Volume reduction solids processing system

Abstract

A system and method for reduced solids processing of fecal waste is described. The system includes a pasteurizer (102) configured to receive a slurry batch and heat the slurry batch at an elevated temperature for a period of time to produce a pathogen-free slurry. The system also includes a mechanical dewatering press (14) configured to compress the pathogen-free slurry to separate a liquid phase from the reduced solids waste. The reduced solids waste is formed into a fecal cake. The system also includes a drying tunnel (106) including a means for removing the liquid phase and a conveyor housed within an air duct system. The air duct system is configured to force air over the fecal cake.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Provisional Application No. 63 / 222,740, entitled "Volume - Reduction Solids Treatment System", filed on July 16, 2021, the entire content of which is incorporated herein by reference.

Background Art

[0002] An estimated 4.5 billion people worldwide do not have access to a safe and affordable sanitation system. High levels of child mortality and disease are associated with fecal - oral contamination where feces containing pathogens contaminate food and drinking water. Where conventional sanitary sewer systems are unavailable or impractical, sanitation systems that do not use sewers are needed.

Summary of the Invention

[0003] The present specification discloses a solids excrement treatment system comprising a pasteurizer, a mechanical dewatering press, an outlet for removing the treated liquid phase, and a drying tunnel. The pasteurizer is configured to receive a slurry batch and heat the slurry batch at a high temperature for a certain period to produce a pathogen - free slurry, and the slurry batch contains at least feces. The mechanical dewatering press is configured to compress the pathogen - free slurry to separate the liquid phase from the volume - reduced solid excrement formed in the fecal cake. The drying tunnel comprises a conveyor housed within an air duct system, and the air duct system is configured to propel forced air over the fecal cake within the drying tunnel. Also disclosed is a method of treating human excrement using the disclosed solids excrement treatment system.

[0004] Other systems, methods, features, and advantages of this disclosure will become apparent to those skilled in the art upon consideration of the following drawings and detailed description. All such additional systems, methods, features, and advantages are included in this description, are within the scope of this disclosure, and are intended to be protected by the appended claims. Furthermore, any preferred features and modifications of all embodiments described are available in all aspects of the disclosure taught in this specification. In addition, the individual features of the dependent claims, as well as any preferred features and modifications of all embodiments described, can be combined with and are interchangeable with one another. [Brief explanation of the drawing]

[0005] Many aspects of this disclosure can be better understood by referring to the following drawings. The elements in the drawings are not necessarily drawn to a consistent scale; instead, the focus is on clearly illustrating the principles of this disclosure. In the drawings, the same reference numbers indicate corresponding parts across several drawings.

[0006] [Figure 1] Figure 1 shows an exemplary diagram of a volume reduction solids processing system according to various embodiments described in this specification.

[0007] [Figure 2A] Figures 2A and 2B show exemplary rear and front views of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification. [Figure 2B] Figures 2A and 2B show exemplary rear and front views of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification.

[0008] [Figure 3A] Figures 3A and 3B show exemplary pasteurizers of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification. [Figure 3B]Figures 3A and 3B show exemplary pasteurizers of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification.

[0009] [Figure 4A] Figures 4A to 4D show exemplary filter presses of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification. [Figure 4B] Figures 4A to 4D show exemplary filter presses of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification. [Figure 4C] Figures 4A to 4D show exemplary filter presses of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification. [Figure 4D] Figures 4A to 4D show exemplary filter presses of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification.

[0010] [Figure 5] Figure 5 shows an example of a drying tunnel for the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification.

[0011] [Figure 6A] Figures 6A and 6B show exemplary concentrators of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification. [Figure 6B] Figures 6A and 6B show exemplary concentrators of the volume reduction solids processing system of Figure 1 according to various embodiments described in this specification.

[0012] [Figure 7] Figure 7 shows exemplary methods for reducing the volume of solids according to various embodiments described in this specification.

[0013] [Figure 8]FIG. 8 shows an exemplary schematic view of a volume-reducing solid waste treatment system used as a module within a non-sewered single unit toilet system according to various embodiments described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Sanitation systems are needed in regions of the world where outdoor excretion and lack of improved sanitation are common and can lead to disease. Conventional sewage and wastewater treatment plants that receive excrement from sewers can be costly to introduce and operate. Collective toilet technologies have been developed to treat excrement on a large scale. However, there is a need for technology that provides access to safe and affordable sanitation systems that can be introduced even in households without sewer connections. Overall, as water shortages worsen worldwide, sanitation systems that reduce dependence on large amounts of water in the long-distance transport of excrement are becoming increasingly important not only in developing countries but also around the world.

[0015] To address these drawbacks, systems for use in stand-alone non-sewered toilet systems are discussed here. The system can be configured to prepare human excrement for safe disposal by inactivating pathogens. The system can also recover valuable resources such as clean water. The system can be configured to operate without connection to an input water or output sewer. Some system examples can also be battery-based or powered by off-grid renewable energy. The system can be optimized to achieve low-cost manufacturing and low operating costs. This system can promote sustainable sanitation services that are operated not only in developed and developing countries but also in poor urban environments.

[0016] The ISO 30500 standard provides technical standards for sanitation systems that do not use sewers, designed to address basic sanitation needs and promote economic, social, and environmental sustainability through strategies that minimize water and energy consumption and convert human excreta into safe outputs. These sanitation systems operate without connection to sewers or drainage networks and aim to meet health and environmental safety and regulatory parameters. In some instances, the systems described herein may be configured to provide a treatment output that meets or exceeds the ISO 30500 standard.

[0017] For example, the flow of human excreta can include urine, feces, diarrhea, etc. Sanitary adjuncts can include toilet paper, feminine hygiene excreta, diapers, and other paper products, etc. In some toilet systems, some of the sanitary adjuncts, including non-organic products such as diapers, can be received and processed separately from the flow of human excreta. In some instances, the excreta flow includes human feces and urine, menstrual blood, bile, flush water, anal cleansing water, toilet paper, other body fluids and / or solids. Further, the excreta flow can include water such as flush water, rinse water, washing water, fresh water, consumption water, drinking water, usable water, etc.

[0018] For example, a standalone non-sewer toilet system may include a liquid treatment system and a solid treatment system, each operating as a separate system or interconnected for the treatment of human waste. A standalone non-sewer toilet system may also include at least one separation system. In some examples, the contents of the human waste stream can be separated or treated individually. Separating the stream allows for more efficient treatment than a mixed human waste stream by dividing the raw materials into primarily feces, urine, and wastewater streams. Since 100% separation is not practical, some degree of cross-contamination between streams is acceptable in subsequent downstream treatment approaches. As described in this specification, a fecal stream, which mainly consists of feces, is also called a “brown stream.” A brown stream is mostly feces, but may also contain other liquid and solid waste. For example, a brown stream may contain feces, toilet paper, some urine, and some water. As described in this specification, the “green flow” may consist mostly of water, some urine, and some toilet paper, and typically does not contain feces. The green flow is mostly liquid, with some solids. As described in this specification, the urine flow, which mainly consists of urine, is also called the “yellow flow.” For example, the yellow flow may contain urine and some water. As described in this specification, the wastewater flow is also called the “blue flow.” For example, the blue flow may mainly consist of wastewater in the form of flush water, urinary lavage water, or excess water poured into the toilet. In some cases, the blue flow may also contain some urine. Given the variability of small amounts of fecal deposits (mostly recognized as diarrhea), large amounts of urine deposits, and excess amounts of flush and urinary lavage water, and considering the constraints of future water shortages, flow separation can result in a lower-cost and more robust treatment process.

[0019] In the context described above, various examples of systems and methods for volume reduction and solids treatment of fecal excretion logistics are described in this specification. A volume reduction and solids treatment system is a solids treatment system that can operate independently or be configured for use in a standalone non-sewerage toilet system. Fecal excretion logistics may include not only feces contained in the excretion logistics collected in a toilet system, but also urine, water, and other substances associated with sanitation facilities. A volume reduction and solids treatment system can be integrated as a solids treatment module in a standalone non-sewerage sanitation system. For example, a volume reduction and solids treatment module can be integrated for use in a single-unit toilet system configured to reduce adult excrement to water, carbon dioxide, and mineral ash. In some examples, a volume reduction and solids treatment system can be configured to provide a treatment output that meets or exceeds the ISO 30500 standard.

[0020] Volume reduction solids processing systems can be used to process fecal and brown flows of human waste. By separating the brown flow before introducing it into the volume reduction solids processing system, the system can operate to process the solids it contains. Furthermore, by removing excess liquid from the brown flow and homogenizing its contents, a brown flow slurry can be obtained. For example, the brown flow slurry can be obtained in an external system or module of the volume reduction solids processing system. In one example, the brown flow may be received in a collection tank and processed into a slurry. In one example, the collection tank may be a flow mixing container that receives multiple waste flows.

[0021] Methods and systems for volume reduction and solids treatment may include pasteurization and volume reduction processes for treating human excrement in a toilet environment to produce a pathogen-free fecal cake suitable for either combustion and reduction to ash or other disposal. In some examples, the volume reduction and solids treatment system can operate as part of a single-unit toilet system. Fecal slurry is sent to a pasteurization heater and kept at a high temperature until pathogens are killed. The treated excrement slurry can be transferred at the high temperature to a mechanical dewatering filter press. The treated slurry is compressed, and the volume reduction and solids excrement is discharged from the filter press as a fecal cake onto a conveyor. The change in volume from the input slurry to the fecal cake output can be evaluated as a change in moisture content. For example, the moisture content of the input slurry may be 96 to 99%, and the moisture content of the output press cake may be 28 to 84%. This reduction in moisture content corresponds to a reduction of at least 80% in volume. The reduction in volume may exceed 95%.

[0022] In one example, the removed liquid phase can be sent outside the system for processing in another liquid treatment system. In one example, the conveyor can transport the fecal cake to the disposal container over a period of 8 to 10 hours. In one example, the conveyor can be housed in a drying tunnel. The drying tunnel is a sealed air duct system that allows forced air to be blown over the fecal cake during transport, enabling evaporation and drying of the fecal cake. The final cake has a moisture content of 4 to 10% and is placed in a removable container for subsequent disposal. In one example, the fecal cake can be converted to ash in an external combustion system.

[0023] The following description provides a general description of volume reduction solids treatment systems and their components, including a description of the operation of the treatment system. Non-limiting examples of volume reduction solids treatment systems are described. In some examples, this configuration may include optional connections for integrating the volume reduction solids treatment system with other systems, including standalone non-sewerage sanitation systems. For example, a volume reduction solids treatment system can be integrated with a urine and wastewater treatment system.

[0024] As shown in Figure 1, the volume reduction solids processing system 100 may include a pasteurizer 102, a filter press 104, and a drying tunnel 106. The volume reduction solids processing system 100 is configured to receive fecal slurry and produce a pathogen-free fecal cake. The volume reduction solids processing system 100 may also include a controller 115 for operating valves, pumps, motors, actuators, switches, and sensors (not shown). Fecal slurry is slurry containing feces, but may also contain other excrement. As described in this specification, fecal slurry may be a brown stream slurry that may contain feces, urine, toilet paper, and / or water. Fecal slurry may be received from a separate system equipped with a homogenizer that breaks down solid excrement into uniform particle sizes. For example, the homogenizer may be a macerator or grinder. In some examples, fecal slurry may be received from a system that separates liquids and solids from a human excrement logistics of mixed contents. In some cases, fecal slurry can be received from a buffer tank that holds solid waste.

[0025] A batch of fecal slurry can be received into the pasteurizer 102. In some examples, the batch of fecal slurry can be received directly from a separation and homogenization system, or from another system including a homogenizer that forms fecal slurry from solids separated from human excrement. The batch of fecal slurry can be heated at a high temperature in the pasteurizer 102 for a sufficient time to kill pathogens. For example, the high temperature can be at least 85°C. For example, a batch of fecal slurry can be processed in the pasteurizer 102 at about 95°C for about 10 minutes. The processed output from the pasteurizer 102 may be pathogen-free or pathogen-reduced fecal slurry. In one example, the pasteurizer 102 can process 6 L of fecal slurry per day in 100 mL batches to achieve pathogen reduction. In some examples, the processed slurry output of the pasteurizer conforms to ISO 30500.

[0026] The processed slurry can be sent from the pasteurizer 102 to the filter press 104. The filter press 104 may be a mechanical dewatering filter press comprising a solids chamber 114, a piston 116, and a filter gate 118. The filter press 104 can receive the processed slurry, also referred to in this specification as pasteurized brown stream, into the solids chamber 114. The filter press 104 is configured to actuate the piston 116 to reduce the volume of the solids chamber 114 and compress the processed slurry against the filter gate 118 to form a fecal cake. The filter gate 118 comprises a filter screen 120. For example, the filter screen 120 may be a nylon net of 41 to 160 μm, a stainless steel mesh of 140 to 508 μm, or other perforated plate. For example, the filter screen 120 may be a 508 μm stainless steel mesh filter. When the processed slurry is compressed, liquid can be extracted from the slurry and discharged through the filter gate 118. The extracted liquid or filtrate can be collected. In some examples, the filtrate may be sent to a separation and homogenization system to separate the particles.

[0027] The filter gate 118 can move to shear the fecal cake from the filter, open the chamber, and discharge the fecal cake. In one example, a squeegee 122 may be driven by a motor 124 and a belt drive 125 to send the wet fecal cake to a drying tunnel 106. The drying tunnel 106 may comprise a drying belt or conveyor 130. The drying tunnel 106 can reduce the moisture content of the filter cake through the sticky phase to a level that allows for discharge from the belt and solids container. In one example, the drying tunnel 106 may comprise a conveyor 130 housed within a sealed air duct system 134 configured to push forced air over the fecal cake to provide evaporative drying of the fecal cake during transport. For example, the conveyor 130 may transport the fecal cake to a waste container 132 over a period of 2 to 3 hours.

[0028] In some examples, the volume reduction solids treatment system 100 may also interface with a concentrator 112 or a concentration tank of a liquid treatment system. The concentrator may be a pasteurization and evaporation module. For example, mixed waste can be separated into liquid and solid components before being fed into the volume reduction solids treatment system 100. The liquid treatment system can output waste fluid containing solids that cannot be processed by the liquid treatment system. The waste fluid can be reduced in volume by heating the fluid in the concentrator 112. In one example, pressurized air can be introduced into the concentrator so that humidified air and / or off-gas are released and a concentrate remains. The condensed effluent or concentrated volume can be sent to a drying tunnel 106 to remove residual moisture content. In one example, the drying tunnel 106 can receive the concentrate from the liquid treatment system. For example, the drying tunnel 106 can evaporate more than 4 L / day of concentrate. In some examples, the drying tunnel 106 may further include means for discharging gas.

[0029] Figures 2A and 2B show a rear and front view of the exemplary volume reduction solids processing system 100 of Figure 1. In this space-saving example, fecal slurry is received at the pasteurizer inlet 146 and flows through the piping 140 of the pasteurizer 102 to the pasteurizer outlet 148. The pasteurizer outlet 148 is in fluid communication with the filter press inlet 126. After pasteurization, the processed slurry can be sent to the filter press 104 via the pasteurizer outlet 148. The filter press 104 can be operated to form a fecal cake that is discharged from the filter press outlet 128. The fecal cake is transported through the drying tunnel 106 for a period of time and can be discharged into the waste container 132 via the drying tunnel outlet 150 (Figure 2B).

[0030] As shown in Figure 2B, the drying tunnel 106 may comprise a drying belt 136 housed within a sealed air duct system 134 for forcing air onto the fecal cake (not shown) during transport and evaporating and drying the fecal cake. The drying tunnel 106 has a proximal end 152 and a distal end 154, and the drying belt 136 extends around rollers 138a, 138b positioned at the proximal end 152 and the distal end 154, respectively. The drying belt 136 is configured to transport the fecal cake from where it is sent from the filter press 104 to the proximal end 152 to the distal end 154 where it is discharged into the solid waste container 132. In some examples, the drying belt 136 is arranged at an incline from the proximal end 152 to the distal end 154. In some examples, the drying belt 136 may comprise a mesh to allow airflow. For example, the drying belt 136 may be made of polymer mesh or metal mesh. As shown in this example, the volume reduction solids processing system 100 may also include a solids waste container 132 for receiving dry or nearly dry fecal cake. The fecal cake can be sent by the user in the waste container 132 to a combustor or appropriate system to be reduced to ash or disposed of by other means.

[0031] Figures 3A and 3B show the exemplary pasteurizer 102 of Figure 2A in more detail. The pasteurizer 102 may include piping 140 and one or more heaters 142a to d (individually “heater 142”, collectively “heater 142”). For example, fecal slurry is received into piping 140 at the pasteurizer inlet 146, heated by heaters 142a to d at a high temperature for a time sufficient to kill pathogens, and the treated slurry is output through the pasteurizer outlet 148. In this example, heater 142 may be a heater wrap configured to surround the pipe, but other types and heater configurations may be implemented depending on the type and configuration. Valves 156 at the pasteurizer inlet 146 and 158 at the pasteurizer outlet 148 may be configured to control the flow of slurry through the respective pasteurizer inlet 146 or pasteurizer outlet 148. The pasteurizer 102 may also include a flush water inlet 160 and a valve 162 configured to receive the inflow of water for flushing the piping 140. For example, valves 156, 158, and 162 may be two-way valves. The pasteurizer 102 may also be equipped with a pressure relief valve 164 and a burst pressure outlet 168 to protect the pasteurizer 102 during overpressure events.

[0032] For example, a batch of fecal slurry can be processed in a pasteurizer 102 at approximately 95°C for approximately 10 minutes. In one example, the heaters 142 may be independently controlled to allow for more energy-efficient heating. For example, multiple heaters 142 with independent temperature control can be used to form multiple zones along the length of the piping. As an example, as shown in Figure 3, one or more heaters 142a to 142d may be multiple sections of a heater wrap wrapped around the piping 140, forming multiple heating zones independently controlled via multiple control thermocouple ports 144a to 144d (individually “thermocouple port 144”, collectively “thermocouple port 144”). In this example, thermocouple ports 144 for temperature control are shown, but implementations may also rely on devices of other types and configurations for measuring and controlling the temperature of the heaters 142. In one example, the pasteurizer may be configured so that the output meets the pathogen reduction requirements of ISO 30500. For example, the number of E. coli bacteria in the final solids may be less than 100 per gram. In some cases, the E. coli count may range from 19 to 2395 per gram of material. In some cases, the E. coli count may be below the detection limit.

[0033] Figures 4A to 4D show the exemplary filter press 104 of Figure 2A in more detail. The processed slurry can be received into the solids chamber 114 of the filter press 104. The solids chamber 114 may be cylindrical in shape and configured to receive a piston 116. The piston 116 can be actuated to reduce the volume of the solids chamber 114 and apply pressure to the processed slurry against the filter gate 118 to form a fecal cake. The extracted fluid can be collected by passing through the filter gate 118 or sent to another processing system. The fecal cake can be discharged into the drying tunnel 106 via the filter press outlet 128.

[0034] Figure 4B shows a partial cross-sectional view of the filter press 104 shown in Figure 4A. The processed slurry can be received into the solids chamber 114 of the filter press 104 through the filter press inlet 126. As indicated by the horizontal arrow, the piston 116 can compress the slurry against the filter screen 120 to form a cake.

[0035] Figure 4C shows an exploded view of the filter assembly 170 of the filter gate 118. The filter assembly 170 comprises a filter screen 120, a filter support screen 172, a drain spacer 174, a filter press inlet 126, and a check valve 176. The filter assembly 170 may also include seals 178a and 178b of the filter assembly 170. Slurry can be received through the filter press inlet 126 and introduced into the solids chamber 114 via the check valve 176. As shown by the vertical arrow in Figure 4D, the squeegee 122 can move to remove the fecal cake from the filter screen 120 and discharge the fecal cake into the drying tunnel 106.

[0036] Figure 5 shows a more detailed cross-sectional view of the drying tunnel 106 shown in Figure 2B. The fecal cake can be received from the filter press 104 through the drying tunnel inlet 129. The drying tunnel 106 is configured to evaporate and dry the fecal cake by forcing air onto it during transport. The drying tunnel 106 has a proximal end 152 and a distal end 154, and a drying belt 136 extends around rollers 138a, 138b located at the proximal end 152 and the distal end 154, respectively. The drying belt 136 is configured to transport the fecal cake from where it is sent from the filter press 104 to the proximal end 152 to the distal end 154 where it is discharged through the drying tunnel outlet 150. In some examples, the drying tunnel 106 can also receive solids output separately from the concentrator 112.

[0037] If the volume reduction solids treatment system 100 is part of a non-sewerage single-unit toilet system, the concentrator 112 can receive the removed fluid containing salt and / or other particulate solids from the liquid treatment system. Figures 6A and 6B show the concentrator 112 of the volume reduction solids treatment system 100. The concentrator 112 can be a pasteurization and evaporation module that can be connected to the concentration tank of the liquid treatment system. For example, the liquid treatment system may output removed fluid containing solids that cannot be treated by the liquid treatment system. The removed fluid can be reduced in volume by heating the fluid in the concentrator 112. In one example, pressurized air can be introduced into the concentrator so that humidified air and / or off-gas are released and the concentrate remains.

[0038] As shown in Figure 6A, the concentrator 112 may comprise an open concentrator container 180 configured to hold a certain volume of fluid, and a plurality of disks 186 housed within the open concentrator container 180. As shown in the cross-sectional view of Figure 6B, the disks 186 are arranged around a shaft 188 rotatable by a motor 190, so that at least a portion of the disks are wetted by the fluid as the shaft 188 rotates. A heater 192 may comprise a heating coil 194. The heater 192 may be configured such that the heating coil 194 extends into the open concentrator container 180 and heats the volume of fluid contained within the open concentrator container 180. In some examples, the concentrator module 112 may also include a housing 182 positioned above the open concentrator container 180. In some examples, the concentrator module 112 may further comprise air inlets 183 and air outlets 185 that provide airflow over the wet disks 166 and assist in the evaporation of the fluid being concentrated. For example, a blower (not shown) or one or more fans 184 can direct airflow to the concentrator 112. As shown in Figure 6A, the housing 182 may comprise one or more fans 184a to c (individually “fan 184”, collectively “fan 184”) arranged to draw air across a plurality of discs 166 through the concentrator container 180. The air intake 183 may be in the gap between the open concentrator container 180 and the housing 182. In another example, a system blower (not shown) can similarly provide airflow over the plurality of discs 166 to aid in the evaporation of the fluid being concentrated.

[0039] The concentrator 112 can receive a certain amount of removed fluid containing salt and / or other particulate solids from the liquid processing module. An open concentrator 180 can accommodate a certain amount of fluid. The fluid volume can be maintained at a level that does not flow beyond the shaft 188 or hinder rotation. To aid in the evaporation of the fluid, the fluid volume can be heated by heaters 192 and heating coils 194. As the multiple disks rotate through the heated volume of fluid, the air intake 183 can be configured to direct air to the concentrator 112 on the multiple disks 186 so that the fluid evaporates and the received fluid solids remain. The arrows shown in Figure 6A indicate the direction of airflow for evaporation in one example. In another example, the air intake 183 and air outlet 185 can be reversed so that the airflow is provided in the opposite direction. For example, the fan 184 can be configured to draw air through the concentrator 112, or to operate in the opposite direction to blow air into the concentrator 112 and discharge it through the gap between the open concentrator container 180 and the housing 182.

[0040] In one example, the condensed effluent or concentrated volume may be sent to a drying tunnel 106 to remove residual moisture. In one example, the drying tunnel 106 may receive concentrate from the concentrator 112. For example, the drying tunnel 106 may evaporate more than 4 L / day of concentrate. In some examples, the drying tunnel 106 may further be equipped with means for discharging gas. In another example, up to 50% of the volume contained in the open concentrator container 180 may be returned to a buffer tank system or other processing module for further processing.

[0041] Although not shown in the figure, the volume reduction solids processing system 100 may further include valves, pumps, motors, actuators, conduits, switches, sensors, etc. The volume reduction solids processing system 100 may also include a controller 115 (Figure 1) for operating the valves, pumps, motors, actuators, switches, and sensors. For example, the controller 115 may be connected to sensors in the pasteurizer 102 to monitor the temperature and control the heater wrap 142 of the pasteurizer 102.

[0042] Figure 7 shows an exemplary method for reducing the volume of solids as described in this specification. In box 1502, this method may include receiving a batch of fecal slurry into a pasteurizer. For example, the slurry may be received from a homogenizer or a system including a homogenizer, such as a separation and homogenization system. In another example, the slurry may be received into a buffer tank and then sent in batches to a pasteurizer.

[0043] In box 1504, this method may include heating the slurry batch at a high temperature for a certain period of time. This time is sufficient to kill the pathogens and produce slurry with reduced pathogens. For example, a temperature of at least 85°C can be maintained for about 10 minutes to kill the pathogens.

[0044] The slurry, with reduced pathogens, may be transferred to a mechanical dewatering press in box 1506. The dewatering press may include a chamber for receiving the pathogen-reduced slurry and a piston for applying pressure to reduce the volume of the chamber. In box 1508, this method may include compressing the pathogen-reduced slurry in a mechanical dewatering press to separate the liquid phase from the reduced solid excrement. For example, the piston can press the pathogen-reduced slurry against a filter to separate the liquid phase from the reduced solid excrement. In box 1510, the liquid phase may be removed by collecting the liquid or sending it to another system. Compression and removal of the liquid may result in the formation of a fecal cake from the reduced solid excrement in box 1512.

[0045] In box 1514, this method may include discharging the reduced-volume solid excrement onto a conveyor. The fecal cake or cake formed from the reduced-volume solid excrement may be wet and / or sticky. In box 1516, this method may include removing moisture from the reduced-volume solid excrement to form a fecal cake. The fecal cake may be sent to a drying tunnel where air is forced over it to further dry it. In box 1518, this method may include sending the fecal cake to a waste container. For example, the fecal cake may be transported through a drying tunnel via a belt or conveyor over a period of time.

[0046] The volume reduction solids treatment system 100 can be configured for use in a variety of systems and applications. As mentioned above, for example, the volume reduction solids treatment system may be a solids treatment system configured for use in a standalone, non-sewerage toilet system. The volume reduction solids treatment system 100 can be configured to operate and be integrated as part of a single unit toilet system that includes systems such as a liquid treatment system and / or a separation system.

[0047] Figure 8 shows an exemplary schematic diagram of a non-sewerage single-unit toilet system, including a front-end system 1, a buffer tank system 2, a urine and wastewater system 3, and a volume reduction solids treatment system 5. In this example, the volume reduction solids treatment system 5 may comprise the volume reduction solids treatment system 100 described in this specification. For example, the pasteurizer, filter press, and drying tunnel of the volume reduction solids treatment system 5 may be adapted as described in this specification. As shown in this example, the single toilet system may also include an external combustor 6. For example, the external combustor 6 may be part of a non-sewerage single-unit toilet system and may be configured to receive treated solids output from the volume reduction solids treatment system 5.

[0048] In this example, the front-end system 1 captures human waste and separates the mixed waste flow into at least one of a green flow and a brown flow. In some examples, a yellow flow can also be separated. The separated green, brown, and / or yellow flows can be further processed by the buffer tank system 2. The buffer tank system 2 may be configured to output the purified green flow to the urine and wastewater treatment system 3 and the brown flow slurry to the volume reduction system 5, which can produce a cake of solid waste containing feces. A single unit toilet system may further comprise a control unit that includes at least one controller for the operation of the system and / or one or more modules of the system including valves, pumps, motors, sensors, and other devices. A single unit toilet system may be configured to supply a treated liquid output and a treated solid output. For example, the purified and / or treated water may also be used in the flush water system of the front-end 1 or for processing in one or more systems or modules. In some examples, the treated solid waste may be a dry or partially dried cake placed in a waste container accessible to the user. The user can send a dried or partially dried cake to the external combustor 6 for combustion.

[0049] manner

[0050] The following list of exemplary embodiments supports, and is supported by, the disclosure provided in this specification.

[0051] Appearance 1. A solid waste treatment system, A pasteurizer configured to receive a slurry batch and heat the slurry batch at a high temperature for a certain period of time to produce a slurry free of pathogens, wherein the slurry batch contains at least feces, A mechanical dewatering press configured to compress a slurry that does not contain the pathogens and separate the liquid phase from the reduced-volume solid excrement, wherein the reduced-volume solid excrement is formed into a fecal cake. An outlet for removing the aforementioned liquid phase, A solid waste treatment system comprising: a drying tunnel including a conveyor housed within an air duct system, wherein the air duct system is configured to forcibly propel air over the fecal cake within the drying tunnel;

[0052] Appearance 2. The solid waste treatment system according to embodiment 1, wherein the pasteurizer comprises a pipe of a certain length and one or more heaters configured to heat the slurry batch in the pipe.

[0053] Appearance 3. The solid waste treatment system according to embodiment 2, wherein the one or more heaters comprises a plurality of heaters having independent temperature control, and each of the plurality of heaters is wrapped along the length of the piping to define a heating zone in the section of the piping.

[0054] Appearance 4. The solid waste treatment system according to any one of embodiments 1 to 3, wherein the mechanical dewatering press comprises a filter assembly, a chamber, and a piston.

[0055] Appearance 5. The solid waste treatment system according to embodiment 4, wherein the mechanical dewatering press further comprises a filtrate outlet and a squeegee, the squeegee being configured to remove the fecal cake from the mechanical dewatering press.

[0056] Appearance 6. The solid waste treatment system according to embodiment 4 or 5, wherein the filter assembly of the mechanical dewatering press comprises a filter screen.

[0057] Appearance 7. The solid waste treatment system according to embodiment 6, wherein the filter screen is a nylon net of 41 to 160 μm or a stainless steel mesh of 140 to 508 μm.

[0058] Appearance 8. The solid waste treatment system according to any one of embodiments 1 to 7, wherein the drying tunnel dries the fecal cake to a moisture content of 4 to 10%.

[0059] Appearance 9. A solid waste disposal system according to any one of embodiments 1 to 8, further comprising a waste container configured to receive and collect batches of fecal cakes.

[0060] Appearance 10. A method of disposing of human waste, Accepting slurry batches containing feces into a pasteurizer, The method involves heating the slurry batch at a high temperature for a certain period of time, the period of time being sufficient to kill the pathogen, and the method involves heating the slurry batch to produce slurry with reduced pathogen content. The slurry, from which the pathogens have been reduced, is sent to a mechanical dewatering press. The slurry, from which the pathogens have been reduced, is compressed using the mechanical dewatering press to separate the liquid phase from the reduced-volume solid excrement. To remove the aforementioned liquid phase, Forming a fecal cake from the aforementioned reduced-volume solid excrement, Discharging the aforementioned reduced-volume solid waste onto a conveyor, A method for processing human excrement, comprising removing water from the reduced-volume solid excrement to form a fecal cake.

[0061] Appearance 11. A method for processing human waste according to embodiment 10, wherein removing moisture from the reduced-volume solid waste includes forcibly pushing air over the reduced-volume solid waste on the conveyor to provide evaporative drying while being transported in a drying tunnel.

[0062] Appearance 12. The method for processing human excrement according to embodiment 10 or 11, wherein the reduced volume of solid excrement is approximately 20% or less of the volume of the slurry batch.

[0063] Appearance 13. A method for disposing of human waste according to any one of embodiments 10 to 12, wherein removing the liquid phase includes sending the liquid phase to a buffer tank system.

[0064] Appearance 14. A method for processing human excrement according to any one of embodiments 10 to 13, wherein the volume of the slurry batch is approximately 100 mL.

[0065] Appearance 15. A method for disposing of human excrement according to any one of embodiments 10 to 14, wherein the high temperature is at least 85°C.

[0066] Appearance 16. A method for disposing of human excrement according to any one of embodiments 10 to 15, wherein the aforementioned period is approximately 10 minutes.

[0067] Appearance 17. A method for disposing of human excrement according to any one of embodiments 10 to 16, wherein the fecal cake is dried to a moisture content of 4 to 10%.

[0068] Appearance 18. A method for processing human excrement according to any one of embodiments 10 to 17, wherein the dried fecal cake has a number of Escherichia coli (E. coli) of less than 100 per gram.

[0069] Appearance 19. A method for disposing of human excrement according to any one of embodiments 10 to 18, further comprising sending the fecal cake to a waste container. [Examples]

[0070] The following examples are provided to those skilled in the art to provide a complete disclosure and description of how the compounds, compositions, articles, apparatus, and / or methods claimed in this specification are prepared and evaluated, and are intended to be purely illustrative examples of the disclosure, but not intended to limit the scope of what the inventors consider to be the disclosure. Efforts have been made to ensure the accuracy of numerical values ​​(e.g., quantities, temperatures, etc.), but some error or deviation should be taken into consideration. Unless otherwise indicated, parts are parts by weight, temperatures are in °C or ambient temperature, and pressures are atmospheric pressure or near atmospheric pressure.

[0071] Test protocol

[0072] Measurement of Moisture Content in Solids Cake Test Protocol: To measure the moisture content, place a solids fecal cake sample or a portion thereof into an aluminum pan whose container weight has been measured, and weigh the pan and sample on a chemical balance. Dry the sample at 105°C for at least 2 hours, and then weigh the pan and sample again on a chemical balance. The moisture content can be determined using the following formula.

[0073] Extraction of Escherichia coli (E. coli) from solids cake: E. coli (colony-forming units or CFU) is extracted from fecal cake produced by a non-sewerage single toilet system as described herein by following the procedure below. Briefly, sterile phosphate-buffered saline (PBS) is added to the cake and mixed thoroughly. The dry cake will absorb some of the solution, but some of the supernatant liquid should remain in the pipe. This liquid can be used for the biological tests described below.

[0074] To achieve the lowest possible detection limit, a minimal amount of PBS is added to leave enough supernatant to be removed for biological testing. Approximately 1 mL of supernatant is required for E. coli detection using the E. coli detection test protocol described below. If pipetting the liquid is difficult, additional PBS may be added.

[0075] To extract E. coli, prepare a sterile solution of PBS. Weigh the fecal cake or a portion thereof to be examined. Place the weighed fecal cake into a sterile 50 mL centrifuge tube. Add 20 mL of sterile PBS to the centrifuge tube and mix thoroughly using a vortexer until the cake is broken up. Let the sample stand for 5 to 10 minutes to allow the larger solid particles to settle. To aid in the settling of larger particles, optionally centrifuge the sample at 400 rpm for 10 minutes. Centrifugation should not be performed at high speeds, or the E. coli may fall off the supernatant.

[0076] The tube is held at a 45° angle, allowing the supernatant to collect and be easily removed. If the amount of supernatant is insufficient for sampling, an additional 10 mL of PBS can be added, and vortexing and, optionally, centrifugation can be repeated. A 1000 μL pipette tip is used to remove the supernatant, taking care to avoid large particles that could clog the pipette tip.

[0077] Escherichia coli (E. coli) Testing Protocol: Escherichia coli (E. coli) (colony-forming units or CFU) is measured in samples taken according to the “coli extraction from solids cake” procedure described herein. E. coli (E. coli) CFU can be measured by any technique known in the art. Hereinafter, 3M TM PETRIFILM Company (St. Paul, Minnesota, USA) TM E. coli / coliform bacteria counting plates were used. PETRIFILM TM The plate contains modified violet red bile (VRB) nutrients, a cold water-soluble gelling agent, 5-bromo-4-chloro-3-indolyl-D-glucuronide (BCIG, an indicator of glucuronidase activity), and a tetrazolium indicator to facilitate colony counting.

[0078] The sample is mixed or homogenized with a suitable sterile diluent such as Butterfield's phosphate-buffered water, 0.1% peptone water, peptone salt diluent, 1 / 4 Ringer's solution, 0.85 to 0.90% physiological saline, bisulfite-free resin broth (letheen broth), or distilled water.

[0079] PETRIFILM TM Place the plate on a flat surface. Lift the top film on the plate. Dispense 1 mL of the sample suspension prepared as described above into the center of the bottom film of the plate using a pipette held perpendicular to the inoculation area. Wrap the top film over the sample without trapping any air bubbles. 3M TM PETRIFILM TM Use a spreader to spread the inoculation material across the entire growth area of ​​the plate. Remove the spreader and allow the plate to stand for at least 1 minute to allow the gel to form.

[0080] After gel formation, the plates are incubated horizontally in a stack of 20 or fewer plates. Incubation times may vary, and those skilled in the art can select an appropriate incubation time for a given application based on the instructions provided by the manufacturer. After incubation, colonies on the plates can be counted using a standard colony counter or another illuminated magnifying glass. A typical incubation time for detecting Escherichia coli (E. coli) and / or coliforms is 18 to 24 hours at 37°C. Colonies that appear blue to reddish-blue and are associated with trapped gas are counted as confirmed Escherichia coli (E. coli). Colonies should be counted within one hour of removal from the incubator, or they can be stored at -15°C for up to one week before counting.

[0081] For very high-density plates after incubation, it may be necessary to dilute the original sample and perform appropriate volume correction based on the dilution volume to obtain an accurate count.

[0082] PETRIFILM TM To convert CFU per mL to CFU per dry gram, the following formula can be used, where total liquid volume refers to the total volume of PBS added to the initial fecal cake or a portion thereof.

[0083] The features of the embodiments described herein are representative, and in alternative embodiments, certain features and elements may be added or omitted. Unless otherwise indicated, this disclosure is not limited to specific materials, manufacturing processes, etc., and should be understood to be modifiable. Furthermore, the terminology used in this specification is intended solely to describe specific embodiments and is not intended to limit them. Where logically possible, the processes may be performed in a different order.

Claims

1. A solid waste treatment system, A pasteurizer configured to receive a slurry batch and heat the slurry batch at a high temperature for a certain period of time to produce a slurry free of pathogens, wherein the slurry batch contains at least feces, A mechanical dewatering press configured to compress a slurry that does not contain the pathogens and separate the liquid phase from the reduced-volume solid excrement, wherein the reduced-volume solid excrement is formed into a fecal cake. An outlet for removing the aforementioned liquid phase, A solid waste treatment system comprising: a drying tunnel including a conveyor housed within an air duct system, wherein the air duct system is configured to forcibly propel air over the fecal cake within the drying tunnel;

2. The solid waste treatment system according to claim 1, wherein the pasteurizer comprises a pipe of a certain length and one or more heaters configured to heat the slurry batch in the pipe.

3. The solid waste treatment system according to claim 2, wherein the one or more heaters comprises a plurality of heaters having independent temperature control, and each of the plurality of heaters is wrapped along the length of the piping to define a heating zone in the section of the piping.

4. The solid waste treatment system according to claim 1, wherein the mechanical dewatering press comprises a filter assembly, a chamber, and a piston.

5. The solid waste treatment system according to claim 4, wherein the mechanical dewatering press further comprises a filtrate outlet and a squeegee, the squeegee being configured to remove the fecal cake from the mechanical dewatering press.

6. The solid waste treatment system according to claim 4, wherein the filter assembly of the mechanical dewatering press comprises a filter screen.

7. The solid waste treatment system according to claim 6, wherein the filter screen is a nylon net or stainless steel mesh.

8. The solid waste treatment system according to claim 1, wherein the drying tunnel dries the fecal cake to a moisture content of 4 to 10%.

9. The solid waste disposal system according to claim 1, further comprising a waste container configured to receive and collect batches of fecal cakes.

10. A method of disposing of human waste, Accepting slurry batches containing feces into a pasteurizer, The method involves heating the slurry batch at a high temperature for a certain period of time, the period of time being sufficient to kill the pathogen, and the method involves heating the slurry batch to produce slurry with reduced pathogen content. The slurry, from which the pathogens have been reduced, is sent to a mechanical dewatering press. The slurry, from which the pathogens have been reduced, is compressed using the mechanical dewatering press to separate the liquid phase from the reduced-volume solid excrement. To remove the aforementioned liquid phase, Forming a fecal cake from the aforementioned reduced-volume solid excrement, Discharging the aforementioned reduced-volume solid waste onto a conveyor, A method for processing human waste, comprising removing moisture from a fecal cake in a drying tunnel.

11. A method for processing human waste according to claim 10, wherein removing moisture from the reduced-volume solid waste includes forcibly pushing air over the reduced-volume solid waste on the conveyor to provide evaporative drying while being transported in a drying tunnel.

12. The method for processing human excrement according to claim 10, wherein the volume-reduced solid excrement is about 20% or less of the volume of the slurry batch.

13. The method for processing human waste according to claim 10, wherein removing the liquid phase includes sending the liquid phase to a buffer tank system.

14. The method for processing human excrement according to claim 10, wherein the volume of the slurry batch is approximately 100 mL.

15. The method for disposing of human excrement according to claim 10, wherein the high temperature is at least 85°C.

16. The method for disposing of human excrement according to claim 10, wherein the aforementioned period is approximately 10 minutes.

17. The method for disposing of human excrement according to claim 10, wherein the fecal cake is dried to a moisture content of 4 to 10%.

18. The method for processing human excrement according to claim 10, wherein the dried fecal cake has a number of Escherichia coli (E. coli) of less than 100 per gram.

19. The method for disposing of human excrement according to claim 10, further comprising sending the fecal cake to a waste container.

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