System and method for reducing greenhouse gas emissions from wastewater reservoirs using vermifiltration

Abstract

The invention relates to a system and method for reducing greenhouse gas emissions from wastewater reservoirs using a vermifiltration system. The method comprises introducing organic wastewater into a vermifiltration unit, distributing the wastewater over a biological filter bed containing earthworms, collecting the treated effluent, and channeling it into a wastewater reservoir. The system reduces methane, carbon dioxide, and ammonia emissions by minimizing anaerobic decomposition at the reservoir surface. The vermifiltration unit can be connected upstream or downstream of the reservoir. Optional features include real-time monitoring, emission factor calibration, odor control, and vermicompost recovery. The invention also includes a method for generating carbon credits based on verified emission reductions, which can be tokenized and traded. Field studies demonstrate significant reductions in greenhouse gas emissions and nutrient loads, including total nitrogen, ammoniacal nitrogen, nitrate, and phosphorus. The invention offers a low-energy, scalable solution combining waste treatment, climate mitigation, and circular resource recovery.

Description

SYSTEM AND METHOD FOR REDUCING GREENHOUSE GAS EMISSIONS FROM WASTEWATER RESERVOIRS USING VERMIFILTRATION

[0001] The present invention relates to the field of wastewater treatment and greenhouse gas emission mitigation. More specifically, it pertains to a system and method for reducing methane, carbon dioxide, and ammonia emissions from wastewater reservoirs by treating organic waste through vermifiltration.

[0002] The invention may be applied in diverse contexts where organic matter in wastewater is stored in lagoons or holding ponds, such as in dairy farming, wineries, fruit and / or vegetable processing facilities, milk processing facilities, sewage treatment facilities, industrial food processing, slaughterhouses, or beverage production. Depending on the sector, the relevant indicators of organic load may include volatile solids, biochemical oxygen demand (BOD), or chemical oxygen demand (COD), all of which contribute to anaerobic degradation and associated greenhouse gas emissions. The system described herein is suitable for mitigating these emissions regardless of the specific industry.

[0003] Greenhouse gases (GHGs) such as methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) play a significant role in climate change due to their heat-trapping properties. A major source of GHG emissions is the decomposition of organic waste in wastewater reservoirs, particularly those associated with agriculture, food processing, and livestock operations. Anaerobic lagoons and similar storage structures emit large volumes of methane and ammonia as organic matter breaks down in the absence of oxygen.

[0004] Conventional treatment systems often fail to fully eliminate the volatile solids and nutrient loads responsible for these emissions. Moreover, many of these approaches require significant energy inputs, produce residual sludge, or involve chemical additives that can pose environmental risks.

[0005] Vermifiltration offers a sustainable, low-energy alternative for the aerobic treatment of organic wastewater. By leveraging the natural digestive processes of earthworms and associated microbial communities, vermifiltration systems can significantly reduce the concentration of organic pollutants and nutrients in wastewater. These systems produce a nutrient-rich byproduct (vermicompost) while minimizing the generation of methane and other greenhouse gases.

[0006] While vermifiltration has been previously used in wastewater treatment, its direct application for mitigating surface emissions from wastewater reservoirs—and its integration into carbon credit frameworks—remains a novel approach. The present invention provides a system and method that not only treats wastewater of storage reservoirs but also quantifies and monetizes the environmental benefits through verified reductions in greenhouse gas emissions.

[0007] The present invention provides a system and method for reducing greenhouse gas emissions from wastewater reservoirs by utilizing a vermifiltration process. The system employs one or more vermifiltration beds containing earthworms and organic filtration media configured to degrade organic matter aerobically. This process significantly reduces methane (CH₄), carbon dioxide (CO₂), and ammonia (NH₃) emissions from wastewater, especially in applications such as dairy farms, food processing facilities, and other operations that generate high-strength organic effluents.

[0008] In one embodiment, the vermifiltration system is installed upstream of a wastewater reservoir, treating the inflow before it enters the reservoir. In another embodiment, the system is installed downstream, drawing effluent from the bottom of the reservoir and recirculating it—after treatment—to the surface or to another storage unit. In either configuration, the system reduces the emission potential of the reservoir by minimizing the organic load and preventing anaerobic decomposition at the surface.

[0009] In practice, the upstream configuration—where wastewater is treated before entering the reservoir—is particularly advantageous for reducing greenhouse gas emissions from the reservoir. By intercepting volatile solids prior to anaerobic storage, this approach directly prevents the formation of methane in long-term holding lagoons. While the downstream configuration may still reduce surface emissions through recirculation of treated wastewater to the surface of the reservoir, its performance might be limited in comparison with the upstream configuration. Nevertheless, both configurations remain technically viable depending on the site-specific objectives.

[0010] The system optionally incorporates features such as real-time gas monitoring, emission factor calibration, nutrient recovery, odor control, and vermicompost harvesting. These additional features enhance the overall environmental and operational performance of the system.

[0011] The invention further provides a method for integrating vermifiltration into carbon credit frameworks. By establishing a baseline emission profile, implementing vermifiltration, and continuously verifying the emission reductions achieved, users may generate carbon credits. These credits can be tokenized and traded on carbon markets, creating economic incentives for adopting the technology. The system thus supports both environmental and financial sustainability.

[0012] Open-air wastewater reservoirs, particularly those associated with agriculture and livestock operations, emit significant amounts of methane, carbon dioxide, and ammonia due to anaerobic decomposition of organic matter. Conventional mitigation strategies, such as covered lagoons or chemical treatments, often require high capital investment, continuous energy input, or generate undesirable byproducts such as sludge. Additionally, these methods typically do not integrate with carbon crediting mechanisms or provide co-benefits like nutrient recovery. There is a need for a low-energy, scalable, and verifiable solution capable of reducing greenhouse gas emissions from wastewater storage systems while enabling resource recovery and participation in environmental markets.

[0013] The invention provides a system and method for reducing greenhouse gas emissions from wastewater reservoirs using vermifiltration. Wastewater containing organic matter is treated aerobically as it passes through a biological filtration bed populated by earthworms and microorganisms. This process reduces the concentration of volatile solids and nutrients, limiting anaerobic decomposition and the associated emission of methane, carbon dioxide, and ammonia from the reservoir. The system can be implemented upstream or downstream of existing reservoirs and may include modules for real-time monitoring, emission coefficient calibration, nutrient recovery, odor control, and blockchain-based carbon credit generation. Field results demonstrate high effectiveness in removing nitrogen compounds and reducing gas emissions.

[0014] The invention offers multiple advantages over conventional wastewater treatment and emission mitigation systems:Significant reduction of greenhouse gas emissions, including methane (97–100%), carbon dioxide (60–85%), and ammonia (84–110%), as measured from dairy wastewater reservoirs.Effective removal of nutrients such as total nitrogen (63–91%), ammoniacal nitrogen (70–90%), nitrate (60–86%), and phosphorus (27–57%).Generation of vermicompost, a nutrient-rich byproduct suitable for use in agriculture and carbon sequestration. When applied to soils, this material contributes to long-term carbon sequestration, providing an additional pathway for greenhouse gas mitigation beyond the treatment phase.The vermicompost also enables nutrient recovery, as a portion of the nitrogen and phosphorus originally present in the wastewater is retained in a stabilized, agriculturally beneficial form.Lower capital and operating costs compared to mechanical or chemical alternatives.Compatibility with both new and existing reservoir infrastructures.Enabling participation in carbon credit programs through measurable, verifiable emission reductions, which may be tokenized and traded.Additional environmental benefits including odor reduction, improved effluent quality, pathogen reduction, and lower nitrous oxide emissions from irrigated land.Observed co-benefits in certain installations include improved cow health indicators, such as lower incidence of mastitis, potentially linked to reduced odor and vector presence.By lowering the nutrient concentration in effluent, the system may also reduce the total land area required for field application, facilitating compliance with nutrient management regulations based on nitrogen and phosphorus limits per acre.

[0015] The accompanying figures are provided for illustrative purposes only and are not intended to limit the scope of the invention in any way. They represent exemplary configurations and test results that help to explain the principles and benefits of the invention.Fig.1

[0016] illustrates the concentrations of total nitrogen (TN) in influent and effluent from the Vermifilter, and the corresponding percentage reduction by the system.Fig.2

[0017] illustrates the concentrations of total ammoniacal nitrogen (TAN) in influent and effluent from the Vermifilter, and the corresponding percentage reduction by the system.Fig.3

[0018] illustrates the concentrations of nitrate nitrogen (NO3-N) in influent and effluent from the Vermifilter, and the corresponding percentage reduction by the system.Fig.4

[0019] illustrates the concentrations of total phosphorus (TP) in influent and effluent from the Vermifilter, and the corresponding percentage reduction by the system.Fig.5

[0020] illustrates a schematic diagram of the custom-made test chamber and instrumentation used for field studies of air emissions.Fig.6

[0021] illustrates the methane emission rates at the inlet and outlet of the Vermifilter system, and the corresponding percentage reduction in methane emissions.Fig.7

[0022] illustrates the carbon dioxide emission rates at the inlet and outlet of the Vermifilter system, and the corresponding percentage reduction in CO₂ emissions.Fig.8

[0023] illustrates the ammonia emission rates at the inlet and outlet of the Vermifilter system, and the corresponding percentage reduction in ammonia emissions.

[0024] The present invention provides a system and method for reducing greenhouse gas (GHG) emissions from wastewater reservoirs through vermifiltration. Vermifiltration is a biological filtration process employing earthworms and associated aerobic microbial communities to treat organic waste in fluid streams. This system minimizes anaerobic decomposition, thereby reducing the emission of methane (CH₄), carbon dioxide (CO₂), and ammonia (NH₃), which are among the most significant GHGs emitted from traditional manure and wastewater management systems.

[0025] The invention aims to prevent direct GHG emissions from organic sources by integrating vermifiltration in wastewater systems. The proposed system is particularly suited for manure management in agriculture, where untreated wastewater stored in open reservoirs is a major source of methane emissions.

[0026] The vermifiltration system comprises at least one filtration bed with a multilayered organic medium populated by earthworms. The bed is connected by fluid conduits to at least one wastewater reservoir, and its placement relative to the reservoir can follow two main configurations:Upstream Configuration: In the preferred embodiment the system is positioned before the reservoir. Untreated wastewater is diverted from its original path and fed directly into the vermifiltration system. The treated effluent is then channeled into the reservoir, effectively converting it into a storage facility for treated water.Downstream Configuration: Alternatively, the system is connected after the reservoir. Wastewater is extracted from the bottom of the reservoir, treated through vermifiltration, and returned—preferably to the surface of the reservoir—or directed to a separate storage location. This arrangement is useful when retrofitting existing installations.

[0027] In either configuration, the vermifiltration system prevents anaerobic zones from forming at the surface of the reservoir by replacing untreated wastewater with effluent low in organic content. This significantly reduces or prevents surface GHG emissions. While both upstream and downstream configurations may be implemented depending on site conditions, the upstream configuration is preferred for carbon credit generation purposes, as it ensures that the volatile solids responsible for methane emissions are treated prior to entering the storage reservoir. This prevents anaerobic degradation in the reservoir, which is the principal source of methane emissions in conventional systems.

[0028] In all implementations, the vermifiltration system is operatively connected to at least one wastewater reservoir. In an upstream configuration, untreated wastewater is diverted to the vermifiltration unit prior to entering the reservoir. In a downstream configuration, the system draws partially treated water from the bottom of the reservoir, processes it through the vermifiltration unit, and returns the treated effluent to the surface of the same reservoir or to a separate holding facility. In both cases, the connection between the vermifiltration unit and the reservoir is essential for achieving the emission reduction goals of the invention.

[0029] The system includes a distribution mechanism, such as spray nozzles or drip lines, to ensure even dispersion of wastewater over the biological filter bed. An effluent collection system at the base of the bed gathers the treated water and channels it toward the reservoir. Optional components include real-time monitoring sensors for pH, temperature, total suspended solids (TSS), oxygen levels, and methane concentration. In some embodiments, the vermifiltration units are designed in modular form to allow operational flexibility, scalability, and ease of maintenance.

[0030] The system may further include additional modules that enhance performance:Real-Time Monitoring: The system may incorporate sensors for continuous measurement of methane flux, oxygen levels, temperature, and other relevant parameters, allowing dynamic optimization.Emission Coefficient Calibration: Periodic recalibration of the methane emission coefficient ensures that the system's performance aligns with actual reductions, improving reporting accuracy.Co-Benefit Optimization: In addition to GHG mitigation, the system enables removal of nutrients such as nitrogen and phosphorus, as well as salts and suspended solids, enhancing effluent quality and producing a valuable vermicompost byproduct.Odor Control: The system may include odor management features to improve local environmental conditions.

[0031] The byproduct of the vermifiltration process—vermicompost—retains a significant portion of the carbon and nutrients originally present in the wastewater. This material can be used for soil restoration or as an organic fertilizer, contributing to carbon sequestration and circular agriculture. In certain applications, the treated effluent may also exhibit reduced pathogen concentrations, enabling safe reuse in irrigation or controlled discharge. Additionally, the reduction in nitrogen load achieved through vermifiltration may result in lower nitrous oxide (N₂O) emissions when the treated water is applied to agricultural fields.

[0032] The invention also enables integration into carbon crediting frameworks, such as those administered under the American Carbon Registry (ACR), Climate Action Reserve (CAR), or Gold Standard. A facility may establish a baseline for emissions and quantify the reductions achieved via vermifiltration. Verified emission reductions (typically expressed in metric tons of CO₂ equivalent) can be converted into carbon credits and monetized.

[0033] Participation in carbon credit systems involves:Baseline Determination: Establishing the emissions that would occur in the absence of the vermifiltration system.Monitoring and Verification: Tracking system performance and verifying emission reductions through independent third-party validation.Credit Generation and Trading: Issuing credits based on verified reductions and participating in carbon markets through insetting or offsetting.

[0034] In an insetting model, a dairy farm may implement vermifiltration internally and claim the associated credits to meet sustainability goals. In an offsetting scenario, third parties—such as dairy processors—may invest in external vermifiltration projects and acquire the credits.

[0035] The system may also be integrated with blockchain-based ecosystems for carbon credit generation and trading. Blockchain enables:Transparent and immutable tracking of emission reductions.Traceable and verifiable tokenization of carbon credits.Fraud prevention and elimination of double-counting.Smart contract automation for credit issuance and transfer.

[0036] Through tokenization, each ton of CO₂-equivalent reduction achieved via vermifiltration can be represented as a unique digital asset, enabling seamless and secure exchange in decentralized markets.

[0037] The token ecosystem may involve multiple stakeholders, including project developers, dairy farms, wastewater processors, carbon verifiers, and sustainability-focused organizations. These participants can interact within a decentralized system to issue, verify, and exchange digital carbon assets in a secure and transparent manner.

[0038] In certain embodiments, at least part of the method for generating, verifying, and exchanging carbon credits may be implemented by a computer program product comprising instructions stored on a non-transitory computer-readable medium. When executed by a processor, the instructions may enable the system to collect data from sensors associated with the vermifiltration process, calculate greenhouse gas reductions relative to a baseline, trigger the issuance of tokenized credits via smart contracts, and register transactions in a distributed ledger. Such implementations may further provide user interfaces for project owners, verifiers, and credit buyers, allowing interaction with the system via authenticated nodes. These digital processes enhance transparency, scalability, and automation in the administration of the vermifiltration-based carbon crediting framework.

[0039] Preferred Implementations

[0040] The following implementations illustrate preferred ways in which the invention may be practiced. They describe representative configurations and sequences of operation that correspond to particular aspects of the invention as described above.

[0041] In one preferred implementation, wastewater containing organic matter is introduced into a vermifiltration system, where it is distributed over a biological filter bed populated with earthworms. The treated effluent is collected and channeled into a wastewater reservoir. By reducing the organic load of the water entering the reservoir, greenhouse gas emissions—especially methane, carbon dioxide, and ammonia—are minimized.

[0042] In another implementation, the vermifiltration system is positioned upstream of the reservoir, intercepting the wastewater before storage. Alternatively, the system may be placed downstream, drawing untreated wastewater from the bottom of the reservoir and reintroducing the treated effluent at the surface of the reservoir or into another storage tank.

[0043] In yet another implementation, the system includes real-time monitoring devices to measure gas emissions and system performance parameters such as oxygen levels, temperature, flow rates, pH, and total suspended solids (TSS). These readings may be used to adjust system operation dynamically for optimal efficiency.

[0044] A further implementation involves the recovery of vermicompost produced by the biological action of the earthworms. This nutrient-rich byproduct can be collected periodically and used for soil improvement or carbon sequestration.

[0045] In a different implementation, the vermifiltration system is deployed as part of a greenhouse gas mitigation and carbon crediting strategy. A baseline emission profile is established, and the performance of the system is monitored and verified. Emission reductions are quantified and converted into carbon credits.

[0046] In some implementations, reductions in nitrogen concentration in the treated effluent lead to lower nitrous oxide emissions when the effluent is used for land irrigation, providing additional environmental value.

[0047] Another implementation includes the tokenization of carbon credits through a blockchain infrastructure. Smart contracts are employed to automate the issuance and retirement of digital credits based on verified emission reductions.

[0048] The platform may support both insetting strategies—where the benefits are retained within a company’s own operations—and offsetting strategies, where credits are sold to external entities aiming to compensate for their emissions.Examples

[0049] The following examples are provided solely for the purpose of illustrating specific embodiments of the invention and demonstrating its technical effectiveness. They are not intended to limit the scope of the invention, which is defined by the claims. Variations and equivalents will be apparent to those skilled in the art.

[0050] Example 1 - Nutrient Removal

[0051] To evaluate the nutrient removal performance of the vermifiltration system, a study was conducted over a six-month period at a dairy wastewater treatment site. Samples were collected at both the inlet (influent) and outlet (effluent) of the system at least every two weeks. Standard analytical methods based on APHA protocols (1998, 2005) were used to assess nutrient concentrations.illustrates the concentrations of total nitrogen (TN) in influent and effluent from the Vermifilter, and the corresponding percentage reduction by the system. The TN removal efficiencies ranged from 63% to 91%.illustrates the concentrations of total ammoniacal nitrogen (TAN) in influent and effluent. The TAN removal efficiencies ranged from 70% to 90%.illustrates the concentrations of nitrate nitrogen (NO₃-N) in influent and effluent. Removal efficiencies ranged from 60% to 86%. Variability in influent levels was observed due to the recycling of treated effluent into the influent stream.illustrates the concentrations of total phosphorus (TP) in influent and effluent. Removal efficiencies ranged from 27% to 57%.

[0052] These results confirm that the system significantly reduces the nutrient load in wastewater, supporting its application in nutrient-sensitive environments and for water reuse.

[0053] Example 2 - Emission Reduction

[0054] A field study was also conducted to assess the potential for air emission reductions using the vermifiltration system. Emissions of methane (CH₄), carbon dioxide (CO₂), and ammonia (NH₃) were measured using custom-built dynamic chambers and a photoacoustic infrared analyzer (Model 1412, Innova AirTech Instruments). Gas concentrations were sampled from the chamber headspace and calculated using standard flux measurement protocols.illustrates the schematic diagram of the custom test chamber and instrumentation setup used during the field studies.illustrates methane emission rates at the inlet and outlet of the Vermifilter system. Methane emissions were reduced by 97% to 100% across 11 sampling events.illustrates carbon dioxide emission rates before and after vermifiltration treatment, with reductions ranging from 60% to 85%.illustrates ammonia emission rates at the inlet and outlet, with emission reductions ranging from 84% to 110%. In many cases, emissions from treated effluent were undetectable.

[0055] These experimental findings demonstrate the substantial environmental benefit of the system, not only in terms of nutrient recovery but also in greenhouse gas mitigation. Additionally, the use of treated effluent with lower nitrogen concentrations may reduce indirect nitrous oxide (N₂O) emissions associated with land application, further enhancing the climate benefits of the system.

Claims

A method for reducing greenhouse gas emissions from a wastewater reservoir using a vermifiltration system, the method comprising:introducing wastewater containing organic waste into a vermifiltration system;distributing the wastewater over the vermifiltration system to initiate aerobic biological treatment;collecting effluent from the vermifiltration system after treatment; andchanneling the treated effluent into a wastewater reservoir to reduce greenhouse gas emissions from the surface of the reservoir.The method of claim 1, wherein the vermifiltration system is connected upstream of the wastewater reservoir and receives untreated wastewater prior to storage.The method of claim 1, wherein the vermifiltration system is connected downstream of the wastewater reservoir, draws wastewater from the bottom of the reservoir, and returns treated effluent to the surface of the same reservoir.The method of claim 1, further comprising continuously monitoring gas emissions and system performance using real-time sensors.The method of claim 1, further comprising recovering vermicompost from the vermifiltration system and using it as a soil amendment or fertilizer.A method for generating carbon credits using a vermifiltration system, the method comprising:determining a baseline emission level for a wastewater reservoir receiving organic wastewater;implementing a vermifiltration system in line with the wastewater inflow;reducing methane emissions by promoting aerobic processing of the organic waste;monitoring and verifying the reduction in emissions;issuing carbon credits, each corresponding to a reduction or sequestration of one metric ton of CO₂ equivalent emissions; andengaging in the trade or sale of the carbon credits.The method of claim 6, wherein the vermifiltration system additionally reduces nitrogen concentration in the treated effluent, resulting in reduced nitrous oxide (N₂O) emissions when the effluent is applied to land.The method of claim 6, wherein the carbon credits are tokenized using a blockchain platform and managed via smart contracts.The method of claim 6, wherein the carbon credits are used for insetting within a corporate supply chain.The method of claim 6, wherein the carbon credits are sold to third parties to offset external emissions.A system for reducing greenhouse gas emissions from a wastewater reservoir, comprising:at least one vermifiltration unit comprising a biological filter bed populated by earthworms and aerobic microorganisms;a wastewater reservoir configured to receive treated effluent;fluid conduits operatively connecting the vermifiltration unit and the reservoir, wherein the connection is: (a) upstream of the reservoir, such that untreated wastewater is treated before entering the reservoir; and / or (b) downstream of the reservoir, such that untreated wastewater is drawn from the reservoir, treated in the vermifiltration unit, and returned to the surface of the same or a different reservoir;a distribution mechanism configured to disperse wastewater across the surface of the filter bed; andan effluent collection system configured to transfer treated water from the filter bed to the reservoir.The system of claim 11, further comprising one or more sensors configured to monitor process or emission parameters including pH, temperature, total suspended solids (TSS), oxygen concentration, or methane flux.The system of claim 11, wherein the vermifiltration unit is modular and comprises multiple beds operating in parallel or in sequence to accommodate variations in flow rate or maintenance scheduling.

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