Liquid-solid separator in sanitation

Abstract

The separator serves to separate solid and liquid waste from defecation and urination, for use especially in the field of sanitation and fecal waste management. Liquids and solids are separately channeled out of the separator body through different outlets, and can be channeled into separate systems. The present invention can realize instant separation of solid and liquid waste, achieving a lower liquid to solid ratio in fecal containment devices, lower pathogenic loads in the liquid waste, and enabling separate management of liquids and solids. In certain embodiments, an effluent treatment method is attached to treat the captured liquids. In certain embodiments, a solid treatment method is attached to treat the captured solids.

Description

[0001] LIQUID-SOLID SEPARATOR IN SANITATION

[0002] FIELD OF THE INVENTION:

[0003] The present invention relates to the separation of liquids and solids in sanitation. More particularly, one embodiment of this patent application relates to liquids-solids separation in sanitary plumbing systems and in the fecal waste management field.

[0004] BACKGROUND OF THE INVENTION

[0005] Liquid contents, together with solid waste contents such as fecal wastes, are typically mixed and conveyed in the same system in sanitary plumbings. Liquid, such as water, functions as a medium to carry and displace waste (including urine, feces, and cleansing water) in plumbing systems. The displaced mixture of liquids and solids typically goes through sewer pipes. However, this way, solids that are high in pathogen burden, such as feces, are mixed with liquids that are less contaminated with lower pathogen burden.

[0006] In the field of sanitation in particular, fecal waste mixtures comprising fecal solids, urine, flush water, typically goes through sewer pipes, or directly into containment systems such as pit latrines. These sanitation systems rely on a proper on-site containment system as well as reliable emptying and transportation mechanism to prevent environmental contamination by fecal matter and to ensure continued toilet facility operation. However, the high liquid content in fecal wastes mixture due to flushing with water, increases the volume of the overall fecal waste mixture that needs to be emptied, transported and treated. The liquid-solid ratio (LSR) in the fecal waste mixture can be as high as 96% in pit latrines. If the content of the liquid solid ratio is decreased, a domino effect will be resulted and can positively impact the different processes in fecal waste management comprising emptying, transportation and treatment steps by reducing the volume of the fecal wastes mixture. Separating liquids content from solid fecal matter allows differentiated management of liquids and solid fecal matter. Liquids, comprising urine and flush water, which are typically of lower pathogen burden, can be disposed onsite safely directly or with minimum intervention. Solids, comprising feces and dry-cleaning material, can be contained within any designated containment systems, such as latrine pits, until removal and onward transportation and treatment.

[0007] Related prior arts, including urine-diversion dehydration toilets (LIDDT) and urine-diverting (UD) interface, have an intent of separating urine from feces to enable differentiated management of urine and solid fecal matter. LIDDT is a type of system that requires a special UD toilet interface. The separation of solids from urine can be achieved with various apparatus and methods, most prominently through introducing an UD interface which has two holes instead of one hole (as in a typical toilet bowl or squatting toilet pan), where urine is collected in the anterior containment whereas feces and dry cleaning material (i.e. toilet paper) are collected in the posterior containment, mirroring the human ergonomics. The posterior containment for collecting feces is intended to be kept as dry as possible, one of the functions of which is to enable pathogen reduction and stabilization on-site.

[0008] However, UDDTs using special UD interfaces require the need for user behavior change in order to use the UDDTs and the UD interfaces correctly; and UDDTs are not appropriate for users who are “washers”, who wash themselves after urination or defecation. One type of squatting UD interface that is intended to be used among washers, comprises 3-holes, with the most posterior hole added for collecting anal cleansing water; yet the UD interface is not user-friendly since the toilet user will need to wiggle backward for cleansing after defecation. The undesirable result of deploying UDDTs and UD interfaces in certain cultural practices such as the washers’ culture, is the ineffective separation of liquid content from solid excreta, further leading to an excessively moist and even watery containment for solid excreta, rendering the subsequent intended treatments of the solid excreta ineffective.

[0009] Another related prior arts, is solid-liquid separator (AU598593B2) which utilizes the centrifugal and gravitational force along a conically shaped surface, where differentiated helical flow velocity of liquid and solid separate liquid from solid. The inlet pipe directs the liquid into a cone-shaped surface. The liquid will utilize its velocity in creating a circular flow path in the funnel shaped surface, where the solid waste will be directed toward the center of the funnel. There are more recent filing of patents (such as CN112867568A) based on the mentioned separator where some components are removed or modified, but also makes use of centrifugal force. However these systems require a certain minimum space vertically and minimum footprint, certain momentum of flush water and a certain angle in connecting sewer pipes in order to function effectively. Volume needed and configuration of pipes are a limitation, including in the context of limited space.

[0010] Another category of related prior arts, including sewer pipe connections in buildings and clusters of buildings, have the intent of gathering fecal wastes mixture and transfer to another location for waste management. However, the sewer pipes convey a mix of fecal solids and liquids, creating a mixture of high pathogen burden that needs to be treated.

[0011] Therefore, there is a need in the art for a liquid-solid separator in sanitation that overcomes the challenge of overloading of effluents during conveyance and overloading of fecal waste mixture of high pathogen burden in subsequent treatment facilities. Such a liquid-solid separator when used in a fecal waste management system should reduce environmental contamination due to leaching or overflow of the pit latrine, enable the volume of fecal waste mixture in pit latrines and other fecal sludge containment systems to be reduced, and thereby decreases emptying frequency and results in decreased overall emptying costs of these containment systems.

[0012] SUMMARY OF THE INVENTION

[0013] According to one aspect of the invention, there is provided a solid-liquid separation apparatus comprising an inlet opening that leads from a pipe with a downward slope, which is configured to receive a mixture of liquids and solids. The apparatus includes an outlet opening positioned to direct solids downward by gravity, at least one outlet opening for liquids, and a body that connects the inlet opening and the outlet opening(s). Additionally, the apparatus comprises a filter within the body. The filter is a physical barrier oriented transversely to the direction of flow, which is adapted to allow liquids to pass through to the outlet opening for liquids, while blocking solids that are larger than the voids of the filter. The filter diverts solids toward the outlet opening for solids.

[0014] In accordance with an embodiment of the present invention, the apparatus further comprises a second filter that is oriented along the axis of flow next to the inlet opening and configured to block solids larger than the void from passing through.

[0015] In accordance with an embodiment of the present invention, the apparatus further includes a directional surface that abuts the body’s wall so that a continuous plane is formed with the wall and continues to span outward from the body.

[0016] In accordance with an embodiment of the present invention, the apparatus includes a second outlet for liquid after the second filter.

[0017] In accordance with an embodiment of the present invention, the apparatus includes a receiver for liquid, and the receiver is located on the exterior of the body.

[0018] In accordance with an embodiment of the present invention, the filter is a brush with filaments oriented parallel to each other.

[0019] In accordance with an embodiment of the present invention, the filter comprises at least one piece of plastic sheet cut into stripes.

[0020] In accordance with an embodiment of the present invention, the second filter is a solid plate with voids ranging from, but not limited to, 1 mm to 5mm wide.

[0021] According to another aspect of the invention, there is provided a solidliquid separation apparatus comprising an inlet opening configured to receive a mixture of liquids and solids, an outlet opening positioned to direct solids downward by gravity, at least one outlet opening for liquid, and a horizontal pipe with a slope connected to the inlet opening. The apparatus also includes a filter within the body. The filter is a physical barrier oriented along the axis of flow and is adapted to allow liquids to pass through to the outlet opening for liquids while blocking solids larger than the voids of the filter, and diverting solids toward the outlet opening for solids.

[0022] In accordance with an embodiment of the present invention, the apparatus further comprises a second filter oriented transversely to the direction of flow, which blocks solids larger than the void from passing through.

[0023] In accordance with an embodiment of the present invention, the apparatus further includes a directional surface that abuts the wall of the body so that the upper edge is flush with the wall, and the surface continues to span outward from the body.

[0024] In accordance with an embodiment of the present invention, the filter is a solid plate with voids of spacing between, say, 1 mm to 5mm.

[0025] In accordance with an embodiment of the present invention, the second filter is a brush with filaments oriented roughly parallel to each other.

[0026] In accordance with an embodiment of the present invention, the second filter comprises at least one piece of plastic sheet cut into stripes.

[0027] According to yet another aspect of the invention, there is provided a method of separating liquid from solid, which comprises receiving a mixed waste stream of liquids and solids from a horizontal pipe with a downward slope. The method further differentiates liquid from solid particles at a junction based on their linear momentum, where fast-flowing liquid is captured within an open volume of the body at a further distance from the end of the pipe, and solids are captured at a closer distance. In addition, a permeable layer is located after the end of the pipe, oriented transversely to the pipe’s axis, and adapted to capture and block solids while allowing the liquids to pass through. In accordance with an embodiment of the present invention, the method further includes a step of diverting liquid using a directional surface that extends from the end of the horizontal pipe, bends downward along a vertical axis, and extends outward from the axis, with the liquid flowing along the undersurface of the directional surface.

[0028] In accordance with an embodiment of the present invention, the permeable layer is located along the lowest point of the pipe’s circumference. The method further includes the receiver located under the permeable layer and a step of diverting liquids into the receiver through the permeable layer, which excludes solids from entering the receiver.

[0029] In accordance with an embodiment of the present invention, the method further comprises the use of a retainer selected from, but not limited to, a settling tank, anaerobic reactor, aerobic reactor, sand filter, filter, pre-drying bed, constructed wetland, or solid presser.

[0030] In accordance with an embodiment of the present invention, the method further comprises a urine treatment unit selected from, but not limited to, a struvite reactor tank, electrolysis, or pyrolysis.

[0031] In accordance with an embodiment of the present invention, the method further comprises a dewatering unit selected from, but not limited to, a drying bed, planted drying bed, worm-bed, dewatering chamber, settling tank, or combustion chamber.

[0032] In accordance with an embodiment of the present invention, the liquid outlet is connected further to another separator’s liquid outlet, and the solid outlet is connected to another separator positioned vertically at a distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] So that the manner in which the above recited features of the present invention maybe understood in detail, a more particular to the description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, the invention may admit to other equally effective embodiments. These and other features, benefits and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

[0034] FIG. 1 is a cross-section illustration view of the liquid-solid separator designated as 100 in accordance with an embodiment of the present invention;

[0035] FIG. 2 is a cross-section illustration view of the liquid-solid separator designated as 200, in accordance with a certain embodiment of the invention;

[0036] FIG. 3 is a cut-out sectional illustration view of a partial part of liquid-solid separator, showing a tongue-like direction plane, in accordance with an embodiment of the invention;

[0037] FIG. 4 is a cut-out sectional illustration view of a partial part of liquid-solid separator, showing a tongue-like direction plane, in accordance with another embodiment of the invention;

[0038] FIG. 5 is a cut-out sectional illustration view of a partial part of the liquidsolid separator, showing one mechanism of filter, in accordance with an embodiment of the invention; and

[0039] FIG. 6 is a cut-out sectional illustration view of a partial part of the liquidsolid separator, showing one another mechanism of filter, in accordance with an embodiment of the invention.

[0040] DETAILED DESCRIPTION OF THE DRAWINGS

[0041] The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description.

[0042] While the present invention is described herein by way of example using embodiments and, those skilled in the art will recognize that the invention is not limited to the embodiments of described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that and description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes.

[0043] This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention. Referring to FIG. 1 , in one embodiment, a waste mixture of liquids and solids from the toilet pan or toilet bowl (both liquids and solids) enters the separator 100 via the inlet opening 101 and then channel 111 (a “receiver”), which may have an inclination from the horizontal, leading the wastes to the body 104 (a receiver). Slow-flowing liquids flowing along channel 111 pass downward through a filter, which is a physical barrier in the location of 121 , and said liquids enter into cavity 112 (a “receiver”). Fast-flowing liquids (typically from flushing down the toilet interface) pass through filter surface 121 and enter into body 104, and further enter through filter region 122 into cavity 113. By gravity, the liquids that can pass across the filter surface 121 , as well as the liquids that flow along the surface and the underside of directional surface 130, enter into the conveyance channel 114, which acts as a receiver. The liquids that leave channel 111 into body 104 and then pass through filter region 122 can be received at cavity 113 and exit through opening 103. Overall, all the liquids in conveyance channels will exit through the liquid outlet opening 103 by gravity.

[0044] In certain embodiments, said conveyance channels, also a “receiver”, are on the exterior of the body. In certain embodiments, said conveyance channel can be on the interior of the body, as shown in FIG. 2 as channel 215, which is also a “receiver”. In certain embodiments, said conveyance channel can be a pipe or a tube leading liquids to a separate outlet opening. In certain embodiments, said pipe can be further connected to a retainer system or treatment system before leading to a final outlet opening before discharge. In accordance with an embodiment of the present invention, the system may further comprising a urine treatment unit placed after the outlet opening for liquids, selected from, but not limited to, struvite reactor tank, electrolysis, and pyrolysis.

[0045] Flowing down along the underside of said directional surface, the liquids enter into another cavity, which is also referred to as a “receiver,” such as conveyance channel 114 in FIG. 1 , reservoir-like channel 215 in FIG. 2, and cavity 412 formed by a wall 412, while solids drop by gravity or initial momentum when exiting the toilet bowl or toilet pan. The receivers can be located both internally within the separator’s body or externally of the separator’s body. In some embodiments, the receiver may be connected to a standard tube and leads to another outlet that which may be connected with an external system such as a urine reactor etc.

[0046] In certain embodiments, the separator includes an opening 105 pointing upwards from the body to serve as a clean-out, allowing access from above a pit slab for inspection, unclogging, and cleaning, as indicated in FIG. 1.

[0047] In certain embodiments, the ability to collect liquids with the physical barrier (filter) region 122 is increased by increasing the height of the body 104 at the region below the inlet opening and above the outlet opening.

[0048] In certain embodiments of filtering done by physical filtering, the filter (physical barrier) is in the form of a plate with voids, such as filter 521 , having parallel gaps with parallel beams, and located in channel 505, as shown in FIG. 5. In certain embodiments, said plate is located along the wall of a pipe where the size of the plate is carved out. The plate may be detachable and placed within said carved-out space in one embodiment. The plate may be built into the pipe in another embodiment. Mixed waste comprising solids and liquids enters from opening 501 , flows through the separator body 505, and reaches the region of filter 521 . Liquids drop down into another cavity in the form of channel 506 in FIG. 5 by way of physical filtering, while solids flow along the pipe, carried by the momentum of the liquid. Solids may flow by gravity alone, without initial momentum. In some embodiments, following the flows along channels 505 and 512, liquids exit via opening 503, and solids exit via opening 502.

[0049] In certain embodiments of filtering done by physical filtering, the filter (physical barrier) is in the form of brushes, such as filter 623 in FIG. 6, having a vertical orientation. The brushes may be made of filaments that are bundled into one brush, which further may be arranged in one or more layers. When liquids and mixed wastes of liquids and solids hit the brushes, liquids pass through the brushes and enter into a subsequent cavity 613. The brushes may be held by nozzle heads that can be detached from body 604. The brushes may be an integral part of the body 604. The filter region (physical barrier region) 622 may include rigidly anchored material in the form of columns with gaps, such that larger and heavier solids that can pass through the brushes do not pass the rigid material. The rigidly anchored material may be in the form of mesh and sieve; it may be detachable in some embodiments and an integral part of the body 604 in other embodiments.

[0050] Overall, the filters perform their function of blocking solids while allowing liquids to pass through. This is achieved by means of physical barriers, wherein solids larger than predetermined sizes of the voids of said barriers are blocked, but liquids can pass through. The filters can take different forms, sizes, shapes, and orientations. Examples of such forms include a surface of mesh, a surface with slits, a surface with a matrix of holes, an array of columns, and an array of bars at different orientations, brushes, and plastic sheets cut into stripes with loose ends. The orientation of the plane of said filter can be vertical (as shown in FIG. 1 ) or tilted at an angle (as shown in FIG. 2).

[0051] In general, the outlets are located lower than the inlet(s). The body that connects the inlet(s) to the outlets can take various sizes and shapes, even taking the geometry of the intersection (boolean) of inlet and outlet pipes. The liquid-solid separator can be configured with one outlet for solid wastes and at least one outlet for liquids, enabling at least one subsequent liquid management system.

[0052] In certain embodiments, the liquid-solid separator is installed in an offset pit latrine in connection with a pipe from the toilet interface, and a liquid outlet is connected to a liquid effluent filter containing layers of granules made from various materials. Said effluent filter works on removing pathogens using physical filtration and chemical reactions. The purpose of the effluent filter is to improve the effluent liquid quality over the existing leaching found in unlined and open-bottomed latrine pits, which may be made of concrete rings. The treated effluent can be released directly into the environment using a perforated pipe installed beneath the soil, with the option for additional treatment if needed. In certain embodiments, the liquid outlet(s) and solid outlet each empties into a respective pit, tank, or other containment system. In certain embodiments, the liquid outlet(s) will empty into a pit, while the solid outlet is connected to a containment system, such as a container, for further treatment. In certain embodiments, the liquid-solid separator’s liquid outlet is connected to an anaerobic baffled reactor before liquid discharge. In other embodiments, the liquid-solid separator’s liquid outlet is connected to a settling tank before the liquid is discharged. In yet other embodiments, the solid outlet is connected to a container below; when the container is filled, it can be emptied or replaced with an empty container. The solid outlet(s) may lead to a treatment technology suitable for thick fecal sludge, such as drying beds and planted drying beds.

[0053] In another embodiment, the liquid-solid separator inlet is connected to an S-trap pipe to a flush toilet pan. In certain embodiments, the liquid-solid separator inlet is connected to a toilet interface with minimal distance, without an offset pipe from the toilet room.

[0054] In certain embodiments, the liquid-solid separator is installed in multistorey buildings, where a sewer pipe connected to a toilet room is further connected to the liquid-solid separator, wherein the solid outlets and liquid outlets are separately connected with pipes that convey the waste content to different subsequent management systems, such as a sewer network and treatment facility.

[0055] In accordance with an embodiment of the present invention, the system further comprises a dewatering unit connected after the solid outlets. The dewatering unit may be selected from, but not limited to, a drying bed, planted drying bed, worm-bed, dewatering chamber, settling tank, or combustion chamber.

[0056] Overall, the invention embodiments applied to non-sewered settings enable liquid-solid separation with minimal user behavioral change, which is typically required in prior arts (e.g., UDDTs and UD interfaces). The separator enables dryer content to exit the solid outlet, making it compatible with various common and specialized containment and treatment systems. In sewered settings, the invention allows for liquid-solid separation that leads to separate conveyance and subsequent separate liquids and solids management, which has not been possible in prior arts (e.g., sewer pipes in buildings and sewer networks). This enables lower volume flow and lower pathogen burden for treatment.

[0057] In addition to its broad applicability, the invention presents a significant technical advancement over existing solutions by employing a unique combination of physical barriers, directional surfaces, and customizable filter configurations. Unlike prior systems that either rely heavily on user interaction or fail to effectively manage the separation of high-moisture waste, this invention introduces a non- obvious solution that utilizes gravity, flow dynamics, and specially designed traps to achieve separation with minimal intervention. The invention’s use of brush filters, perforated plates, and adjustable directional surfaces allows for more efficient liquidsolid separation across varying flow conditions, making it technically superior to conventional methods that are less adaptable. Furthermore, the ability to integrate advanced treatment options, such as anaerobic baffled reactors or effluent filters, highlights the flexibility and forward-thinking design of the system, which is equipped to handle both high-volume urban applications and resource-limited rural settings. These technical features, coupled with the invention’s capacity to reduce pathogen loads and improve overall waste management efficiency, demonstrate its clear innovation and uniqueness, setting it apart from prior art in the sanitation field.

[0058] The following exemplary embodiments describe various possible configurations of the liquid-solid separator, illustrating how different components interact to achieve efficient waste separation. These embodiments are provided as examples and are not intended to limit the scope of the invention. The figures referenced below demonstrate how different parts of the invention, such as the inlet, body, filters, and directional surfaces, work together in various configurations to separate liquids and solids. The specific features, arrangements, and methods described herein can be applied in different combinations, depending on the particular requirements of the application.

[0059] In some embodiments, the invention comprises the features in FIG. 5, wherein inlet opening 501 leads mixed wastes to channel 505, which also is referred to as a “body”; filter (physical barrier) 521 traps liquid to channel 512, which also is referred to as a “receiver”; and then solid wastes exit via outlet opening 502 and liquids exit via outlet opening 503.

[0060] In some embodiments, the invention comprises the features in FIG. 3, wherein inlet opening 301 leads solids towards body 304 and towards outlet opening 302, and slow-flowing liquids along tongue-like directional surface 330 which guides slow-flowing liquid towards separate cavity 303, which also is the region of a “receiver”.

[0061] In some embodiments, the invention comprises the features in FIG. 4, wherein inlet opening 401 leads solids towards body 411 , also referred to as a “pipe” or “channel”, and towards outlet opening 402, and liquids along tongue-like directional surface 430, which guides slow-flowing liquid towards separate cavity 403, which also is the region of a “receiver”. In some embodiments, said cavity is formed by a wall 412 at the exterior of body 411. The directional surface extends concentrically outwards from the body.

[0062] In some embodiments, the invention comprises features in FIG. 4 and FIG. 5, wherein waste enters via opening inlet before 501 into channel 505, also is referred to as a “body”, and filter (physical barrier) 521 traps liquid to channel (receiver) 512 and leads to opening 503, while a tongue-like directional surface 430 is located along channel 505 and leads liquid to a cavity (a receiver) and subsequently to an exit opening; whereas solids fall down along body 505 and 411 and exit towards opening 402 and 502.

[0063] In some embodiments, the invention comprises features in FIG. 3 and FIG 5, wherein wastes enter via inlet opening 301 , and tongue-like directional surface 330 guides slow-flowing liquids towards 303 (region for a receiver); whereas fastflowing liquids with solids hit filter region 622 that is vertically inclined, and liquids passes through the brushes into another cavity, while solid drops down towards an outlet opening. In some embodiments, the orientation of body 505 is vertically inclined , in some embodiments horizontally inclined. In some embodiments, the orientation of body 411 is vertically inclined , in some embodiments horizontally inclined.

[0064] In some embodiments, the invention comprises features in FIG. 3 and FIG. 6, wherein wastes enters via opening inlet 301 , and slow-flowing liquids slide down the undersurface of tongue-like directional surface 330 and flow towards cavity (region for a receiver) 303. This may be referred as a "liquid trap", that can be further added within the body, or after the outlet for solids for additional liquid capturing. The "liquid trap" comprises a directional surface that abuts a wall of the body, extends along a vertical axis and extends outward. Liquids flow along the undersurface of said directional surface and the liquids are then received by a receiver that leads to a liquid outlet. In other words, liquids are trapped into the receiver, while solids continue their momentum (downward) by gravity. This liquidtrapping mechanism is a way of filtering solid particles from liquids while capturing additional liquids that are missed from any previous filters.

[0065] It will be understood to a person skilled in the art that the combinations described above are only exemplary not exhaustive. Some other combinations may also be formed without requiring application of any inventive skill.

[0066] The present invention offers several notable advantages, some of which are listed below:

[0067] Efficient Liquid-Solid Separation: The invention ensures rapid and efficient separation of liquids and solids, reducing the overall moisture content in the solid waste. This facilitates easier handling, storage, and transportation of solid waste.

[0068] Compatibility with Existing Systems: The invention can be retrofitted into existing sanitation systems, including, but not limited to, pit latrines, septic tanks, and sewer networks, vertical wetland, horizontal wetland, polishing pond etc., without requiring major infrastructural changes. This allows for seamless integration in a wide range of applications.

[0069] Reduced Liguid-to-Solid Ratio: By separating liquids and solids more effectively, the invention reduces the liquid-to-solid ratio, which decreases the overall volume of waste that requires treatment. This directly leads to cost savings in transportation, emptying, and treatment processes.

[0070] Lower Greenhouse Gas emissions: By preventing solid waste from being submerged in liquid, the present invention inhibits the anaerobic process and promote aerobic degradation of fecal matter, resulting in up to seven times lower greenhouse gas emissions.

[0071] Lower Pathogen Load in Liquids The invention isolates liquids with is lower total solid in the liquid, which is translated into lower BOD, COD and pathogens, allowing for easier and safer onsite or downstream treatment. This reduces the environmental and public health risks associated with untreated waste disposal.

[0072] Flexibility in Filter and Barrier Design: The inclusion of various customizable filter options (e.g., brush filters, perforated plates, plastic sheet cut into stripes) and directional surfaces allows the system to be tailored for different flow rates and waste characteristics, making it highly versatile in diverse sanitation scenarios.

[0073] Reduced Maintenance Frequency: The efficient separation of waste decreases the frequency of emptying and maintenance operations for both liquid and solid containment systems, leading to lower operational costs and less frequent service interruptions.

[0074] Adaptability to Multiple Settings: The invention is suitable for both high- density urban environments and resource-constrained rural areas. Its ability to function in both sewered and non-sewered settings makes it a highly flexible solution for global sanitation challenges.

[0075] Integrated Treatment Options: The invention can be coupled with additional treatment systems such as urine fuel cells, anaerobic baffled reactors, effluent filters, or drying beds. This simply results in decreasing the volumes, residence time and therefore, their capital investment, thereby enabling a complete and customizable waste management solution that goes beyond basic separation.

[0076] Environmental Benefits: In treatment, effluent stability (BOD & COD) is big risk. The present invention can do 99% reduction in BOD content, thereby reducing the risk of contamination.

[0077] Scalable and Cost-Effective: The modular design and low infrastructure requirements make the invention scalable, allowing it to be implemented cost- effectively at different scales, from individual households to larger communal or urban sanitation systems.

[0078] Enhanced Waste Treatment Efficiency: By enabling the separation of liquids and solids early in the waste management process, the invention improves the efficiency of subsequent treatment steps, such as composting or vermicomposting, which rely on reduced moisture content in the solid waste.

[0079] In this manner, the present invention provides a comprehensive and innovative solution to the challenges of liquid-solid separation in sanitation systems.

[0080] In general, the configuration of the invention and its embodiments described in this disclosure can result in varying amounts of liquids being directed into the solid outlet(s), and of solids into the liquid outlet(s). Various embodiments of the invention do not necessarily achieve complete liquids-solids separation, and it is of matter of fact that liquid wastes containing certain pieces of solid wastes also contain a certain level of liquid content. The waste content and separated waste content described in this disclosure can also comprise varying ratios of liquids to solids.

[0081] Descriptions like “high-flow”, “fast-flowing” and “low-flow”, “slow-flowing” are not limited to the wetted perimeter in the pipe and speed of liquid flow. Low-flow- or slow-flowing conditions may exist where the wetted perimeter is small, high-flow- or fast-flowing conditions may exist where the wetted perimeter is large.

[0082] “Waste” in general can also contain solid waste like plastic, tissues, that are not human excreta. Descriptions like “cavity” in general can refer to a conduit, pipe, a semi- or fully enclosed volume of varying sizes and shapes. Descriptions like “channel” refers to a surface, a group of surfaces or a continuum of surfaces that can convey liquid regardless of its sizes and shapes. “Enclosures” should not be construed only as water-tight volume, and should not exclude partially enclosed volume. Descriptions like “receiver” can refer to any cavity where substances stay or pass through. Descriptions like “inlet” and “inlet opening” refer to the location of receiving certain substances, and do not imply the absence of connectors or apparatus before it, and “outlet” and “outlet opening” refer to the location of the exit of certain substances through it, and do not imply the absence of connections or apparatus after it. Descriptions like “physical barriers” and “filters” refer to physical material that present an ability as a blockade to block certain substances completely and partially and allow certain substances to pass through completely. “Permeable layer” refers to materials that block certain substances from passing. Descriptions like “toilet interface” refers to the toilet bowl, squatting pan, a hole on the floor etc. where users interact during defecation. Descriptions like “first”, “second”, “third” do not denote sequence of process, but to distinguish between elements of similar nature.

[0083] The present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art. The principles associated with the various embodiments described herein may be applied to other embodiments. The specific embodiments and applications thereof described above are for illustrative purposes only and do not preclude modifications and variants encompassed by the scope of the present invention and the following claims.

Claims

CLAIMSWhat is claimed:1 . A solid-liquid separation apparatus, comprising: an inlet opening leading from a pipe with a downward slope, configured to receive a mixture of liquids and solids; an outlet opening positioned to direct solids downward by gravity; at least one outlet opening for liquids; a body connecting the inlet opening and the outlet opening(s); and a filter within the body; wherein the filter is a physical barrier oriented transversely to a direction of flow, adapted to allow liquids to pass through to the outlet opening for liquids while blocking solids of sizes bigger than voids of the filter from passing through, and diverting solids towards outlet opening for solids.

2. The apparatus according to Claim 1 , further comprising: a second filter oriented along the axis of flow next to the inlet opening, configured to block solids of sizes bigger than the void from passing through.

3. The apparatus according to Claim 1 , further comprising: a directional surface that abuts a wall of the body so that a continuous plane is formed with said wall, and continues to span outward from the body.

4. The apparatus according to Claim 2, further comprising a second outlet for liquid after the second filter.

5. The apparatus according to Claim 2, further comprising a receiver for liquid, and the receiver is located on the exterior of the body.

6. The apparatus according to Claim 1 , wherein the filter is a brush with filaments oriented parallel to each other.

7. The apparatus according to Claim 1 , wherein the filter comprises at least one piece of plastic sheet cut into stripes.

8. The apparatus according to Claim 2, where in the second filter is a solid plate with voids of spacing ranging from 1 mm to 5mm wide.

9. A solid-liquid separation apparatus, comprising: an inlet opening configured to receive a mixture of liquids and solids;an outlet opening positioned to direct solids downward by gravity; at least one outlet opening for liquid; a horizontal pipe with a slope connected to the inlet opening; and a filter within the body; wherein the filter is a physical barrier oriented along an axis of flow, adapted to allow liquids to pass through to the outlet opening for liquids while blocking solids of sizes bigger than the filter’s void from passing through, and diverting solids towards outlet opening for solids.

10. The apparatus according to Claim 9, further comprising: a second filter oriented transversely to the direction of flow, which blocks solids of sizes bigger than the void from passing through;11 . The apparatus according to Claim 9, further comprising: a directional surface that abuts a wall of the body so that a continuous plane is formed with the wall, and continues to span outward from the body.

12. The apparatus according to Claim 9, where in the filter is a solid plate with voids of spacing of 1 mm to 5mm.

13. The apparatus according to Claim 10, wherein the second filter is a brush with filaments roughly parallel to each other.

14. The apparatus according to Claim 10, wherein the second filter comprises at least one piece of plastic sheet cut into stripes.

15. A method of separating liquid from solid, comprising: receiving mixed-waste stream of liquids and solids from a pipe with a downward slope; differentiating liquid from solid particles through a junction on the basis of linear momentum, wherein free-flowing liquid is captured within an open volume of a body at a further distance from the end of the pipe, and solids are captured at a closer distance; and locating a permeable layer after the end of the pipe, a permeable layer being oriented transversely to an axis of the pipe, and capturing and blocking the solids from entering through the permeable layer while allowing the liquids to pass.

16. The method according to claim 15, further comprising: diverting liquid with a directional surface, wherein the directional surfaceextends from the end of the downward pipe, bends downward along a vertical axis, and extends outward from the axis, with the liquid flowing along an undersurface of the directional surface.

17. The method according to claim 15, wherein: the permeable layer is located along the lowest point of the pipe circumference; and the receiver is located under the permeable layer; and diverting liquids into a receiver through a permeable layer which excludes solids from entering into a receiver.

18. The method according to claim 15, further comprising a step of connecting a retainer system before leading to a final outlet opening before discharge, wherein the retainer system is selected from a settling tank, anaerobic reactor, aerobic reactor, sand filter, filter, pre-drying bed, constructed wetland, and solid presser.

19. The method according to claim 15, further comprising step of connecting a urine treatment unit with an outlet opening for liquids, wherein the urine treatment unit is selected from struvite reactor tank, electrolysis, and pyrolysis.

20. The method according to claim 15, further comprising a step of disposing a dewatering unit after an outlet opening for solids, wherein the dewatering unit is selected from a drying bed, a planted drying bed, a worm -bed, a dewatering chamber, a settling tank, a combustion chamber, and a further liquid-trap.

21. The method according to claim 15, further comprising a step further connecting a liquid outlet to connected to another separator’s liquid outlet, and a solid outlet to another separator vertically at a distance.

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