Patent Application
20240344010
Conventional nitrogen and carbon removal from high nitrogen and carbon substances, through processes such as nitrification and heterotrophic denitrification to produce nitrogen gas (N2), results in significant sludge and CO2 production, and requires high aeration energy. In comparison, anaerobic ammonium oxidizing (anammox) bacteria produce only a quarter of the excess sludge, produces less CO2, and reduces the energy required for aeration by 60%. Anammox bacteria have a unique metabolic ability to combine ammonium and nitrite to produce nitrogen gas (N2) in the absence of oxygen. Anammox bacteria are autotrophic, and thus carry out this process without a need for an organic carbon source. Anammox bacterial metabolism of ammonium and nitrite to produce nitrogen gas (N2) provides new possibilities for biological nitrogen removal from wastewater. The application of anammox bacteria to the treatment of high-temperature wastewater has been demonstrated to offer substantial reduction in energy demand for nitrogen removal from wastewater. Although this has led to interest in applying anammox bacteria to mainstream wastewater treatment, a prohibitive challenge is that anammox bacterial activity sharply decreases at the lower temperatures common in the mainstream treatment of wastewater. Similarly, other biological processes like anaerobic digestion of waste, conversion of carbon substrates into biogas, and fermentation of brewer's wort into ethanol by yeast, can benefit from keeping the active organisms at a warmer temperature. Altering the temperature of large volumes of water, such as wastewater, is economically prohibitive due to the significant energy required and its associated costs.
The use of microbes in biofilms attached to gas-permeable membranes is one of the most efficient ways to operate a bioprocess which relies on the feed of a gas such as oxygen, or methane, or carbon dioxide as it can meter the gas delivery very precisely and virtually eliminate waste. The addition of growth surface temperature control to this type of bioreactor generally offers further improved economy and efficiency for many other types of bioprocesses besides the treatment of wastewater streams.
A need therefore exists for controlling the temperature of organism(s) performing the biological process, without the high energy cost of controlling the temperature of large volumes of water.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
In one aspect, a temperature controlled biological growth surface, including a biomass growth surface configured to support a biomass; and a temperature source in thermal communication with the biomass growth surface is disclosed.
In another aspect, a method for removing one or more of nitrogen, carbon, or phosphate from a medium, including contacting a temperature controlled biological growth surface with the medium, wherein the biological growth surface comprises an organism configured to remove the one or more of nitrogen, carbon, or phosphate from the medium when within a temperature range, heating the temperature controlled biological growth surface to within the temperature range in order to allow the organism to remove the one or more of nitrogen, carbon, or phosphate from the medium, or cooling the temperature controlled biological growth surface to within the temperature range in order to allow the organism to remove the one or more of nitrogen, carbon, or phosphate from the medium is disclosed.
In yet another aspect, a method for converting one or more of nitrogen, carbon, or phosphate from a medium, including contacting a temperature controlled biological growth surface with the medium, wherein the biological growth surface comprises an organism configured to remove the one or more of nitrogen, carbon, or phosphate from the medium when within a temperature range, heating the temperature controlled biological growth surface to within the temperature range in order to allow the organism to convert the one or more of nitrogen, carbon, or phosphate from the medium, or cooling the temperature controlled biological growth surface to within the temperature range in order to allow the organism to convert the one or more of nitrogen, carbon, or phosphate from the medium is disclosed.
The foregoing aspects and many of the attendant advantages of this disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the disclosure.
The present disclosure provides a device which selectively heats or cools biological organisms in contact with nitrogen, carbon and or phosphate-containing substances, and methods for use of the device, to metabolize nitrogen, carbon and or phosphate from the substances, reducing the undesirable by-products and prohibitive costs associated with current nitrogen and carbon-removal or harvesting treatment methods as well as fermentation technology.
The device comprises a heated or cooled biological growth surface, which selectively heats or cools a biological organism or consortium of organisms', thus eliminating the high energy requirement and associated costs of heating or cooling large volumes of substances. Use of bacteria such as anaerobic ammonium oxidizing (anammox) bacteria to effect nitrogen removal from substances significantly reduces sludge by-product, CO2 production, and aeration energy required by conventional nitrification and heterotrophic denitrification processes.
In addition to anammox bacteria, other biomass that prefer warmer temperatures, such as anaerobic bacteria, nitrifying bacteria, methanogen or methanotroph, denitrifying organisms, sulfate reducers, sulfate oxidizers, carbon- or nitrogen-processing heterotrophic or phototrophic prokaryotes, carbon- or nitrogen-processing heterotrophic or phototrophic eukaryotes, fungal strains such as yeast, and combinations thereof, can be used. Some of these organisms can be found in anaerobic digesters or fermenters utilized in the food and biochemical industry. Other disclosed organisms can be found in environments in which carbon feed stock is used as fuel, such as in petrochemical, pharmaceutical, and food production applications.
Use of the device described herein to selectively heat or cool biological organisms, such as biomass, bacteria, biofilm, yeast, and other biological organisms, then contacting the heated or cooled biological organisms with nitrogen, carbon, and/or phosphate-containing substances effects nitrogen, carbon, and phosphate removal or harvesting from the substance. Embodiments in the present disclosure are not limited to aqueous applications, but can be applied to other liquids, as well as solid or gas mediums. The nitrogen-, carbon-, and/or phosphate-containing substances of the disclosure can be mediums such as liquid, solid, and/or gas. A liquid medium comprising a nitrogen-, carbon-, and/or phosphate-containing substance can comprise wastewater, contaminated water, water comprising a nitrogen-, carbon-, and/or phosphate-containing substance, a carbon feed stock used for fuel, a carbon feed stock for pharmaceutical production, and/or a carbon feed stock for food production. A gas medium can comprise ambient air comprising a nitrogen-, carbon-, and/or phosphate-containing substance, a gas mixture comprising a nitrogen-, carbon-, and/or phosphate-containing substance, or a waste gas. A solid medium comprising a nitrogen-, carbon-, and/or phosphate-containing substance could comprise a soil sample or contaminated rock.
The primary means for heating or cooling biological organisms utilized by the device and the methods described herein comprises electric resistance heating; convection heating and cooling by a heated or cooled gas or liquid; and/or radiation heating. Such heating or cooling can heat or cool the bacteria, biomass, biofilm, yeast, or other biological organisms (hereinafter referred to as biomass) directly; through a matrix comprising the biomass, such as a hydrogel or other porous matrix configured to permit diffusion of growth substrates and metabolic products in and out of the matrix; or a biomass growth surface upon which the biological organisms, biomass, biofilm, or matrix comprising the biomass is deposited or grown.
Certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the disclosure which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable sub-combination. Accordingly, both devices and methods of using the devices are disclosed.
In some embodiments, the disclosure provides a biomass growth surface heated or cooled with resistive heat, gas convection, liquid convection, radiation heat, and combinations thereof. In certain embodiments, the heated or cooled biological growth surface comprises a biofilm on the biomass growth surface. In other embodiments, the heated or cooled biological growth surface or biomass growth surface comprises a hydrogel in contact with a biomass. Embodiments comprising a hydrogel can comprise a hydrogel layer; a plurality of beads comprising a hydrogel matrix; or other hydrogel-containing configuration or composition. Hydrogel beads can comprise hydrogel that is smooth, regular, irregular, rough, porous. In certain embodiments, hydrogel beads comprise biomass, particles, pigment, other additives, or combinations thereof.
In other embodiments, the heated or cooled biological growth surface or biomass growth surface comprises a porous matrix in contact with a biomass. Such porous matrix is configured to permit diffusion of growth substrates and metabolic products in and out of the matrix. Embodiments comprising a porous matrix can comprise a porous matrix layer; a plurality of beads comprising a porous matrix; or other porous matrix-containing configuration or composition. Porous matrix beads can be smooth, regular, irregular, rough, porous. In certain embodiments, porous matrix beads comprise biomass, particles, pigment, other additives, or combinations thereof.
In the foregoing and the following embodiments disclosed herein, biomass can comprise a biological organism, or a consortium of organisms wherein more than one type of organism is utilized. In such embodiments, the biological organism or consortium of organisms can comprise bacteria, biomass, biofilm, biomass in contact with a matrix such as a hydrogel or other porous matrix, anaerobic ammonium oxidizing (anammox) bacteria, nitrifying bacteria, methanogen or methanotroph, denitrifying organisms, sulfate reducers, sulfate oxidizers, carbon- or nitrogen-processing heterotrophic or phototrophic prokaryotes, carbon- or nitrogen-processing heterotrophic or phototrophic eukaryotes, fungal strains such as yeast, and combinations thereof.
In some embodiments, the biological growth surface comprises a membrane, a carbon fiber filament, a carbon fiber ribbon, a metal plate, a pigmented membrane, or a combination thereof.
In some embodiment, a biomass growth surface heated with electric resistive heat or resistance-based heating elements is disclosed. In certain embodiments, a heating wire can be located inside a hollow fiber membrane, or it can be located on the surface of a membrane. A low voltage (e.g., 24V, powering parallel circuits, each 5 ft segments of 36-gauge nichrome) can then be applied to prevent the system from overheating the biomass. The heating wire can comprise nichrome. The electric circuit or nichrome circuit can be controlled by a PID (proportional-integral-derivative) temperature controller which controls the temperature of the biomass growth surface, and a temperature sensor (e.g., infrared sensor, thermocouple, or RTD (“Resistance Temperature Detector”) which detects the temperature of the biomass growth surface. For example, the setpoint temperature range for a biological organism such as anammox could be between about 20° C. to about 60° C., from about 20° C. to about 50° C., from about 25° C. to about 45° C., or from about 30° C. to about 40° C. Such a temperature range permits a biological organism such as anammox, aerobic thermophilic organisms, and/or anaerobic thermophilic organisms to achieve their maximal growth rate, and consequently achieve high nitrogen-, carbon-, and/or phosphate removal or harvesting efficiencies.
In some embodiments, the temperature is controlled through a PID temperature controller 120. The PID temperature controller may be coupled, either physically or communicatively, to a temperature probe 115 and a temperature source 125. As illustrated in
In operation, as shown in
In some embodiments, the resistance heating element is integrated into a flat, cylindrical, or other shaped membrane (e.g., woven in), for example, during the membrane manufacturing process. In a further embodiment, carbon fibers, or another heating element, could be used to strengthen the membrane while concurrently providing heat when a voltage is applied to the carbon fiber or other heating element.
In some embodiments, carbon fiber 225B, or another temperature source 225, is integrated into the biological growth surface 210. In some embodiments, the biological growth surface 210 includes a hydrogel or other porous matrix in contact with the biomass. In a further embodiment, an underlying surface (e.g., a membrane) may add additional support to the biological growth surface 210, or the hydrogel or other porous matrix may be engineered and reinforced for adequate strength to sustain biomass without external structural support.
In other embodiments, the disclosure provides a biomass growth surface heated or cooled with gas convection or liquid convection. In certain embodiments, the gas and/or liquid are heated. In certain embodiments, the gas and/or liquid are cooled. In some embodiments, the gas comprises heated air or another heated composition of gas. In some embodiments, the gas comprises cooled air or another cooled composition of gas. In some embodiments, the liquid comprises heated water, heated wastewater, a heated glycol mixture, or combinations thereof. In certain embodiments, the liquid comprises cooled water, cooled wastewater, a cooled glycol mixture, or combinations thereof.
In some embodiments, heated gas or heated liquid supplies heat to the non-growth side of a biomass growth surface, to transfer heat to the biomass. For example, heated gas such as air could flow inside a hollow fiber membrane with biomass growing or deposited on the outside of the membrane, wherein the heated gas contacts the biomass growth surface. Such heated gas could comprise waste heat air and/or solar heated air. In certain embodiments, heated liquid such as waste heat liquid (e.g., water from a cooling operation, and/or glycol from a cooling operation) or solar heated liquid could be used to heat the biomass growth surface by passing the liquid over the surface opposite of where the biomass is grown, allowing the surface to conduct heat to the biomass from the liquid.
In some embodiments the temperature source 125 is a cooling source and is selected from a cold reservoir of air or water, liquid convection cooling, evaporative cooling, radiation cooling, and combinations thereof. In some embodiments, cooled gas or cooled liquid reduces the heat to the non-growth side of a biomass growth surface, to transfer heat away from the biomass. For example, cooled air, such as gas, may flow inside a hollow fiber membrane with the biomass is growing or deposited on the outside of the membrane, where the cooled gas contacts the biomass growth surface. Such cooled gas could comprise air cooled from a cold outdoor environment, cooled with a heat pump, cooled with a geothermal source, or cooled through heat exchange with a body of water or wastewater source. In some embodiments, liquid cooled from a cold outdoor environment, cooled with a heat pump, cooled with a geothermal source, or originating from a colder water body or wastewater source is configured to conduct heat away from the biomass growth surface by passing the liquid over the surface opposite of where the biomass is grown, allowing the surface to conduct heat away from the biomass and to the liquid.
The heat transfer in the foregoing embodiments can be controlled by monitoring the temperature of the biomass growth surface or biomass itself through infrared, thermocouple, or RTD temperature probes, and modifying the heat gain or heat loss by adjusting the flow rate of the heated or cooled gas or liquid, or adjusting the temperature of the gas or liquid, to maintain a specific biomass temperature. For example, the setpoint temperature range for a biological organism such as anammox could be between about 20° C. to about 60° C., from about 20° C. to about 50° C., from about 25° C. to about 45° C., or from about 30° C. to about 40° C. Such a temperature range permits a biological organism such as anammox, aerobic thermophilic organisms, and/or anaerobic thermophilic organisms to achieve their maximal growth rate, and consequently achieve high nitrogen-, carbon-, and/or phosphate removal or harvesting efficiencies.
In some embodiments, a method for removing one or more of nitrogen, carbon, or phosphate from a medium, including contacting a temperature controlled biological growth surface 110 with the medium, wherein the biological growth surface 110 comprises an organism configured to remove the one or more of nitrogen, carbon, or phosphate from the medium when within a temperature range, and heating the temperature controlled biological growth surface 110 to within the temperature range in order to allow the organism to remove the one or more of nitrogen, carbon, or phosphate from the medium, or cooling the temperature controlled biological growth surface 110 to within the temperature range in order to allow the organism to remove the one or more of nitrogen, carbon, or phosphate from the medium is disclosed.
In some embodiments, a method for converting one or more of nitrogen, carbon, or phosphate from a medium, including contacting a temperature controlled biological growth surface 100 with the medium, wherein the biological growth surface comprises an organism configured to remove the one or more of nitrogen, carbon, or phosphate from the medium when within a temperature range, and heating the temperature controlled biological growth surface 110 to within the temperature range in order to allow the organism to convert the one or more of nitrogen, carbon, or phosphate from the medium, or cooling the temperature controlled biological growth surface 110 to within the temperature range in order to allow the organism to convert the one or more of nitrogen, carbon, or phosphate from the medium is disclosed. In some embodiments, the medium is a liquid. In some embodiments, the liquid comprises wastewater, contaminated water, water comprising the one or more of nitrogen, carbon, or phosphate, a carbon feed stock for fuel, a carbon feed stock for pharmaceutical production, a carbon feed stock for biochemical production, a carbon feed stock for monomer or polymer production, or a carbon feed stock for food production.
In other foregoing and following embodiments disclosed herein, the disclosure provides heating by radiation heat. In certain embodiments, radiation heat is in communication with the biomass directly, with the biomass growth surface, and/or a biomass growth surface such as a hydrogel or other porous matrix, which effects heating of the biomass, the biomass growth surface, and/or the hydrogel or other porous matrix. In certain embodiments, radiation heat comprises radiation in the visible range and/or infrared range. In other embodiments, radiation heat comprises a spectrum of radiation broader than the visible and infrared range. In further embodiments, radiation heat comprises a broad spectrum of radiation combined with a radiation filter which eliminates or reduces certain wavelengths of radiation from contacting the bacterial growth surface, such as certain wavelengths of UV radiation. Radiation heat comprises radiation emitted from a light and/or radiation emitted from a source such as the sun.
Heating the biological growth surface will take advantage of the properties of water. Water absorbs radiation heavily above 3000 nm, but the absorption of radiation by water quickly reduces at wavelengths below 3000 nm and has a minimum near 500 nm. In certain embodiments, radiation with a wavelength from around 200 nm to around 2500 nm is used to selectively heat suspended, biofilm-based, and/or hydrogel or other porous matrix in contact with a biomass, with minimal loss of energy to the surrounding water. The radiation can be provided electronically through lights at a specific wavelength or range of wavelengths, by solar radiation, or by filtered solar radiation. Filtered solar radiation permits specific wavelengths of light to penetrate the biological growth surface while concurrently preventing specific wavelengths which are harmful to biomass (e.g., a UV removing water filter) from contacting the biomass, biomass growth surface, and/or biomass growth surface such as a hydrogel or other porous matrix.
Absorption of radiation by the biomass can be enhanced by particle, pigment, or other additives added in proximity to organisms which have high absorption corresponding to the wavelength of radiation in which the device is exposed. Particles, pigments, or other additives comprise radiation-absorbing ability. For example, in embodiments in which a hydrogel or other porous matrix is in contact with a biomass, the embodiments can further comprise carbon black powder, wherein the carbon black powder can absorb radiation with a wavelength between about 200 nm to about 2,500 nm. Carbon black powder provides the further advantage that it is relatively inexpensive, chemically inert, and non-toxic to most organisms. In other embodiments, biomass which naturally absorb certain wavelengths of radiation can be paired with specific radiation at the wavelengths they absorb.
In further embodiments, a device can comprise more than one type of biomass, wherein each type of biomass has a different optimal temperature. In such embodiments, the concentration of particles or pigments added can be adjusted so that each type of biomass will experience different temperatures in near proximity to it or near each other. For example, nitrifying bacteria could be immobilized in hydrogel beads with no or low concentrations of radiation-absorbing particles, pigments, or other additives, while anammox bacteria could be immobilized in hydrogel beads with a high concentration of particles, pigments, or other additives. If both sets of hydrogel beads are placed in the same device and exposed to radiation (e.g., 500 nm green light) then nitrifiers will experience moderate temperatures while anammox bacteria will experience relatively moderate to high temperatures. This permits the device comprising anammox to operate with a wider range of biomass organisms and enables each type of biomass to exist at their maximum specific growth rate. In this example, anammox can receive its electron acceptor nitrite from the nitrifying organisms to then form dinitrogen gas leading to oxygen efficient nitrogen removal.
In certain embodiments, the device temperature is controlled by a control unit which measures the temperature of the biomass through an RTD, thermocouple, or infrared sensor, and controls the flux of radiation into the device based on the detected temperature of the biomass. For example, the setpoint temperature range for a biological organism such as anammox could be between about 20° C. to about 60° C., from about 20° C. to about 50° C., from about 25° C. to about 45° C., or from about 30° C. to about 40° C. Such a temperature range permits the biological organism such as anammox, methanogens, or yeast to achieve their maximal growth rate, and consequently achieve high nitrogen-, carbon-, and/or phosphate removal or harvesting efficiencies. The controller will reduce the flux of radiation from the radiation source (e.g., lights, LEDs, and/or solar) once the temperature of the biological organism such as anammox becomes higher than the setpoint and will increase the flux of radiation if the temperature falls lower than the setpoint. Otherwise, the flux of radiation will be kept at a proximally fixed level. The temperature will be sensed by, for example, an infrared sensor with a programmable logic controller that can distinguish the temperature signal of a liquid medium, such as water, from the biomass or hydrogel beads in contact with biomass. Additionally, temperature of the biomass can be controlled by changing the flow rate of nutrient fluid (gas or liquid) across the biomass. The concept of direct heating of biomass using radiation is shown in
In other embodiments, the biomass growth surface is heated by its communication with radiation. This can be achieved with materials that absorb broad spectrum radiation, which shields the biomass from much of the direct radiation, while conducting heat to the biomass. The temperature of the biomass can be controlled by a radiation filter, which blocks or reflects certain wavelengths of radiation from reaching the biomass growth surface when the temperature gets too high. In such embodiments, the temperature can be controlled by adjusting the flowrate of nutrient flow across the biomass (e.g., flowrate of a wastewater stream), which in effect adjusts the rate of cooling. This technique is advantageous because the growth rate of many organisms is tied to temperature, and therefore the rate of nutrient supplied to organisms can be adjusted to meet higher or lower growth rates. Both nutrient supply and increased cooling can be achieved by increasing the flowrate of a nutrient rich liquid or gas across the biomass (e.g., increased rate of wastewater flow across the biomass).
Two Anammox based reactors were tested at the pilot scale: a reactor system containing hydrogels embedded with Anammox biomass and carbon black (reactor 1: Hydrogel-on the left side of
Schematic design of the reactors is shown in
According to the schematic design of the two reactors, major materials and equipment was purchased or prepared, and are summarized in Table 1.
A site close to the primary clarifier at Everett wastewater treatment plant (WWTP) was selected for the pilot operation with consideration of access to electricity and reactor feeds (the effluent from the primary clarifier). A trailer located at the operation site was provided by the Everett Utility as the shelter for reactors. Connection of electricity and primary effluent to the trailer were set up by the staff of Everett staff. To improve the space utilization in the trailer, Unistrut shelves were made by the UW team members.
Before preparing hydrogel beads for the hydrogel reactor, a preliminary experiment was performed to investigate possible inhibition effect of carbon black, which is the radiation absorbent material, on the biomass activity and results showed no inhibition of radiation absorbent materials on biomass. Hydrogel beads were prepared by immobilizing Comammox and Anammox into 10% PVA-1% SA hydrogel beads and crosslinking with 2% CaCl2-3% boric acid followed by post-cure in 0.5 M Na2SO4. 0.125% homogenized carbon black powder were mixed into the hydrogel beads to make beads optically black to enhance their light absorbance capacity over a broad range of wavelengths.
A nichrome resistance heating module by the combination of nichrome wire and thermally conductive tape was constructed for the membrane reactor. A low voltage power box, which converts 120 V electricity to 5-24 V, was used for power supply for the heating module. The heating module was placed across and closely attached to the membrane fiber strips to ensure the direct heating of biomass on the membrane fiber strips. The heating module was tested before operation of reactors and showed sufficient capacity to heat the membrane to designed temperature.
For the heating module of the hydrogel reactor, a halogen lamp emitting light at wide spectrum was used as radiation source for heating in first attempt of the operation. This unsuitable radiation source promoted the growth of algae in the reactor and can be a reason of the failure of the first attempt of operation. An updated heating module was prepared with using LED lights which emitted light at a focused wavelength. This proposed new LED light source emitted light at a specific and human invisible wavelength of 900 nm which cannot be utilized by algae or be efficiently absorbed by water. A comparison of heating with water and water containing carbon black (light absorbent material used for hydrogel beads in the hydrogel reactor) demonstrated low absorbance by water and enhanced absorbance by addition of carbon black.
An Arduino was used for the microcontroller shown in
Planed sampling and sample analysis for the two reactors are shown in Table 2. Routine sampling, sample analysis for physico-chemical parameters were performed by staff in the Everett WWTP. Additional samples of daily influent and effluent were stored at −20° C. for potential physico-chemical parameters and molecular analysis by UW team members. Reactor operational conditions, including flow, leakage of tubing, pressure of air or nitrogen tank, and temperature controls were monitored and maintained by the Everett plant staff and UW team members.
1Sequencing conducted after all samples are collected
The hydrogel reactor was setup at the Everett WWTP for pilot operation.
The hydrogel reactor was transferred to Everett WWTP for onsite pilot operation. A LED light source emitting light at a specific and human invisible wavelength of 900 nm was used as it cannot be utilized by algae, but that can still heat the biomass (but not the water).
This application claims the benefit of U.S. Provisional Application No. 63/233,071 filed Aug. 13, 2021, the entire disclosure of which is hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/074816 | 8/11/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63233071 | Aug 2021 | US |
