WO2020144658A1

WO2020144658A1 - Fecal sludge treatment plant and processes thereof

Info

Publication number: WO2020144658A1
Application number: PCT/IB2020/050207
Authority: WO
Inventors: Dushyant DUBEY
Original assignee: Dubey Dushyant
Priority date: 2019-01-11
Filing date: 2020-01-11
Publication date: 2020-07-16

Abstract

The present embodiment herein provides a fecal sludge treatment plant (100). The treatment plant includes an inlet pipe through which a semi-solid fecal sludge is received in the plant, a gritt screening chamber (104) to screen the incoming sludge having particle size greater than 10mm, an anoxy chamber (108) to reduce nitrogen content in the sludge, a primary lamella clarifier (110) which includes an oil and grease separator to separate oil and grease from the sludge to obtain more liquid form of the sludge, an aeration chamber 1 and 2 (112,114) to dose off 50 to 80% air, thereby decreasing biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the liquid, a secondary lamella (116) to obtain a treated liquid, wherein the settleable solids drains to a sludge drawing bed and remaining water to the biological digester (106), a holding sump (118) ozonize the liquid for disinfection, a calcium carbonate sand filter (120) to maintain the PH value of the liquid, an activated carbon filter (122) which absorbs the odors and other absorbable impurities from the liquid, and a 5 micron filter (124) to remove the impurities lager than 5 micron and obtain a treated liquid acceptable for industrial consumption.

Description

FECAL SLUDGE TREATMENT PLANT AND PROCESSES THEREOF

BACKGROUND

Technical Field

The embodiments herein generally relate to a fecal sludge treatment plant and more particularly to a process of treatment of fecal sludge, in which the sludge is in slurry or semisolid form. The embodiments herein are provided to treat or manage the fecal sludge in low cost using less resources. Description of the Related Art

Excreta is a part of everyday life. The negative part of all the excreta is that if it is not managed properly, these waste products cause waterborne diseases and water pollution. And a lack of access to clean, functioning toilets threatens human dignity. However, that is the case for 2.4 billion people worldwide without access to adequate sanitation. In many developing countries, fecal sludge is not properly managed. This may be due to a lack of mandated institutions and little awareness of the impact of poor sanitation; the lack of technical expertise and experience; inability to source funds for to purchase of vacuum trucks and treatment, or lack of knowledge required to be initiate and implement successful FSM programs. This can result in the poor performance of onsite sanitation facilities (OSSFs), septic tank and pit latrine overflows, unsafe emptying of pit latrines, and the dumping of untreated pathogenic fecal sludge into the environment.

Fecal sludge is in a slurry or semisolid form, and results from the collection, storage or treatment of combinations of excreta and black water (i.e. toilet wastewater) from onsite sanitation technologies. Fecal sludge needs to be safely contained onsite, and then the accumulated fecal sludge needs to be safely emptied, transported to a treatment plant, treated, and used for resource recovery or disposed of safely. However, most fecal sludge is not properly managed with a lack of sanitary emptying, no treatment plants, and illegal dumping directly in the environment.

Now to treat fecal sludge in a low cost is a challenge and generally sewerage sludge is discharged into water bodies like ocean or river, etc. which affects aquatic environment and also pollutes ground water. Many a times fecal sludge is directly dumped into large pits located outside of the main city which becomes breeding ground for many organisms leading to the diseases like cholera, typhoid, hepatitis, trachoma ringworm, etc. Thus, there is a need to provide an improved an integrated low-cost fecal sludge treatment solution which degrades the sludge into water. This water may be useful for irrigation, landscaping, propagation of wildlife and fisheries, industrial use, etc. The solution should also be capable of generating lesser sludge compared to other fecal sludge treatment plants.

SUMMARY

The embodiment herein provides a process for treatment of fecal sludge. The process includes steps of inletting semi-solid fecal sludge from a sludge carrying tanker or through any inlet pipe, screening the incoming sludge in a gritt screening chamber to settle the sludge having particle size greater than 10mm, degrading the sludge in anaerobic condition for a period between 48 to 96 hours in a biological digester, passing the sludge through an anoxy chamber to reduce nitrogen content in the sludge thereby further degrading the sludge, sending the degraded sludge in a primary lamella clarifier which includes an oil and grease separator, wherein the separator through a gravity action separates oil and grease from the sludge to obtain more liquid form of the sludge, passing the liquid form of the sludge through an aeration chamber 1 to dose off 50 to 80% air, thereby decreasing biochemical oxygen demand (BOD) and chemical oxygen demand COD of the liquid, passing the liquid form of the sludge through an aeration chamber 2 to dose off 50 to 80% air, thereby further decreasing BOD and COD of the liquid, flocculating the liquid sludge with an electro flocculation or chemical flocculation process in the aeration chamber 2 to make suspended solid floe spontaneously, passing the flocculated liquid through a secondary lamella to obtain a treated liquid, wherein the settleable solids drains to a sludge drawing bed and remaining water to the biological digester, collecting the treated liquid in a holding sump, wherein the liquid is ozonized for disinfection, passing the treated liquid through a calcium carbonate sand filter to maintain the PH value of the liquid, passing the treated liquid through an activated carbon filter which absorbs the odors and other absorbable impurities from the liquid, and filtering the treated liquid further with a 5 micron filter to remove the impurities lager than 5 micron and obtain a treated liquid acceptable for industrial consumption.

In one embodiment, the PH standard may be controlled through the calcium carbonate filter.

A fecal sludge treatment plant includes an inlet pipe through which a semi-solid fecal sludge is received in the plant, a gritt screening chamber to screen the incoming sludge, wherein the chamber facilitates to settle the sludge having particle size greater than 10mm, a biological digester for degrading the sludge in anaerobic condition for a period between 48 to 96 hours, an anoxy chamber to reduce nitrogen content in the sludge thereby further degrading the sludge, a primary lamella clarifier which includes an oil and grease separator, wherein the separator through a gravity action separates oil and grease from the sludge to obtain more liquid form of the sludge, an aeration chamber 1 to dose off 50 to 80% air, thereby decreasing biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the liquid, an aeration chamber 2 to dose off 50 to 80% air, thereby further decreasing BOD and COD of the liquid, a secondary lamella to obtain a treated liquid, wherein the settleable solids drains to a sludge drawing bed and remaining water to the biological digester, a holding sump wherein the liquid is ozonized for disinfection, a calcium carbonate sand filter to maintain the PH value of the liquid, an activated carbon filter which absorbs the odors and other absorbable impurities from the liquid, and a 5 micron filter to remove the impurities lager than 5 micron and obtain a treated liquid acceptable for industrial consumption.

These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments:

The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:

FIG. 1 illustrates a fecal sludge treatment plant to treat sludge which is in a slurry or semisolid form according to an embodiment mentioned herein; and

FIG. 2 and FIG. 3 is a process illustrating treatment of a fecal sludge inside a fecal sludge treatment plant according to an embodiment mentioned herein. Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.

Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.

References in the specification to“one embodiment” or“an embodiment” member that a particular feature, structure, characteristics, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase“in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. That is, those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail. All statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. Thus, for example, it will be appreciated by those skilled in the art that block diagrams herein can represent conceptual views of illustrative circuitry embodying the principles of the technology. Similarly, it will be appreciated that any flow charts, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether such computer or processor is explicitly shown.

Accordingly, there remains a need to provide an improved and integrated low-cost fecal sludge treatment solution which degrades the sludge into water. This water may be useful for irrigation, landscaping, propagation of wildlife and fisheries, industrial use, etc. The solution should also be capable of generating lesser sludge compared to other fecal sludge treatment plants.

The present embodiments herein provide an integrated low-cost fecal sludge treatment plant which degrades the sludge into water. The water then may be useful for irrigation, landscaping, propagation of wildlife and fisheries, industrial use, etc. The pant of the present embodiment also generates less sludge as compared to other fecal sludge treatment plants. The sludge generated may be used as manure. The plant of the present embodiment requires less space, has a very low maintenance cost, consumes less electricity and eliminate odour after first stage treatment. Referring now to the figures, more particularly from FIG. 1 and FIG. 2, where similar reference characters denote corresponding features consistently throughout the figures, preferred embodiments are shown. FIG. 1 illustrates a fecal sludge treatment plant to treat the sludge which is in a slurry or semisolid form according to an embodiment mentioned herein. The fecal sludge treatment plant includes a sludge inlet 102, a gritt screening chamber 104, a biodigester 106, an anoxy chamber 108, a primary lamella clarifier 110, an aeration tank 1 112, an aeration tank 2 114, an electro-flocculation or chemical flocculation chamber 114, a secondary lamella 116, a holding sump 118, a pressure sand filter 120, an activated carbon filter 122, a 5 -micron water filter 124 and a treated water outlet.

The sludge may be introduced in the plant through the sludge inlet 102. In one embodiment the sludge may be directly introduced in the plant through a sludge carrying tanker. In an embodiment, the gritt chamber 104 screens the incoming sludge which facilitates to settle the sludge having particle size greater than 10mm. the biological digester 106 degrades the sludge in anaerobic condition for a period between 48 to 96 hours.

In an embodiment, the anoxy chamber 108 may reduce nitrogen content in the sludge thereby further degrading the sludge. The primary lamella clarifier 110 may include an oil and grease separator. The separator through a gravity action separates oil and grease from the sludge to obtain more liquid form of the sludge. In an embodiment, the primary lamella clarifier 110 resends the settleable solids to the biodigester 106 to make them repeat the whole process again which results in less sludge generation.

In an embodiment, the aeration chamber 1 112 doses off 50 to 80% air, thereby decreasing biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the liquid. There is one more aeration chamber 2 114 to further dose off 50 to 80% air, thereby further decreasing BOD and COD of the liquid. The secondary lamella 116 obtains a treated liquid, wherein the settleable solids drains to a sludge drawing bed and remaining water to the biological digester 106.

In a holding sump 118 the liquid may be ozonized for disinfection. The calcium carbonate pressure sand filter 120 to maintain the PH value of the liquid. The activated carbon filter 122 absorbs the odors and other absorbable impurities from the liquid. The 5 micron filter 124 is placed to remove the impurities lager than 5 micron and to obtain a treated liquid acceptable for industrial consumption.

FIG. 2 and FIG. 3 illustrates the process of treatment of the fecal sludge inside a fecal sludge treatment plant 100 according to an embodiment mentioned herein. In step 202, the fecal sludge may be introduced in the fecal treatment plant through the sludge inlet 102. In step 204, the sludge may be screened through the gritt screening chamber 104, where the settleable solid settles at the bottom of the chamber and above 10mm particles are screened in the process. In step 206, the screened particles may be then passed through the biodigester 106 which degrades the sludge by anaerobic condition retention period of 48 to 96 hours. Then in step 208, the sludge from the biodigester may be passed through the anoxy chamber 108 to reduce the nitrogen and make it ready for aerobic treatment. In step 210, for the aerobic treatment the sludge may be passed through the primary lamella clarifier 110. The lamella clarifier with oil and grease separator, where the settleable solids settles down in the bottom of the lamella clarifier and then again moved to bio digester with oil and grease. Here the odour may also be eliminated in the first stage itself. In step 212, the sludge is passed through the aeration tank 1 , where 50 to 80% of volume of air is dosed off by air diffuser to decrease BOD and COD of the semi-liquid sludge. Here the detention time may be two hours. In step 212, the sludge may be passed through the aeration tank 2 to decrease BOD and COD where 50 to 80% of volume of air is dosed by air diffuser. In step 216, the sludge may be passed through the electro-flocculation or chemical flocculation chamber to make the suspended solids float spontaneously.

In step 302, the sludge may be passed through the secondary lamella 116, where the settleable solids drain to sludge drawing bed and the remaining water drain to the bio- digester. In step 304, the treated water may be collected and ozonized for disinfection in the holding sump 118.

In step 306, the treated water passes through the calcium carbonate-based pressure sand filter 120 which enables the treated water to maintain PH value. Further in step 308, the treated water may be passed through the activated carbon filter 122 which absorbs odors and other absorbable impurities. In the last stage i.e. step 310, the 5- micron water filter 124 restricts the rest of the impurities larger than 5 microns. The treated water is then taken out from the treated water outlet. This treated water may now be useful for irrigation, landscaping, propagation of wildlife and fisheries, industrial use, etc.

The advantageous embodiment of the present disclosure is to provide no odour after first stage of clarification. Here the PH standards are controlled through the calcium carbonate filter. The plant as disclosed in the present embodiment provides anaerobic process, aerobic process, electro-flocculation or chemical flocculation, ozonation of water and tertiary treatment of water through absorption by the carbon and calcium carbonate sand filtering process. In another advantageous embodiment of the present disclosure, the objective is to provide a machine which is very easy to handle, less sludge generation therefore less carbon footprints and one person is enough to operate the whole system. The plant of the present embodiment requires very less space and land, is very low in maintenance cost, uses very less electricity and eliminates odour in the first stage of treatment. Thus, the plant as disclosed in the present embodiment, provide an improved and integrated low-cost fecal sludge treatment solution which degrades the sludge into water. This water may then be put to use for irrigation, landscaping, propagation of wildlife and fisheries, industrial use, etc. The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method or alternate methods. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the subject matter described herein.

The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the discussion herein, it is appreciated that throughout the description, discussions utilizing terms such as“generating” or“monitoring” or“displaying” or“tracking” or “identifying”“or receiving” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope.

Claims

CLAIMS I CLAIM:

1. Process for treatment of fecal sludge said process comprising steps of:

inletting semi-solid fecal sludge from a sludge carrying tanker (102) or through any inlet pipe;

screening the incoming sludge in a gritt screening chamber (104) to settle the sludge having particle size greater than 10mm;

degrading the sludge in anerobic condition for a period between 48 to 96 hours in a biological digester (106);

passing the sludge through an anoxy chamber (108) to reduce nitrogen content in the sludge thereby further degrading the sludge;

sending the degraded sludge in a primary lamella clarifier (110) which includes an oil and grease separator, wherein the separator through a gravity action separates oil and grease from the sludge to obtain more liquid form of the sludge;

passing the liquid form of the sludge through an aeration chamber 1 (112) to dose off 50 to 80% air, thereby decreasing biochemical oxygen demand (BOD) and chemical oxygen demand COD of the liquid;

passing the liquid form of the sludge through an aeration chamber 2 (114) to dose off 50 to 80% air, thereby further decreasing BOD and COD of the liquid;

flocculating the liquid sludge with an electro flocculation or chemical flocculation process in the aeration chamber 2 to make suspended solid floe spontaneously;

passing the flocculated liquid through a secondary lamella (116) to obtain a treated liquid, wherein the settleable solids drains to a sludge drawing bed and remaining water to the biological digester (106); collecting the treated liquid in a holding sump (118), wherein the liquid is ozonized for disinfection;

passing the treated liquid through a calcium carbonate sand filter (120) to maintain the PH value of the liquid;

passing the treated liquid through an activated carbon filter (122) which absorbs the odors and other absorbable impurities from the liquid; and

filtering the treated liquid further with a 5 micron filter (124) to remove the impurities lager than 5 micron to obtain a treated liquid which is taken out from a treated water outlet for industrial consumption.

2. The process as claimed in claiml, wherein the PH standard is controlled through the calcium carbonate filter (120).

3. A fecal sludge treatment plant (100) comprising:

an inlet pipe (102) through which a semi-solid fecal sludge is received in the plant;

a gritt screening chamber (104) to screen the incoming sludge, wherein the chamber facilitates to settle the sludge having particle size greater than 10mm;

a biological digester (106) for degrading the sludge in anaerobic condition for a period between 48 to 96 hours;

an anoxy chamber (108) to reduce nitrogen content in the sludge thereby further degrading the sludge;

a primary lamella clarifier (110) which includes an oil and grease separator, wherein the separator through a gravity action separates oil and grease from the sludge to obtain more liquid form of the sludge;

an aeration chamber 1 (112) to dose off 50 to 80% air, thereby decreasing biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the liquid; an aeration chamber 2 (114) to dose off 50 to 80% air, thereby further decreasing BOD and COD of the liquid;

a secondary lamella (116) to obtain a treated liquid, wherein the settleable solids drains to a sludge drawing bed and remaining water to the biological digester (106);

a holding sump (118), wherein the liquid is ozonized for disinfection; a calcium carbonate pressure sand filter (120) to maintain the PH value of the liquid;

an activated carbon filter (122) which absorbs the odors and other absorbable impurities from the liquid; and

a 5 micron filter (124) to remove the impurities lager than 5 micron and to obtain a treated liquid which is taken out from a treated water outlet for industrial consumption.

4. The fecal sludge treatment plant as claimed in claim 3, wherein the liquid sludge is flocculated with an electro flocculation or chemical flocculation process in the aeration chamber 2 to make suspended solid floe spontaneously.

5. The fecal sludge treatment plant as claimed in claim 3, wherein the PH standard is controlled through the calcium carbonate filter (120).