 that transport untreated wastewater, treated wastewater, and waste activated sludge comprise conduits for material flow. As shown in the figures, the flow of material is denoted by arrows on the streams.

[0050] Additional features of sensors and sampling stations can be present throughout the system. The sampling can provide feedback for systems to control aeration, solids retention time, or the like.

[0051] A method of treating contaminated water includes contacting untreated wastewater (i.e., contaminated water) with a composition of biomass fractions. The untreated wastewater and a composition of biomass fractions are charged into a bioreactor. The wastewater is contacted in the bioreactor with the composition of biomass fractions under aerobic, anoxic, and / or anerobic conditions. The treated wastewater is discharged to a selector. The selector separates the treated wastewater into waste activated sludge and a remaining portion of the treated wastewater into separated treated wastewater. The waste activated sludge is discharged from the system. A portion of the sludge in the remaining separated treated wastewater can be charged into the bioreactor as returned sludge. The remainder of the separated treated wastewater (without the returned sludge) can be charged into an acclimation tank. In the acclimation tank, the concentration of biomass fractions in the remaining separated treated wastewater are adjusted to the selected weight percentages of theinitial composition of biomass fractions in the bioreactor. Discharging a portion of the composition of biomass fractions from the acclimation tank to the bioreactor completes the recycle loop of the wastewater treatment system.

[0052] In some method embodiments, a portion of untreated wastewater (e.g., contaminated water) is charged to the acclimation tank. In other embodiments, a sampling station monitors the discharge of separated treated wastewater from the selector to accommodate process adjustments. Process adjustments can include the removal of a portion of waste activated sludge, increases in oxygenation levels, addition of a mobile biofilm carrier, and so forth.EXAMPLES

[0053] Measurements of various water quality variables were collected in accordance with the Standard Methods for the Examination of Water and Wastewater from different wastewater treatment systems. Details for the water quality variables sampled are listed in Table 1. The wastewater treatment systems were fitted with a Gravimetric Sludge Selector and a Biofilm Carrier System where noted.Table 1. Water Quality Variable AbbreviationsExample 1. SVI with Gravimetric Sludge Selection

[0054] The sludge volume index (SVI) for an Anaerobic-Anoxic-Aerobic (A2O) Process Wastewater Treatment System with a flow of 10 million gallons per day was assessed with and without a gravimetric sludge selection system (i.e., a hydrocyclone selector and so forth). The gravimetric sludge selection system was added to a conventional A2O Process System within the waste activated sludge line. The Wastewater Treatment System did not include a Biofilm Carrier System. As shown in FIG. 4, the monthly average SVI for the system without the gravimetric sludge selection was substantially greater than the system with the gravimetric sludge selection. The implementation of gravimetric sludge selection provides substantial improvement in SVI in comparison to conventional systems.Example 2. Performance of a Wastewater System with a Biofilm Carrier System

[0055] Multiple wastewater quality variables were assessed for a Modified Ludzack- Ettinger (MLE) Process Wastewater Treatment System with clarifiers for sludge selection with a flow of 1.7 million gallons per day. Where noted, the Wastewater Treatment System was fitted with a Biofilm Carrier System with Particle Size Selectors. Daily measurements over a 6-month period are shown in FIGS. 5 to 8 for influent and effluent samples. As shown in FIGS. 5 to 8, the system effectively decreased the Biological Oxygen Demand (BOD), Ammonia Concentration (NH3), Total Kjeldahl Nitrogen (TKN), and Total Nitrogen (TN) from the influent to the effluent.

[0056] On Day 115, a Biofilm Carrier System was installed in the Wastewater Treatment System. The average values of the ammonia, TKN, and TN of the effluent decreased after installation of the Biofilm Carrier System and the variation in the data also decreased (i.e., decreased standard deviation), see Table 2. Accordingly, the disclosed wastewater treatment system provides improved process consistency and efficiency.Table 2. Average Nitrogen Concentrations

[0057] While the disclosure has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without departing from essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A composition for intensifying the treatment of wastewater comprising biomass fractions of: a biofilm biomass disposed on a mobile biofilm carrier; a densified activated sludge; a conventional suspended growth; wherein concentrations of the biomass fractions are generated and maintained at selected weight percentages within a wastewater treatment system.

2. The composition of claim 1, wherein the biomass fractions make up 100% of the mixed liquor suspended solids in the wastewater treatment system.

3. The composition of claim 1, wherein in the wastewater treatment system, the biofilm biomass comprises 0.1 to 15 weight percent of the total weight of biomass in a bioreactor in the wastewater treatment system; the densified activated sludge comprises 1 to 55 weight percent of the total weight of biomass in the bioreactor; and the conventional suspended growth comprises 1 to 69 weight percent of the total weight of biomass in the bioreactor.

4. The composition of claim 1, wherein the application of the composition to wastewater increases the nutrient removal, settleability, and / or constituent removal.

5. A wastewater treatment system comprising a bioreactor with a composition of biomass fractions; a selector; and an acclimation tank; wherein the composition of biomass fractions comprises a biofilm biomass disposed on a mobile biofilm carrier of 0.1 to 15 weight percent based on the total weight of biomass in the bioreactor ; a densified activated sludge of 1 to 55 weight percent of the total weight of biomass in the bioreactor and a conventional suspended growth of 1 to 69 weight percent based on the total weight of biomass in the bioreactor.

6. The system of claim 5, wherein the bioreactor, the selector and the acclimation tank are arranged in a recycle loop.

7. The system of claim 5, wherein the system further comprises a sampling station.

8. The system of claim 5, wherein the system further comprises a mixing tank.

9. The system of claim 5, wherein the system further comprises a plurality of selectors.

10. The system of claim 6, wherein the selector facilitates the separation of treated wastewater by physical, gravimetric, chemical, and / or metabolic biological processes.

11. The system of claim 6, wherein the selector is a filter, a gravimetric clarifier, a lamella clarifier, an up-flow clarifier, a dissolved air flotation system, a hydrocyclone, or a combination thereof.

12. A method of treating wastewater with a wastewater treatment system comprising: charging a bioreactor with untreated wastewater and a composition of biomass fractions, contacting the untreated wastewater with the composition of biomass fractions to provide a treated wastewater; discharging the treated wastewater from the bioreactor into a selector; separating the treated wastewater with the selector into a return activated sludge fraction, an effluent fraction, and a remaining portion of the treated wastewater; discharging the return activated sludge fraction to the bioreactor, discharging the effluent fraction from the system, and discharging the remaining portion of the treated wastewater to an acclimation tank; generating and maintaining the composition of biomass fractions at selected weight percentages in the acclimation tank and discharging the composition of biomass fractions to the bioreactor.

13. The method of claim 12, wherein the method further comprises sampling via a sampling station.

14. The method of claim 12, wherein the sampling station measures bacterial metabolic activity, influent constituent concentrations, effluent constituent concentrations, solids concentrations, settleability, particle counts, particle size, or a combination thereof.

15. The method of claim 13, wherein the method further comprises sampling via a plurality of sampling stations.

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