Electrified anaerobic baffled reactor

Abstract

Systems and methods for onsite wastewater treatment systems comprising multi-chamber anaerobic baffle reactors and bioelectrochemical systems are disclosed herein.

Description

KPPB Ref: S94-09918.PCTELECTRIFIED ANAEROBIC BAFFLED REACTORCROSS-REFERENCES TO RELATED APPLICATIONS

[0001] The current application claims priority to Provisional Application No.63 / 765,312, filed February 28, 2025, the disclosure of which is incorporated herein by reference.FIELD OF THE INVENTION

[0002] This disclosure generally refers to systems and methods for anerobic treatments technologies for removing organic constituents, nutrients, and solids from wastewater. This disclosure generally refers to systems and methods of wastewater treatment, anaerobic baffled reactors (ABRs), and bioelectrochemical systems (BESs). A Bioelectrochemical System (BES) uses living microbial communities (for example, Bacteria, Archaea) and tailors a bioreactor environment to promote processes such as the generation of current, microbial metabolisms, the production of electrochemically active proteins and / or redox reactions.BACKGROUND

[0003] An anaerobic baffled reactor (ABR) is a standard anaerobic treatment technology for removing organic constituents and solids from wastewater. The typical configuration of the ABR has 3-8 chambers with widely-spaced and closely-spaced baffle walls so that wastewater flows into the first chamber, depositing solids in between widely-spaced walls, and then flows over the first wall and under the second closely-spaced baffle wall reaching the next chamber.SUMMARY OF THE INVENTION

[0004] Systems and methods in accordance with some embodiments of the invention are directed to bioelectrochemical systems comprising anaerobic baffled reactors.

[0005] In some embodiments, the techniques described herein relate to a wastewater treatment system including one or more anaerobic baffled reactors wherein the one orKPPB Ref: S94-09918.PCTmore anaerobic baffled reactors includes a bioelectrochemical system with one or more anaerobic baffled reactors.

[0006] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein the one or more anaerobic baffled reactors further includes one or more chambers.

[0007] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein intermittent aeration is applied to the one or more chambers.

[0008] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein the one or more chambers include zero valent iron.

[0009] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein one or more chambers include an aeration supplement.

[0010] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein the aeration supplement is one or more rocks.

[0011] In some embodiments, the techniques described herein relate to a wastewater treatment system, further including a multi-chamber anaerobic baffle reactor including four or more chambers; wherein the four or more chambers are in series.

[0012] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein the one or more anerobic baffle reactor includes: an anode; a cathode, wherein the cathode is surrounded by a conductive material; and two or more baffle walls, wherein the anode and the cathode are placed between the two or more baffle walls; wherein the anode and the cathode are in electrical connection.

[0013] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein the conductive material is a conductive mesh.

[0014] In some embodiments, the techniques described herein relate to a wastewater treatment system, wherein the anode and the cathode are connected by an external circuit; wherein an external potential is applied to the external circuit.

[0015] In some embodiments, the techniques described herein relate to a method of wastewater treatment including: providing wastewater to a wastewater treatment system including one or more anaerobic baffled reactors; wherein the one or more anaerobic baffled reactors includes a bioelectrochemical system with one or more anaerobic baffledKPPB Ref: S94-09918.PCTreactors; wherein the one or more anerobic baffle reactor includes: an anode; a cathode, wherein the cathode is surrounded by a conductive material; and two or more baffle walls, wherein the anode and the cathode are placed between the two or more baffle walls; wherein the anode and the cathode are in electrical connection; and applying at least one of a voltage or a current to the anode and the cathode.

[0016] In some embodiments, the techniques described herein relate to a method, wherein the conductive material is a conductive mesh.

[0017] In some embodiments, the techniques described herein relate to a method, wherein the conductive mesh is at least one of stainless steel or carbon felt.

[0018] In some embodiments, the techniques described herein relate to a method, wherein the anode and the cathode are connected by an external circuit.

[0019] In some embodiments, the techniques described herein relate to a method, wherein the step applying at least one of the voltage or current initiates an electrochemical reaction within the biochemical system.

[0020] In some embodiments, the techniques described herein relate to a method, wherein the one or more anaerobic baffled reactors further includes one or more chambers.

[0021] In some embodiments, the techniques described herein relate to a method, wherein one or more chambers include an aeration supplement.

[0022] In some embodiments, the techniques described herein relate to a method, wherein the aeration supplement is one or more rocks.

[0023] In some embodiments, the techniques described herein relate to a method, further including a multi-chamber anaerobic baffle reactor including four or more chambers.

[0024] In some embodiments, the techniques described herein relate to a method, wherein the four or more chambers are in series.

[0025] Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the disclosure. A further understanding of the nature and advantages of the present disclosure may be realizedKPPB Ref: S94-09918.PCTby reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The description will be more fully understood with reference to the following figures, which are presented as embodiments of the invention and should not be construed as a complete recitation of the scope of the invention, wherein:

[0027] Figures 1A and 1B schematically illustrates a bioelectrochemical system comprising anaerobic baffled reactors.

[0028] Figure 1C provides a table of operation of a wastewater treatment system in accordance with several embodiments.

[0029] Figure 2 graphically illustrates the mean dissolved oxygen (DO) measurements of the Influent, ABR1C1, ABR1C2, ABR1C3, ABR2C1, ABR2C2, and ABR2C3 in Example 1 (n=5), Example 2 (n=12), Example 3 (n=7), and Example 4 (n=8). Error bars represent one standard deviation.

[0030] Figure 3 graphically illustrates the mean total dissolved solids (TDS) measurements of the Influent, ABR1C1, ABR1C2, ABR1C3, ABR2C1, ABR2C2, and ABR2C3 in Example 1 (n=5), Example 2 (n=12), Example 3 (n=7), and Example 4 (n=8). Error bars represent one standard deviation.

[0031] Figures 4A to 4D graphically illustrate COD concentrations and percent COD removal in Examples 1-4 from influent to A2C3. Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0032] Figures 5A and 5B graphically illustrate DOC concentrations and percent DOC removal in Examples 3 and 4 from influent to A2C3. Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0033] Figures 6A and 6B graphically illustrate the concentration and removal of total COD and soluble COD (sCOD) in the feed, A1C3, and A2C3 chambers during Example 5 and Example 6.

[0034] Figures 7A and 7B graphically illustrates DOC concentrations and percent DOC removal (from feed to A2C3) in influent, effluent, and each chamber of ABR1 and ABR2KPPB Ref: S94-09918.PCTfor Example 5 (Figure 7A) and Example 6 (Figure 7B). Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0035] Figures 8A and 8B graphically illustrate the concentrations of ammonium, nitrite-N, and nitrate-N in influent, A1C3, and A2C3 during Example 2 (with aeration only, A) and Example 3 (with BES only. B). Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0036] Figures 9A and 9B graphically illustrates the TDN concentration in each chamber and the percent removal for Example 3 (Figure 9A) and Example 4 (Figure 9B), calculated as the percent difference between chamber A1C1 concentrations and A2C3 concentrations. Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0037] Figures 10A and 10B graphically illustrates the ammonia-N concentration in each chamber and the percent removal for Example 3 (Figure 10A) and Example 4 (Figure 10B), calculated as the percent difference between chamber A1C1 concentrations and A2C3 concentrations. Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0038] Figures 11A and 11 B graphically illustrates the TDN concentration in each chamber and the percent removal for Example 5 (Figure 11 A) and Example 6 (Figure 11 B), calculated as the percent difference between chamber A1C1 concentrations and A2C3 concentrations. Mean shown as ‘x’, boxes denote quartiles, and error bars denote standard deviations.

[0039] Figure 12 graphically illustrates the ammonium concentration in each chamber and the percent removal for Example 5 and Example 6, calculated as the percent difference between chamber A1C1 concentrations and A2C3 concentrations. Mean shown as x', boxes denote quartiles, and error bars denote standard deviations.

[0040] Figures 13A and 13B graphically illustrates the Excitation-Emission Matrices (EEMs) collected during Example 5 (Figure 13A) and 6 (Figure 13B), which both show the presence of the methanogen F420 peak at excitation of ~420 nm and emission of -470 nm.KPPB Ref: S94-09918.PCTDETAILED DESCRIPTION OF THE INVENTION

[0041] It will be understood that the components of the embodiments, as generally described herein and illustrated in the appended figures, may be arranged and designed in a variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the present disclosure but is merely representative of various embodiments. While various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0042] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

[0043] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussions of the features and advantages and similar language throughout this specification may, but do not necessarily, refer to the same embodiment.

[0044] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.

[0045] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment. Thus, the phrases “in one embodiment,” “in an embodiment,” andKPPB Ref: S94-09918.PCTsimilar language throughout this specification may but do not necessarily, all refer to the same embodiment.

[0046] Anaerobic baffled reactors (ABR) are used extensively in other countries (India, South Africa, Indonesia, etc.) as an alternative to a septic tank, but are not commonly used in the USA. There are no existing anaerobic onsite wastewater treatment systems (to the knowledge of the inventors) that utilize the baffled reactor configuration to enable the function of a bioelectrochemical system. In some embodiments, the bioelectrochemical system may have various configurations. In various embodiments a bioelectrochemical system may comprise one or more multi-chamber ABRs in series. In some embodiments a bioelectrochemical system may comprise a multi-chamber ABR wherein the multi-chamber ABR comprises four or more chambers. Many embodiments may be utilized to treat organic waste. A replacement for excreta-containing waste treatment systems, like septic tanks, that reduces the discharge of organic compounds, solid materials, and nutrients that would normally be discharged into leach fields or out of open pipes. This replacement system should fit within 1.5 times the footprint of a traditional septic tank and should reduce the effluent pollutant concentrations by more than 30% over traditional septic tanks.

[0047] In some embodiments, the wastewater system can comprise one or more multichamber ABRs. The wastewater system can be configured with two ABRs in series. The first ABR can be configured to primarily remove solids and / or organic matter. The second ABR can be configured to primarily remove nutrients. In various embodiments, the second ABR can also be configured for electrochemically enhanced redox transformations. The redox transformations can be configured to remove nutrients from the wastewater. In certain embodiments, the wastewater system can comprise between about four and eight chambers. The multi-chambers can be arranged in alternating downflow and upflow hydraulic zones. In many embodiments, the multi-chambers are configured such that the wastewater flows beneath the baffle walls and upward through sludge blankets. This configuration can promote staged anaerobic digestion. In certain embodiments, the wastewater system can operate as a batch system. The wastewater system can operate as a continuous flow system, in some embodiments, the wastewater system can operateKPPB Ref: S94-09918.PCTunder baseline hydraulic loading. The wastewater system can operate under an elevated hydraulic loading conditions simulating household overloading. In some embodiments hydraulic retention time and flow rates in hydraulic loading can be adjusted to modulate treatment efficiency.

[0048] A proton exchange membrane is typical in bioelectrochemical systems. In many embodiments, the ABR has an anode mesh in one chamber, a cathode mesh in another chamber, and a chamber in between the two, where the proton transfer occurs. One or more of the initial ABR chambers in the bioelectrochemical systems of many embodiments may incorporate and / or operate according to conventional techniques to treat organic constitutes and solids. One or more of the subsequent bioelectrical systems of many embodiments may comprise a cathode-with-conductive material and anode-with-conductive material. In an embodiment with one or more multi-chamber ABRs in series, the first multi-chamber ABR may operate according to conventional methods and the second multi-chamber ABR may comprise a cathode-with-conductive-material and anode-with-conductive material. In an embodiment with a multi-chamber ABR with four or more chambers the first two chambers may operate according to conventional techniques and the third and fourth chambers may comprise a cathode-with-conductive-material and anode-with-conductive material. Figures 1A and 1B provide wastewater treatment systems in accordance with various embodiments.

[0049] Figure 1A provides a wastewater treatment system 100 comprising an upstream multi-chamber ABR 101 and a downstream multi-chamber ABR 102. The upstream multi-chamber ABR 101 can be configured for organic matter and solids removal. The downstream multi-chamber ABR 102 can be configured for nutrient removal. The downstream multi-chamber ABR 102 can further comprise an anode chamber 103 and a cathode chamber 104. Figure 1B provides a multi-chamber wastewater treatment system 110 comprising an anode chamber 103, a cathode chamber 104, and one or more intermediate chambers 105. In Figure 1A, both the upstream multichamber ABR 101 and the downstream multi-chamber ABR 102 comprise one or more intermediate chambers 105. The anode 106 and the cathode 107 are disposed in separate chambers but are electrically connected. At least one of the anode chamber 103KPPB Ref: S94-09918.PCTand the cathode chamber 104 can comprise a biological and / or microbial community. The biological and / or microbial community can comprise living Bacterial and / or Archaea. In certain embodiments, organic compounds can be oxidized in the anode chamber 103 to produce biomasses and CO2. In various embodiments, ammonium can be transformed through electrochemical oxidation, biological nitrification, denitrification, and / or anammox pathways. In the cathode chamber 104, methane (CH4) and / or hydrogen gas (H2) can be produced. In the cathode chamber 104, nitrate, nitrite, CO2, or any combination thereof can be reduced.

[0050] In many embodiments, the wastewater can flow sequentially through alternating downflow and upflow zones. The wastewater can flow into the upstream chamber and exit in effluent exits in the downstream chamber. Optionally, recirculated streams can be introduced into upstream chambers. In some embodiments, redox-active media cab be disposed in one or more chambers.

[0051] Figure 1C provides a table of operation of a wastewater treatment system in accordance with several embodiments.

[0052] In many embodiments the electrode-with-conductive material may be a stainless steel electrode surrounded by a stainless steel scrubby made entirely from thin, intertwined stainless steel wire mesh. In some embodiments the electrode-with-conductive material may be a carbon felt. In various embodiments, the ABR can fomprise a conductive media disposed within one or more chambers. The conducive media can optionally be stainless steel mesh, carbon fiber, graphene-based materials, or other electrically conductive structures. In numerous embodiments, the conductive media is configured to enhance electron transfer and / or biofilm development. One or both electrodes may be is inserted into the mesh, and the assembly is placed between two of the more closely-spaced baffle walls. In another embodiment, the electrode-mesh assemblies may be placed in between two of the more widely-spaced baffle walls. In various embodiments the electrodes can be at least one of an anode, a cathode, a bioanode, a biocathode, or any combination thereof. In some embodiments, a bioanode is positioned within a chamber of the ABR. The bioanode can optionally be placed between closely spaced baffle walls. The bioanode can optionally be disposed within aKPPB Ref: S94-09918.PCTnarrow baffle region or within a widened chamber region. In certain embodiments, the bioanode can be inoculated with a mixed microbial community. The mixed microbial community can comprise naturally occurring wastewater microorganisms. The wastewater microorganism can optionally include exoelectrogenic bacteria, facultative anaerobes, fermentative bacteria, and / or ammonia-oxidizing microorganisms. In some embodiments, the biocathode is positioned downstream of the bioanode. The bioanode can be inoculated with naturally occurring wastewater microorganisms and / or anaerobic microorganisms. In various embodiments, the anaerobic microorganisms can optionally include anammox bacteria, methanogenic Archaea, mixed anaerobic cultures, electrotrophic microorganisms, or engineered microbial communities.

[0053] The anode and cathode can be configured so that the anode is upstream or downstream of the cathode. In many embodiments, the cathode may be abiotic and comprise conductive materials selected from at least one of stainless steel mesh, stainless steel scrub structures, carbon felt, carbon fiber, graphene mesh, graphene fiber, or any combination thereof. The anode and cathode may be connected by an external circuit, which allows electrons to flow from anode to cathode. The anode and the cathode can be operably linked to a potentiostat, power supply, photovoltaic system, battery system, and / or an electrical grid connection. Any instrument designed to control the working electrode’s potential in the electrode electrochemical cell can be used, such as a power supply or a photovoltaics device. An external voltage or current may be applied to drive the electrochemical reactions within the bioelectrochemical systems. In many embodiments, an applied electrical potential can be maintained between the anode and the cathode. The applied electrical potential can optionally comprise at least one of constant voltage operation, constant current operation, pulsed voltage operation, pulsed current operation, periodic polarity reversal, and / o any combinations thereof. In various embodiments, the applied voltage can be greater than or equal to 0.5V. In certain embodiments, the applied voltage can be less than or equal to 1.5V. The applied voltage can change when scaling up in size of the electrode. In many embodiments, the applied current can be maintained at a substantially constant amperage. In certain embodiments, polarity reversal can be applied periodically to regulate biofilm thickness, reducing fouling,KPPB Ref: S94-09918.PCTstimulate specific microbial communities, and / or enhance nitrogen transformation pathways.

[0054] The electrochemical reactions result in further removal of organic constituent and promote total nitrogen reduction. The production of nitrite during electrochemical oxidation of ammonium supports the growth of anammox bacteria that convert NH4 and NO2 to N2 gas, hence the removal of ammonium from the wastewater. Production of nitrate during electrochemical oxidation also may occur. Nitrate may then be electrochemically reduced at the cathode to produce nitrite, which also may support the growth of anammox bacteria. Nitrate also may be converted to N2 gas by denitrifying bacteria in the presence of a carbon source. This mixed consortium of anammox and denitrifiers also may lead to the removal of ammonium from the system. In various embodiments, the ABR can comprise redox-active additives. The redox-active additives can be configured to enhance electron transfer, promote denitrification, stimulate methanogenesis, and / or enhance ammonium transformation. The redox-active additives can optionally be selected from at least one of zero-valent iron (Fe°), iron filings, metals, nanoparticles, metal oxides, or any combinations thereof.

[0055] The bioelectrochemical system of many embodiments may be supplemented with aeration in one or more of the chambers. Wastewater systems, in accordance with certain embodiments, can control aeration in one or more chambers by optionally applying aeration intermittently, continuously, or during pumping cycles. In many embodiments, aeration promotes partial nititation, nitrification-denitrification pathways, and / or redox stratification. The wastewater system can further comprise effluent recirculation pathways. The recirculation pathways can optionally be returning effluent or internal process streams to upstream champers. In many embodiments the recirculation pathways can be influent lines to enhance denitrification, reduce sludge accumulation, and / or stabilize hydraulic performance. In some embodiments, the ABR comprises sorptive media configured to promote biofilm growth and / or nutrient adsorption. Rocks or other media may be added to one or more of the chambers to promote the growth of biofilms and other attached organisms or to provide slow-release metals or other chemicalKPPB Ref: S94-09918.PCTconstituents. In many embodiments, the sorptive media is volcanic rock, inorganic rock media, or other porous materials.

[0056] Various embodiments are directed to a method of oxidizing raw and / or pretreated wastewater through a biological and / or microbial community in an anode chamber for the use of nutrient removal, redox transformation, methane production, and / or enhanced nitrogen removal in a biocathode. In some embodiments oxidizing raw and / or pretreated wastewater methods promote ammonium oxidation, nitrite / nitrate production, denitrification, and / or anammox processes in downstream chambers. In various embodiments, methods for oxidizing raw and / or pretreated wastewater remove nitrogen species in a downstream chamber using an abiotic cathode. For example, methods described herein, can enhance total dissolved nitrogen removal exceeding approximately 50% as compared to a non-electrified anaerobic baffled reactor. The methods described herein can remove chemical oxygen demand exceeding about 75%, about 90% using an electrified ABR configuration.EXAMPLESExample 1: Baseline ABR (no aeration)

[0057] This example demonstrates that products of manufacture as provided herein are effective as anaerobic baffled reactors (ABRs) for organic matter removal under strictly anaerobic conditions, in the absence of aeration and in the absence of applied electrical potential.

[0058] An exemplary reactor as provided herein comprised two laboratory-scale acrylic anaerobic baffled reactors (ABR1 and ABR2) connected in series. Each reactor was divided into three chambers (A1C1-A1C3 and A2C1-A2C3) using vertical baffle walls configured to create alternating downflow and upflow hydraulic zones. Wastewater entering each chamber was directed beneath a baffle wall and upward through a sludge blanket region to promote anaerobic digestion and solids retention.

[0059] The combined working volume of the system was approximately 15.5 L. The reactors were loosely covered with opaque lids and maintained under anaerobicKPPB Ref: S94-09918.PCTconditions without active aeration. Reactor temperatures ranged between approximately 20°C and 40°C, representative of typical septic wastewater temperatures.

[0060] In this exemplary configuration, no bioelectrochemical system (BES) was installed. No anode, cathode, or external circuit was present. No electrical potential was applied across any chamber. The system therefore operated as a conventional anaerobic baffled reactor baseline control.

[0061] Inorganic rock media were placed in downstream chambers (A1 C3 and A2C3) to promote biofilm formation and enhance solids retention. No zero-valent iron, nanoparticles, conductive mesh, or redox-active additives were introduced during this example.

[0062] The influent wastewater comprised a synthetic high-strength organic substrate formulated to simulate domestic wastewater. The influent chemical oxygen demand (COD) ranged from approximately 200 mg / L to 700 mg / L. Total dissolved nitrogen (TDN) ranged from approximately 30 mg N / L to 60 mg N / L.

[0063] Organic carbon was supplied via a protein- and lipid-rich substrate. Ammonia nitrogen was supplemented to achieve a controlled carbon-to-nitrogen ratio representative of household wastewater.

[0064] During Example 1, feeding was conducted under a baseline hydraulic regime consisting of pumping for 1 hour at 0.83 L / h, followed by 3 hours of rest, and then a repeat of the pattern. This flow regime simulated wastewater generation equivalent to approximately a four-person household producing about 400 gallons per day when scaled to full size. The Example 1 baseline ABR operation was conducted for approximately 78 days under steady-state anaerobic conditions.

[0065] Water quality parameters were monitored weekly at the influent and at each chamber (A1C1-A2C3). Samples were collected approximately one hour after completion of the feeding cycle to ensure stabilized hydraulic conditions. The following parameters were measured: pH, Dissolved oxygen (DO), Electrical conductivity (EC), Total dissolved solids (TDS), Chemical oxygen demand (COD), Dissolved organic carbon (DOC), Total dissolved nitrogen (TDN), Ammonium (NH4+-N), Nitrite (NO2"-N), and Nitrate (NO3’-N).KPPB Ref: S94-09918.PCT

[0066] During Example 1 , DO was low for each of the compartments in the two ABRs (Figure 2). TDS concentrations remained relatively unchanged throughout the system (Figure 3). Organic matter removal occurred through conventional anaerobic digestion mechanisms. COD removal from influent to the final chamber (A2C3) averaged approximately 75-76% (Figure 4).

[0067] Organic matter degradation occurred predominantly in the first reactor (ABR1 ), where solids settling, hydrolysis, fermentation, and methanogenesis were most active. Downstream chambers provided additional polishing but contributed less significantly to overall COD removal.

[0068] Despite effective organic matter removal, nitrogen removal was minimal under baseline anaerobic conditions (Figure 5). Ammonium concentrations increased from influent to ABR1 effluent due to mineralization of organic nitrogen via ammonification. Net ammonium concentrations increased by approximately 9% relative to influent concentrations. Nitrite and nitrate concentrations remained low throughout the system, indicating negligible nitrification in the absence of oxygen or electrochemical oxidation. Total dissolved nitrogen removal was therefore negligible during Example 1, demonstrating that conventional ABR operation without aeration or bioelectrochemical stimulation is insufficient to achieve significant nitrogen reduction.

[0069] Example 1 demonstrates that a multi-chamber anaerobic baffled reactor, operating without aeration and without applied electrical potential:

[0070] • Achieves substantial organic matter removal (-75% COD reduction);

[0071] • Maintains stable anaerobic digestion across staged chambers;

[0072] • Does not achieve meaningful total nitrogen removal;

[0073] • Produces net ammonium accumulation due to mineralization;

[0074] • Lacks sufficient redox potential to drive nitrification, denitrification, or anammox pathways.

[0075] Accordingly, this baseline configuration establishes the performance of a conventional ABR system and provides a direct comparison for subsequent examples incorporating aeration and / or bioelectrochemical stimulation.KPPB Ref: S94-09918.PCTExample 2: ABR with Intermittent Aeration

[0076] This example demonstrates that products of manufacture as provided herein are effective for enhanced organic matter oxidation and partial nitrogen transformation when operated as an anaerobic baffled reactor (ABR) with controlled intermittent aeration, without bioelectrochemical stimulation.

[0077] The exemplary reactor configuration was identical to that described in Example 1 , comprising two laboratory-scale acrylic anaerobic baffled reactors (ABR1 and ABR2) connected in series. Each reactor was divided into three chambers (A1C1-A1C3 and A2C1-A2C3) configured with alternating downflow and upflow hydraulic zones to promote staged anaerobic digestion and sludge blanket formation.

[0078] Intermittent aeration was integrated into the second ABR in the baffle between A2C1 and A2C2 to promote nitrification (without BES activity).

[0079] The combined working volume of the system was approximately 15.5 L. The reactors were maintained at temperatures ranging from approximately 15°C to 29°C. No bioelectrochemical electrodes, external circuitry, or applied electrical potential were present during this example.

[0080] In Example 2, controlled intermittent aeration was introduced into ABR2 (the downstream reactor). Aeration was applied intermittently using a timed cycle of approximately 10 minutes of aeration, followed by approximately 30 minutes without aeration. Aeration was localized to ABR2 to create an oxidizing environment in downstream chambers while maintaining primarily anaerobic conditions in ABR1. The influent wastewater composition was identical to that described in Example 1. The synthetic wastewater contained COD ranging from approximately 200 mg / L to 700 mg / L, and TDN ranging from approximately 30 mg N / L to 60 mg N / L. Organic carbon was supplied via a protein- and lipid-rich substrate. Ammonia nitrogen was supplemented to maintain a representative carbon-to-nitrogen ratio. The hydraulic loading regime during Example 2 was identical to the baseline Example 1 configuration: 1 hour pumping at approximately 0.83 L / h followed by 3 hours of rest. This regime simulated wastewater production from approximately a four-person household at full-scale equivalency.KPPB Ref: S94-09918.PCTExample 2 operation was conducted for approximately 114 days under steady-state conditions.

[0081] Water quality parameters were monitored weekly at the influent and each chamber (A1C1-A2C3). Samples were collected approximately one hour after completion of the feeding cycle to ensure stabilized conditions. Measured parameters included: pH, temperature, DO, TDS, EC, DOC, COD, TDN, ammonium, nitrite, and nitrate.

[0082] Dissolved oxygen concentrations increased in aerated ABR2 chambers during aeration intervals, while ABR1 remained predominantly anaerobic (Figure 2). Introduction of intermittent aeration significantly enhanced organic matter oxidation relative to the baseline anaerobic configuration of Example 1. Average COD removal from influent to the final chamber (A2C3) increased to approximately 93-94%, compared to approximately 75-76% removal during strictly anaerobic operation (Figure 4; Example 1 and Example 2, respectively).

[0083] Enhanced COD removal was attributed to increased aerobic and facultative microbial activity in ABR2, oxidation of residual biodegradable fractions, and improved breakdown of soluble organics in downstream chambers. Organic removal continued to occur primarily in ABR1, but additional polishing occurred in aerated ABR2.

[0084] Under intermittent aeration, ammonium concentrations increased initially in ABR1 due to ammonification of organic nitrogen. However, in ABR2, ammonium concentrations declined relative to ABR1, indicating partial nitrification. Nitrite (NO2’-N) and nitrate (NO3“-N) concentrations increased in aerated chambers, confirming that nitrification occurred in the presence of oxygen. Average nitrite concentrations were lower than nitrate concentrations, indicating progression toward nitrate formation under oxidizing conditions.

[0085] Despite nitrification occurring in ABR2, overall total dissolved nitrogen (TDN) removal remained limited because: i) no dedicated anoxic denitrification zone was provided downstream of aeration; ii) no electrochemical reduction pathways were present; and / or iii) limited carbon availability may have constrained denitrificationKPPB Ref: S94-09918.PCTefficiency. Thus, although nitrogen speciation shifted toward oxidized forms, complete nitrogen removal was not achieved.

[0086] This example demonstrates that intermittent aeration applied within a downstream anaerobic baffled reactor chamber: i) increases COD removal relative to strictly anaerobic operation; ii) promotes nitrification and conversion of ammonium to nitrite and nitrate; iii) does not achieve substantial total nitrogen removal in the absence of denitrification or electrochemical reduction; iv) establishes an oxidizing zone that can be strategically integrated with subsequent electrochemical or anoxic processes. Accordingly, this aeration-only configuration establishes the performance of an ABR with controlled oxygen introduction and provides a direct comparison for subsequent examples incorporating bioelectrochemical stimulation.Example 3: ABR Integrated with a BES Without Aeration

[0087] This example demonstrates that products of manufacture as provided herein are effective for enhanced organic matter degradation and nitrogen removal when operated as an electrified anaerobic baffled reactor (eABR) without aeration. The exemplary reactor configuration comprised two laboratory-scale acrylic anaerobic baffled reactors (ABR1 and ABR2) connected in series, each divided into three chambers (A1C1-A1C3 and A2C1-A2C3). Wastewater was directed beneath baffle walls and upward through sludge blanket regions to promote staged anaerobic digestion. The combined working volume of the system was approximately 15.5 L. Reactor temperatures ranged from approximately 15°C to 29°C. No aeration was applied during this example.

[0088] In Example 3, a bioelectrochemical system (BES) was integrated into ABR2 (the downstream reactor). An anode electrode was positioned between chambers A2C1 and A2C2, and a cathode electrode was positioned between chambers A2C2 and A2C3.

[0089] Each electrode comprised a high-surface-area conductive material suitable for electroactive biofilm formation. In certain embodiments, the electrodes comprised stainless steel mesh, metal mesh assemblies, carbon felt, carbon fiber, graphene-based materials, or combinations thereof.KPPB Ref: S94-09918.PCT

[0090] An Ag / AgCI reference electrode was positioned adjacent to each working electrode to enable electrochemical monitoring. The anode and cathode were connected to an external DC power supply capable of maintaining constant voltage or constant current operation.

[0091] During Example 3, voltage was maintained between approximately 0.5 V and 1.5 V across the electrodes. In certain operating periods, constant current operation of approximately 1.5 A was evaluated. No aeration was applied in any chamber during this example.

[0092] No zero-valent iron or nanoparticles were intentionally added during this example unless otherwise specified.

[0093] The influent wastewater composition was identical to that described in Examples 1 and 2, comprising:

[0094] • COD ranging from approximately 200 mg / L to 700 mg / L

[0095] • TDN ranging from approximately 30 mg N / L to 60 mg N / L

[0096] Organic carbon was supplied via a protein- and lipid-rich substrate. Ammonia nitrogen was supplemented to maintain a representative carbon-to-nitrogen ratio. The hydraulic regime remained:

[0097] • 1 hour pumping at approximately 0.83 L / h

[0098] • Followed by 3 hours of rest

[0099] Example 3 operation was conducted for approximately 326 days, allowing longterm evaluation of BES integration under baseline hydraulic loading.

[0100] Water quality parameters were monitored weekly at the influent and each chamber (A1C1-A2C3). Measurements included:

[0101] • Chemical oxygen demand (COD)

[0102] • Dissolved organic carbon (DOC)

[0103] • Total dissolved nitrogen (TDN)

[0104] • Ammonium (NH4+-N)

[0105] • Nitrite (NO2--N)

[0106] • Nitrate (NO3"-N)

[0107] • Dissolved oxygen (DO)KPPB Ref: S94-09918.PCT

[0108] • pH

[0109] • Electrical conductivity (EC)

[0110] • Total dissolved solids (TDS)

[0111] Samples were collected approximately one hour after completion of feeding cycles to ensure stabilized hydraulic conditions.

[0112] Integration of the BES into ABR2 resulted in high organic matter removal comparable to or exceeding aeration-only conditions. Average COD removal from influent to the final chamber (A2C3) was approximately 91-92%, demonstrating that electrodemediated redox processes enhanced degradation of residual organic compounds (Figure 4). Organic removal remained concentrated in ABR1 , but the electrified ABR2 contributed additional polishing through electrochemically stimulated microbial processes. DOC removal followed similar trends, with substantial removal occurring upstream and stabilization of residual soluble organic carbon in downstream chambers.

[0113] In contrast to Example 1 (baseline anaerobic) and Example 2 (aeration-only), the BES-only configuration resulted in substantial total dissolved nitrogen removal. Ammonium concentrations increased in ABR1 due to ammonification but declined significantly in ABR2 under electrified conditions. Overall TDN removal between A1C1 and A2C3 averaged approximately 55%. Nitrite and nitrate concentrations in the final effluent were lower than those observed in aeration-only conditions, indicating that electrochemical oxidation and reduction processes promoted nitrogen transformation beyond simple nitrification.

[0114] Electrochemical oxidation at the anode is believed to have facilitated partial ammonium oxidation and nitrite formation. Downstream reducing conditions at the cathode supported further reduction reactions and nitrogen gas formation through denitrification and / or anammox-associated pathways. Notably, the BES-only configuration avoided accumulation of high nitrate concentrations in the effluent, which may be advantageous for systems discharging to soils with shallow groundwater tables.

[0115] Under constant voltage operation, electrode potentials stabilized within a range conducive to electroactive biofilm activity. The anode potential fluctuated with substrate availability, while the applied cell potential maintained a consistent driving force for redoxKPPB Ref: S94-09918.PCTtransformations. No oxygen was detected in the system, confirming that nitrogen removal was achieved under strictly anaerobic and electrochemically mediated conditions.

[0116] This example demonstrates that integration of a bioelectrochemical system into a multi-chamber anaerobic baffled reactor:

[0117] • Maintains high organic matter removal (~92% COD removal);

[0118] • Achieves greater than 50% total dissolved nitrogen removal under strictly anaerobic conditions;

[0119] • Reduces ammonium concentrations without the need for aeration;

[0120] • Avoids excessive nitrate accumulation in effluent;

[0121] • Promotes sequential oxidation and reduction zones within baffled reactor geometry.

[0122] Accordingly, the BES-only configuration provides enhanced nitrogen removal relative to both baseline anaerobic operation and aeration-only operation, while maintaining low energy demand compared to fully aerobic treatment systems.Example 4: eABR with Bioelectrochemical Stimulation and Intermittent Aeration

[0123] This example demonstrates that products of manufacture as provided herein are effective for enhanced organic matter removal and substantially improved nitrogen removal when operated as an electrified anaerobic baffled reactor (ABR-BES) with controlled intermittent aeration.

[0124] The exemplary reactor configuration was identical to that described in Examples 1-3, comprising two laboratory-scale acrylic anaerobic baffled reactors (ABR1 and ABR2) connected in series, each divided into three chambers (A1C1-A1C3 and A2C1-A2C3). Wastewater flowed through alternating downflow and upflow zones to promote staged anaerobic digestion and sludge blanket development. The combined working volume of the system was approximately 15.5 L. Reactor temperatures ranged between approximately 15°C and 29°C.

[0125] In Example 4, a bioelectrochemical system (BES) was integrated into ABR2 (downstream reactor) as described in Example 3. An anode electrode was positioned between chambers A2C1 and A2C2, and a cathode electrode was positioned betweenKPPB Ref: S94-09918.PCTchambers A2C2 and A2C3. Electrodes comprised high-surface-area conductive material suitable for electroactive biofilm formation, including stainless steel mesh, metal mesh assemblies, carbon felt, carbon fiber, graphene-based materials, or combinations thereof. The electrodes were connected to an external DC power supply. During Example 4, voltage was maintained at approximately 1.5 V across the electrodes. An Ag / AgCI reference electrode was positioned adjacent to each working electrode to allow monitoring of electrode potentials.

[0126] In addition to electrical stimulation, controlled intermittent aeration was applied to ABR2. Aeration was introduced upstream of the anode region in ABR2 to create localized oxidizing conditions while maintaining predominantly anaerobic conditions in ABR1. Aeration was applied intermittently, allowing alternating oxidizing and reducing zones to develop within ABR2. This configuration created sequential:

[0127] • Oxidation zones (due to aeration and anodic processes), and

[0128] • Reduction zones (due to cathodic processes and downstream anoxic conditions).

[0129] The influent wastewater composition was consistent with prior examples, comprising:

[0130] • COD ranging from approximately 200 mg / L to 700 mg / L;

[0131] • Total dissolved nitrogen (TDN) ranging from approximately 30 mg N / L to 60 mg N / L.

[0132] Organic carbon was supplied via a protein- and lipid-rich substrate. Ammonia nitrogen was supplemented to achieve representative domestic wastewater carbon-to-nitrogen ratios. Example 4 operation was conducted for approximately 116 days under steady-state baseline hydraulic conditions.

[0133] Water quality parameters were monitored weekly at the influent and each chamber (A1C1-A2C3). Parameters included:

[0134] • Chemical oxygen demand (COD);

[0135] • Dissolved organic carbon (DOC);

[0136] • Total dissolved nitrogen (TDN);

[0137] • Ammonium (NH4+-N);KPPB Ref: S94-09918.PCT

[0138] • Nitrite (NO2"-N);

[0139] • Nitrate (NO3"-N);

[0140] • Dissolved oxygen (DO);

[0141] • pH;

[0142] • Electrical conductivity (EC);

[0143] • Total dissolved solids (TDS).

[0144] Samples were collected approximately one hour after feeding cycles to ensure stabilized hydraulic conditions.

[0145] The combined BES + aeration configuration maintained high organic matter removal. Average COD removal from influent to the final chamber (A2C3) was approximately 86-87%, comparable to or slightly lower than the BES-only configuration of Example 3 but significantly greater than the baseline anaerobic configuration of Example 1. The slight reduction relative to BES-only conditions is believed to be associated with increased biomass growth under aerated conditions, which may temporarily reduce soluble COD removal efficiency due to microbial proliferation. Nonetheless, effluent COD concentrations remained within ranges consistent with advanced onsite treatment performance.

[0146] The combined BES + aeration configuration produced the highest total dissolved nitrogen (TDN) removal observed under baseline hydraulic loading. Average TDN removal between A1C1 and A2C3 was approximately 70-72%, significantly higher than:

[0147] • Baseline anaerobic operation (Example 1);

[0148] • Aeration-only operation (Example 2); and

[0149] • BES-only operation (Example 3).

[0150] Ammonium removal also increased substantially, with removal efficiencies approaching approximately 75-80%. The improved nitrogen removal is attributed to the synergistic interaction of:

[0151] 1. Aeration-induced partial nitrification (NH4+— NO2“ / NO3“);

[0152] 2. Anodic electrochemical oxidation processes;

[0153] 3. Cathodic reduction processes;KPPB Ref: S94-09918.PCT

[0154] 4. Anoxic denitrification; and / or

[0155] 5. Potential anammox activity supported by sequential nitrite formation and reducing environments.

[0156] Unlike aeration-only operation, nitrate accumulation in the effluent was reduced due to the presence of electrochemically driven reduction zones downstream of aeration.

[0157] The combination of intermittent aeration and applied electrical potential created dynamic redox stratification within ABR2:

[0158] • Upstream oxidizing microenvironments near aeration and anode regions;

[0159] • Downstream reducing microenvironments near the cathode;

[0160] • Alternating oxic-anoxic interfaces conducive to complete nitrogen cycling.

[0161] This spatial redox distribution was enabled by the baffled reactor geometry and electrode placement.

[0162] This example demonstrates that integrating intermittent aeration with bioelectrochemical stimulation within a multi-chamber anaerobic baffled reactor:

[0163] • Achieves high COD removal (-87%);

[0164] • Achieves total dissolved nitrogen removal exceeding 70%;

[0165] • Substantially increases ammonium removal;

[0166] • Reduces nitrate accumulation relative to aeration-only systems.Example 5: eABR with BES and Aeration Under Increased Hydraulic Loading

[0167] This example demonstrates that products of manufacture as provided herein are effective for organic matter removal and nitrogen transformation when operated as an electrified anaerobic baffled reactor (ABR-BES) with controlled intermittent aeration under elevated hydraulic loading conditions representative of household overloading.

[0168] The exemplary reactor configuration was identical to that described in Examples 1-4, comprising two laboratory-scale acrylic anaerobic baffled reactors (ABR1 and ABR2) connected in series, each divided into three chambers (A1C1-A1C3 and A2C1-A2C3). Wastewater flowed through alternating downflow and upflow zones to promote staged digestion and biomass retention. The combined working volume of theKPPB Ref: S94-09918.PCTsystem was approximately 15.5 L. Reactor temperatures ranged between approximately 15°C and 29°C.

[0169] In Example 5, the bioelectrochemical system (BES) remained integrated into ABR2 as described in Example 3. An anode was positioned between A2C1 and A2C2, and a cathode was positioned between A2C2 and A2C3. Electrodes comprised high-surface-area conductive material capable of supporting electroactive biofilm formation. An external DC power supply maintained an applied voltage of approximately 1.5 V across the electrodes during pumping intervals. Controlled intermittent aeration was applied to ABR2 during pumping cycles. Aeration was synchronized with influent flow periods to create transient oxidizing conditions while preserving predominantly anaerobic conditions during rest intervals.

[0170] In Example 5, the system was operated under increased hydraulic loading to simulate high water use scenarios (e.g., approximately six-person household loading conditions). The feeding regime was modified as follows:

[0171] • 4 hours pumping at approximately 1.25 L / h;

[0172] • 4 hours rest;

[0173] • 4 hours pumping at approximately 1.25 L / h;

[0174] • Followed by 12 hours rest.

[0175] This regime increased volumetric throughput and reduced hydraulic retention time relative to baseline Examples 1-4. Example 5 operation was conducted for approximately 50 days.

[0176] The influent wastewater composition was consistent with prior examples of COD ranging from approximately 200 mg / L to 700 mg / L, and TDN ranging from approximately 30 mg N / L to 60 mg N / L. Organic carbon was supplied via a protein- and lipid-rich substrate, and ammonia nitrogen was supplemented to maintain representative carbon-to-nitrogen ratios.

[0177] Water quality parameters were monitored at influent and each chamber location (A1C1-A2C3), including: COD; sCOD, DOC (Figure 5), TDN, Ammonium (NH4+-N), Nitrite (NO2“-N), Nitrate (NO3"-N), Dissolved oxygen (DO), pH, Electrical conductivity (EC), and Total dissolved solids (TDS). In addition, methanogenic activity was evaluatedKPPB Ref: S94-09918.PCTusing fluorescence monitoring of coenzyme F420 as an indicator of active methanogenic Archaea. Samples were collected after stabilization following pumping cycles.

[0178] Despite elevated hydraulic loading and reduced retention time, high COD removal was maintained. Average COD removal from influent to the final chamber (A2C3) exceeded approximately 90%. Soluble COD (sCOD) removal averaged approximately 70%, demonstrating effective degradation of soluble organic fractions even under high flow conditions. DOC removal efficiency decreased relative to baseline Examples 3-4, which may be attributed to reduced reaction time due to higher flow rates; potential sludge accumulation after extended operation; and / or increased hydraulic shear effects. Nonetheless, effluent COD concentrations remained within ranges associated with advanced onsite treatment performance.

[0179] Total dissolved nitrogen (TDN) removal under Example 5 conditions averaged approximately 35-40%, lower than Example 4 baseline hydraulic operation. Ammonium removal remained substantial (approximately 70%), indicating continued oxidation and transformation of NH4+. However, nitrate concentrations in the effluent were elevated relative to BES-only operation under high flow conditions, suggesting that intermittent aeration promoted nitrification without complete downstream reduction during shortened hydraulic residence times. The combination of increased flow and aeration may have limited the duration of reducing conditions necessary for complete denitrification or electrochemical nitrate reduction.

[0180] Fluorescence monitoring detected F420 peaks characteristic of methanogenic activity, particularly in upstream chambers. Methanogenic signatures were strongest in ABR1, where COD removal was most significant. This result indicates that methane production continued under high-flow BES and aeration operation, although gas capture was not the primary focus of this Example.

[0181] After approximately 745 days of cumulative operation prior to and during Example 5, visual observation indicated sludge and scum accumulation within chambers.

[0182] Despite this extended operation without maintenance, the system maintained high COD removal and moderate nitrogen removal under increased hydraulicstress. ThisKPPB Ref: S94-09918.PCTdemonstrates that the electrified ABR configuration can tolerate hydraulic overloading while maintaining functional performance.

[0183] This example demonstrates that an electrified anaerobic baffled reactor with intermittent aeration:

[0184] • Maintains COD removal exceeding 90% under elevated hydraulic loading;

[0185] • Sustains substantial ammonium removal;

[0186] • Achieves moderate total nitrogen removal under reduced retention time;

[0187] • Continues to support methanogenic activity;

[0188] • Maintains operational stability despite long-term sludge accumulation.

[0189] Accordingly, the BES + aeration configuration provides resilient organic matter removal and partial nitrogen control under conditions simulating household overloading.Example: 6: eARB Under Increased Hydraulic Loading Without Aeration

[0190] This example demonstrates that products of manufacture as provided herein are effective for organic matter removal and nitrogen removal when operated as an electrified anaerobic baffled reactor (ABR-BES) under elevated hydraulic loading conditions and in the absence of aeration.

[0191] The exemplary reactor configuration was identical to that described in Examples 1-5, comprising two laboratory-scale acrylic anaerobic baffled reactors (ABR1 and ABR2) connected in series, each divided into three chambers (A1C1-A1C3 and A2C1-A2C3). Wastewater flowed through alternating downflow and upflow zones to promote solids retention and staged biological treatment. The combined working volume of the system was approximately 15.5 L. Reactor temperatures ranged between approximately 15°C and 29°C.

[0192] In Example 6, the bioelectrochemical system (BES) remained integrated within ABR2 as described in Example 3. An anode electrode was positioned between chambers A2C1 and A2C2, and a cathode electrode was positioned between chambers A2C2 and A2C3. The electrodes comprised high-surface-area conductive materials capable of supporting electroactive biofilm formation.KPPB Ref: S94-09918.PCT

[0193] An external DC power supply maintained an applied voltage of approximately 1.5 V across the electrodes.

[0194] Unlike Example 5, no aeration was applied in any chamber during Example 6. The system therefore operated under strictly anaerobic, electrochemically stimulated conditions.

[0195] The hydraulic regime during Example 6 was identical to Example 5 and simulated high water use or overloading conditions:

[0196] • 4 hours pumping at approximately 1.25 L / h;

[0197] • 4 hours rest;

[0198] • 4 hours pumping at approximately 1.25 L / h;

[0199] • Followed by 12 hours rest.

[0200] This configuration increased volumetric throughput and reduced hydraulic retention time relative to baseline conditions (Examples 1-4). Example 6 operation was conducted for approximately 36 days.

[0201] The influent wastewater composition remained consistent with prior examples, comprising:

[0202] • COD ranging from approximately 200 mg / L to 700 mg / L;

[0203] • Total dissolved nitrogen (TDN) ranging from approximately 30 mg N / L to 60 mg N / L.

[0204] Organic carbon was supplied via a protein- and lipid-rich substrate, and ammonia nitrogen was supplemented to represent typical domestic wastewater composition.

[0205] Water quality parameters were monitored at influent and chamber locations (A1C1-A2C3), including:

[0206] • COD;

[0207] • Soluble COD (sCOD);

[0208] • DOC;

[0209] • TDN;

[0210] • Ammonium (NH4+-N);

[0211] • Nitrite (NO2--N);KPPB Ref: S94-09918.PCT

[0212] • Nitrate (NO3--N);

[0213] • pH;

[0214] • Electrical conductivity (EC);

[0215] • Total dissolved solids (TDS).

[0216] Methanogenic activity was evaluated via fluorescence detection of coenzyme F420 as an indicator of active methanogenic Archaea. Samples were collected following stabilization after pumping cycles.

[0217] Under elevated hydraulic loading and without aeration, COD removal decreased relative to Example 5 but remained substantial. Average COD removal from influent to the final chamber (A2C3) was approximately 75-76%, comparable to the strictly anaerobic baseline of Example 1 but achieved under significantly higher flow rates. Soluble COD and DOC removal efficiencies were lower than those observed during baseline BES operation (Example 3), likely due to reduced hydraulic retention time and extended system operation without sludge removal. Nonetheless, effluent COD concentrations remained within ranges approaching regulatory performance targets for decentralized systems.

[0218] Total dissolved nitrogen (TDN) removal during Example 6 averaged approximately 55-60%, exceeding the >50% nitrogen reduction benchmark associated with NSF performance criteria. Ammonium removal remained high (approximately 65-70%), despite the absence of aeration. Importantly, nitrate concentrations in the effluent were substantially lower than those observed during Example 5 (BES + aeration under high flow). This indicates that the absence of oxygen limited nitrification-driven nitrate accumulation and allowed more effective downstream electrochemical and biological reduction pathways to proceed.

[0219] The BES-only configuration under high flow therefore produced:

[0220] • Moderate COD removal;

[0221] • High ammonium removal;

[0222] • Total nitrogen removal exceeding 50%;

[0223] • Reduced effluent nitrate accumulation relative to aerated high-flow operation.KPPB Ref: S94-09918.PCT

[0224] Fluorescence monitoring indicated the presence of F420-associated peaks consistent with active methanogenic communities, particularly in ABR1 and downstream reducing chambers. The persistence of methanogenic signatures under high hydraulic loading demonstrates that electrochemically stimulated anaerobic conditions can maintain functional microbial communities even during hydraulic stress.

[0225] Comparison of Examples 5 and 6 under identical high-flow conditions demonstrated that:

[0226] • BES + aeration (Example 5) maintained higher COD removal;

[0227] • BES-only (Example 6) achieved greater total nitrogen removal;

[0228] • BES-only produced lower nitrate accumulation in effluent;

[0229] • Both configurations maintained functional performance despite reduced retention time and prolonged system operation.

[0230] This example demonstrates that an electrified anaerobic baffled reactor operated without aeration under elevated hydraulic loading:

[0231] • Maintains substantial organic matter removal (-75% COD removal);

[0232] • Achieves total nitrogen removal exceeding 50%;

[0233] • Reduces ammonium without aeration;

[0234] • Limits nitrate accumulation relative to aerated configurations;

[0235] • Supports methanogenic activity under hydraulic stress.

[0236] Accordingly, the BES-only configuration provides a lower-energy alternative to aerated systems while meeting nitrogen reduction benchmarks, even under simulated household overloading conditions.DOCTRINE OF EQUIVALENTS

[0237] This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in variousKPPB Ref: S94-09918.PCTembodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims.

[0238] As used herein, the singular terms “a,” “an,” and “the,” may include plural referents unless the context clearly dictates otherwise. Reference to an object in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.”

[0239] As used herein, the terms “approximately” and “about” are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. When used in conjunction with a numerical value, the terms can refer to a range of variation of less than or equal to ± 10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1 %, less than or equal to ±0.5%, less than or equal to ±0.1 %, or less than or equal to ±0.05%.

[0240] Additionally, amounts, ratios, and other numerical values may sometimes be presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood flexibly to include numerical values explicitly specified as limits of a range, but also to include all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified. Where ranges are described, the range should be understood to include the endpoints of the ranges, and the endpoints of such ranges are also contemplated to stand on their own as inventive, individual data points and to form the endpoints of other ranges. For example, a ratio in the range of about 1 to about 200 should be understood to include the explicitly recited limits of about 1 and about 200, but also to include individual ratios such as about 2, about 3, and about 4, sub-ranges such as about 1 to about 10, about 10 to about 50, about 20 to about 100, about 100 to about 200, and so forth, and related ranges such as greater than about 1 or less than about 200.

Claims

KPPB Ref: S94-09918.PCTWHAT IS CLAIMED IS:

1. A wastewater treatment system comprising one or more anaerobic baffled reactors wherein the one or more anaerobic baffled reactors comprises a bioelectrochemical system with one or more anaerobic baffled reactors.

2. The wastewater treatment system of claim 1 , wherein the one or more anaerobic baffled reactors further comprises one or more chambers.

3. The wastewater treatment system of claim 2, wherein intermittent aeration is applied to the one or more chambers.

4. The wastewater treatment system of claim 2, wherein the one or more chambers comprise zero valent iron.

5. The wastewater treatment system of claim 2, wherein one or more chambers comprise an aeration supplement.

6. The wastewater treatment system of claim 5, wherein the aeration supplement is one or more rocks.

7. The wastewater treatment system of claim 1, further comprising a multi-chamber anaerobic baffle reactor comprising four or more chambers; wherein the four or more chambers are in series.KPPB Ref: S94-09918.PCT8. The wastewater treatment system of claim 1 , wherein the one or more anerobic baffle reactor comprises:an anode;a cathode, wherein the cathode is surrounded by a conductive material; and two or more baffle walls, wherein the anode and the cathode are placed between the two or more baffle walls;wherein the anode and the cathode are in electrical connection.

9. The wastewater treatment system of claim 8, wherein the conductive material is a conductive mesh.

10. The wastewater treatment system of claim 8, wherein the anode and the cathode are connected by an external circuit; wherein an external potential is applied to the external circuit.

11. A method of wastewater treatment comprising:providing wastewater to a wastewater treatment system comprising one or more anaerobic baffled reactors;wherein the one or more anaerobic baffled reactors comprises a bioelectrochemical system with one or more anaerobic baffled reactors;wherein the one or more anerobic baffle reactor comprises:an anode;a cathode, wherein the cathode is surrounded by a conductive material; andtwo or more baffle walls, wherein the anode and the cathode are placed between the two or more baffle walls;wherein the anode and the cathode are in electrical connection; and applying at least one of a voltage or a current to the anode and the cathode.KPPB Ref: S94-09918.PCT12. The method of claim 11 , wherein the conductive material is a conductive mesh.

13. The method of claim 12, wherein the conductive mesh is at least one of stainless steel or carbon felt.

14. The method of claim 11, wherein the anode and the cathode are connected by an external circuit.

15. The method of claim 11 , wherein the step applying at least one of the voltage or current initiates an electrochemical reaction within the biochemical system.

16. The method of claim 11 , wherein the one or more anaerobic baffled reactors further comprises one or more chambers.

17. The method of claim 16, wherein one or more chambers comprise an aeration supplement.

18. The method of claim 17, wherein the aeration supplement is one or more rocks.

19. The method of claim 11, further comprising a multi-chamber anaerobic baffle reactor comprising four or more chambers.

20. The method of claim 19, wherein the four or more chambers are in series.

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