Description:The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

Moreover, all statements herein reciting 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).
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations.

The consortium of microorganism is supplied by DRDO, Government of India, New Delhi.
One embodiment of the invention to provide a Grit filter which uses a novel up flow filtration, the grid falling down due to gravity with a self-cleaning Process to efficiently remove larger non biodegradable and debris from wastewater. Filter element can be easily accessed and replaced. The size of the openings in the grid is 2mm which enable it to effectively capture larger objects and debris from wastewater, including a wide range of non-biodegradable solids such as trash, hair, lint, kitchen waste, grit, and plastics. The filter is equipped with a sophisticated self-cleaning system that leverages a precisely calibrated nozzle spray of water in order to maintain optimal performance and prevent clogging. This targeted cleaning mechanism efficiently removes captured debris, ensuring the filter's continued effectiveness and minimizing maintenance requirements. The grit filter provides a reliable and efficient solution for wastewater treatment applications, ultimately contributing to improved system performance.

Another embodiment of the invention to provide a Hydrodynamic Cavitation unit to treat sewage water to aid digestion of fecal matter at ease. Hydrodynamic cavitation process is a key component of the sewage treatment process, utilizing the principles of cavitation to enhance wastewater treatment, involves creating rapid pressure changes in the wastewater that lead to the formation and collapse of vapor bubbles. This process can significantly enhance the waste water's characteristics before it enters the anaerobic bio-digester. Hydrodynamic cavitation is the rapid formation and collapse of vapor bubbles within a liquid, caused by pressure variations due to fluid flow through constrictions or around obstacles, leading to intense pressure and temperature changes. Nano particles are formed when a liquid flows through a narrow passage or around an obstacle, the local pressure decreases as the flow velocity increases. Bubbles formed when the local pressure drops below the liquid's vapor pressure, the liquid starts to vaporize, forming small bubbles. As the liquid flows further and the pressure increases, the bubbles rapidly collapse, generating intense pressure and temperature spikes, as well as shock waves. Cavitation disrupts larger organic particles, breaking them into smaller pieces. This process increases the surface area available for microbial activity inside the ABD, facilitating more efficient digestion. By reducing particle size, cavitation ensures that the microorganisms in the ABD have quicker and easier access to organic matter for degradation. The retention time decreased when the size of the particulate matter in water in the ABD tank. The mechanical forces generated by cavitation (shear forces, micro-jetting, and turbulence) promote better mixing, which leads to more uniform distribution of organic material. This enhanced mixing helps the microorganisms in the ABD to more effectively digest organic compounds. Cavitation stimulate microbial growth and activity, boosting the overall efficiency of the anaerobic digestion process. This results in a faster breakdown of complex organic matter into biogas, reducing the retention time needed for digestion. Since organic matter is already pre-treated by cavitation, the anaerobic digester requires less time to break down the material further. This effectively shortens the hydraulic retention time (HRT) of the ABD, allowing for a higher throughput of wastewater while still maintaining effective digestion.

Yet another embodiment of the invention, an Anaerobic Digestion Tank (ABD) and leverages anaerobic digestion, a process that offers significant advantages, including no energy requirements. However, anaerobic digestion is inherently a slow process, necessitating larger tank sizes and longer retention times, typically ranging from 2.5 to 4 days. This prolonged retention period can lead to increased capital costs and larger size treatment plant footprints. In the present invention small tanks were used as it is integrated with hydrodynamic cavitation system which creating cavitation bubbles that implode, generating intense localized forces. These forces increase the surface area of contaminants, providing more sites for bacteria to act upon and accelerating the digestion process. The benefits of incorporating a hydrodynamic cavitation system are multifaceted. Firstly, it improves the efficiency of anaerobic digestion, allowing for more effective breakdown of organic matter. Secondly, it reduces the retention time required for treatment, which can lead to smaller tank sizes and lower capital costs. Finally, by optimizing the digestion process, the hydrodynamic cavitation system can help reduce the overall footprint of the treatment plant, making it a more compact and efficient solution.
The Anaerobic Bacterial Digestion (ABD) tank is a vital component of the sewage treatment process. This stage harnesses the power of anaerobic microorganisms to break down organic matter in sewage water, leveraging their metabolic processes to degrade complex pollutants.
In the ABD tank is configured to perform the following function:
Maintains anaerobic conditions inside the tank for anaerobic bacteria survival.
a) Digests and produces methene gas and gives escape route
b) Multiplies huge amount bacteria aiding continuous digestion
c) Reduces COD significantly below 350 mg/l
Sewage water pre-treated by hydrodynamic cavitation undergoes intensive biological treatment. A diverse consortium of anaerobic bacteria thrives in this environment, degrading organic pollutants into simpler, more manageable forms. This process is specifically designed to operate without sludge production, ensuring efficient wastewater treatment, minimizing environmental impact, and reducing operational costs.
The breakdown of particles during the cavitation process increases the surface area available for microbial colonization, further accelerating digestion. With improved mixing, microbial activity, and particle breakdown, the ABD operates more efficiently. The reduction in retention allows for a more compact digester system, which can handle larger volumes of wastewater without compromising on performance. The ABD tank is adapted to eliminate sludge production, reducing waste disposal challenges and environmental footprint.
The ABD tank is constructed from reinforced cement concrete and consists of three interconnected compartments, carefully sized to optimize digestion efficiency. The compartment capacity ratio is 40:30:30, ensuring a seamless progression of treatment stages. Pre-treated Fecal sludge enters the first compartment (40% capacity) through an inlet, initiating anaerobic digestion. Microorganisms break down complex organic matter, producing biogas and partially treated sludge. The partially treated sludge then flows into the second compartment (30% capacity) through inter-compartmental flow passage, where further digestion occurs, refining the treatment process. Finally, the treated water enters the third compartment (30% capacity) through inter-compartmental flow passage, where final treatment take place, ensuring high-quality effluent.
All chambers are closed to maintain anaerobic conditions, and strategically placed pipes facilitate smooth flow and transfer between compartments. The inlet pipe introduces raw sludge, while three rising pipes regulate inter-compartment flow and ultimately direct treated water to the outlet.
Anaerobic Microbial Innoculum : Microbial Consortium developed is a mixture of different types of bacteria (Hydrolytic,Acidogenic,Acetogenic and methanogenic Groups ) responsible for breakdown of complex polymers into simple sugars which are further broken down into low chain fatty acids. The microbial consortium was developed by enriching desired group of bacteria from mixture of microbes by natural selection. The efficiency of the consortium was improved by fortification of several critical species of bacteria. The consortium was also augmented with Volatile Fatty acids Degrade. The microbial Consortium has been gradually adapted to grow even at 5°C so that it can work efficiently at Mesophilic as well as Psychrophilic Temperature. Microbial Consortium efficiently degrades human waste at temperature as low as 5°C and as high as 50°C.
Working Principle of Anaerobic Bacteria Digester
The anaerobic bio degradation process is mediated by four sequential steps namely hydrolysis, acidogenesis, acetogenesis and methanogenesis with last two being poorly understood and very sensitive at low temperatures. Low temperature operations need low temperature active bacterial inoculum for efficient bio degradation.
The anaerobic degradation of organic substances takes place in several steps comprising of hydrolysis, acidification, acetogenesis and methanogenesis, which are dependent on each other for food and energy requirement. Each step is performed by specific class of microorganisms. Undissolved organic substances are broken down by hydrolytic bacteria (cellulolytic - Acetivibrio, Ruminococcus, amylolytic - Butyrivibrio, Bacteroides, proteolytic - Butyrivibrio, Selenomonas) with the help of exoenzymes. Proteins, carbohydrates and fats are converted into amino acids, monosaccharides, fatty acids and glycerol. Fermentative bacteria (Acetobacter woodii, Clostridium aceticum, Clostridium autotrophicum) convert monosaccharides into low chain fatty acids, alcohols, CO₂ and hydrogen Glycerol is converted into pyruvate and fatty acids chains are degraded to acetic acid by ẞ-oxidation reaction process. Certain groups of bacteria degrade amino acids by coupled oxidation-reduction reactions (Stickland reaction). In acetogenic phase (Syntrophobacter wolinii, Syntrophomonas wolfei, Clostridium formicoaceticum), alcohol and higher chain fatty acids are built to acetate, hydrogen and CO2, which are the main substrates for methanogens (Methanosaeta concilii, Methanobacterium bryantii, Methanococcus jannaschii, Methanosarcina barkeri, Methanothrix soehngenii). For thermodyanamic reasons the conversion of ethanol, propionate, and butyrate into acetate by the acetogens is feasible if hydrogen produced is consumed at the place of origin by methanogenic or sulphate reducing bacteria (SRB). Thus close association of acetogens and methanogens/SRBs is essential. Methanogens have a narrow substrate spectrum and are sensitive to oxygen. All the methanogens can process hydrogen, some of them formate and other methanol, methyl amine and acetate.
Acetate, propionate, butyrate was identified as important VFA intermediates during degradation of night soil. Butyrate is degraded preferentially over the propionate. Dilution of microbial population lead to accumulation of acetate and hydrogen indicating the requirement of high density of hydrogen and acetate utilizing methanogens for low temperature methanogenesis from propionate and butyrate. An aggregation of proton reducing acetogenic bacteria and methanogens accelerates the process.
Temperature may affect not only the rate of biomethanation but also the pathway of methane production by changing the activity and abundance of individual microorganisms. In anaerobic degradation, hydrolysis and methanogenesis are the rate limiting steps. But in low temperature (<10°C), hydrolysis is commonly found to be the rate limiting step in anaerobic degradation and as temperature decreases, the rate of hydrolysis become even lower. At such temperatures, acetate formation and acetoclastic methanogenesis is the main pathway for methane formation. However, at further low temperatures (<5 °C) acetoclastic methanogenesis has been found to be rate limiting for methane production at high acetate concentration
Anaerobic degradation of organic polymers
The anaerobic degradation pathway of organic matter is a multi step process of series and parallel reactions. This process of organic matter degradation proceeds in four successive stages, namely: (i) hydrolysis, (ii) acidogenesis, (iii) acetogenesis, and (iv) methanogenesis. These are discussed below.
Methanogenic bacteria are located at the end of the anaerobic food chain and, partly thanks to their activity, no large quantities of organic matter accumulate in anaerobic environments, where this matter is inaccessible to aerobic organisms. The anaerobic digestion process involves a complex food web, in which organic matter is sequentially degraded by a wide variety of micro-organisms. The microbial consortia involved jointly convert complex organic matter and ultimately mineralize it into methane (CH4), carbon dioxide CO2, ammonium (NH3), hydrogen sulphide (H2S) and water (H2O).
The anaerobic ecosystem is the result of complex interactions among microorganisms of several different species. The major groupings of bacteria and reaction they mediate are: (i) fermentative bacteria, (ii) hydrogen-producing acetogenic bacteria, (iii) hydrogen- consuming acetogenic bacteria, (iv) carbon dioxide- reducing methanogens, and (v) aceticlastic methanogens. The reactions they mediate are presented
Reactive scheme for the anaerobic digestion of polymeric materials. Numbers indicate the bacterial groups involved: 1. Hydrolytic and fermentative bacteria, 2. Acetogenic bacteria, 3. Homo-acetogenic bacteria, 4. Hydrogenotrophic methanogens, 5. Aceticlastic methanogens.
Hydrolysis, where enzymes excreted by fermentative bacteria (so-called ‘exo-enzymes’) convert complex, undissolved material into less complex, dissolved compounds which can pass through the cell walls and membranes of the fermentative bacteria.
Acidogenesis, where the dissolved compounds present in cells of fermentative bacteria are converted into a number of simple compounds which are then excreted. The compounds produced during this phase include volatile fatty acids (VFAs), alcohols, lactic acid, CO2, H2, NH3 and H2S, as well as new cell material.
Acetogenesis (intermediary acid production) where digestion products are converted into acetate, hydrogen (H2) and CO2, as well as new cell material.
Methanogenesis, where acetate, hydrogen plus carbonate, formate or methanol are converted into methane, CO2 and new cell material.
In this global scheme, the following sub-processes can be distinguished:
1) Hydrolysis of biopolymers:
- hydrolysis of proteins
- hydrolysis of polysaccharides
- hydrolysis of fats
2) Acidogenesis/fermentation:
- anaerobic oxidation of amino acids and sugars
- anaerobic oxidation of higher fatty acids and alcohols
3) Acetogenesis:
- formation of acetic acid and H2 from intermediary products (particularly VFAs)
- Homo acetogenesis: the formation of acetic acid from H2 and CO2
4) Methanogenesis:
- methane formation from acetic acid
- methane formation from hydrogen and carbon dioxide

The tertiary treatment stage is a crucial step in enhancing the quality of treated water. Traditional systems often rely on Pressure Sand Filters (PSF) and Activated Carbon Filters (ACF), which have significant limitations. These filters require regular media replacement, which can be costly and time-consuming. Additionally, they are prone to clogging over time, leading to reduced efficiency and increased maintenance needs.

Another embodiment of the invention to provide a filtering system having 500-micron mesh eliminating the need for frequent media replacements and minimizing the risk of clogging. By providing reliable and efficient filtration solution, present system ensures that treated water meets stringent quality standards. This filter ensures thorough treatment and minimizing waste.

Further embodiment of the invention for enhancing the treated water quality, the Advanced Oxidation Process (AOP), which utilizes ozone to disinfect and get rid of harmful pathogens. To maximize the effectiveness of AOP, the system integrates a Nano Bubble Generator with Ozone generator system. This technology produces extremely fine bubbles that increase the surface area helping ozone to react more efficiently with pollutants. The result is the best treated water for all use other than drinking.

The Nano Bubble Ozone Generator generates ozone nano bubbles, which are then utilized for advanced oxidation, providing a highly effective disinfection and pollutant degradation solution. Ozone is a strong oxidizer and can effectively break down organic pollutants that are not fully degraded during the anaerobic digestion process. It generates hydroxyl radicals (•OH), which are extremely reactive and can degrade a wide range of organic contaminants. In the AOP, ozone is especially effective at treating micro pollutants like pharmaceuticals, pesticides, and endocrine-disrupting chemicals that may be present in the wastewater after anaerobic digestion. Ozone break down complex organics, reducing the Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) of the treated water. Ozone is also a strong disinfectant. It inactivate bacteria, viruses, and other pathogens present in the treated wastewater, ensuring that the effluent is safe for discharge or reuse. This is particularly important if the treated water is intended for non-potable reuse or irrigation. The combination of cavitation pre-treatment, anaerobic digestion, and AOP with ozone results in a treated effluent that meets stringent water quality standards. This ensures that the wastewater is either safe for discharge into natural water bodies or suitable for reuse in various application,

Figure 1 illustrate a system for treating waste water comprising; waste water inlet (1) configured to feed the waste water into the receiving tank (2); an outlet release the waste into grit filter (3) from the receiving tank (2) adapted to remove large and heavier particles and store the waste water in storage tank I (4); the pump (5) transports the wastewater to a Hydrodynamic Cavitation unit (6), which is configured to generate high shear forces and turbulence within the wastewater, thereby facilitating the breakdown of pollutants into smaller particles, the resulting Pre- treated wastewater is subsequently conveyed to storage tank II (7); the anaerobic bacterial digester (8) is configured to digest the particulate matter present in the wastewater and to feed the resulting effluent into a filtering system (9) is configured to remove suspended solids and particulate matter from the effluent, thereby producing a clarified effluent water; the Advanced Oxidation Process (AOP) Tank (10) is configured to degrade remaining toxins, color, and odor from the clarified effluent, producing treated water, which exits the system and is suitable for non-potable applications such as flushing, irrigation, and industrial use.
A method for treating wastewater using the system of the invention comprising; introducing waste water through an inlet (1) into the receiving tank (2); releasing the waste water into grit filter through Pump (3) from the receiving tank (2) adapted to remove large and heavier particles and store the waste water in storage tank I (4); transporting the wastewater to a Hydrodynamic Cavitation unit (6), which is configured to generate high shear forces and turbulence within the wastewater, thereby facilitating the breakdown of pollutants into smaller particles, the resulting Pre-treated wastewater is subsequently conveyed to storage tank II (7); digesting the particulate matter present in the wastewater in an anaerobic bacterial digester (8) with consortium of bacteria; feeding the digested effluent into a filtering system (9) is configured to remove suspended solids and particulate matter from the effluent, thereby producing a clarified effluent water; treating the wastewater in the Advanced Oxidation Process (AOP) Tank (10) to degrade remaining toxins, colour, and Odor from the clarified effluent, producing treated water, which exits the system and is suitable for non-potable applications such as flushing, irrigation, and industrial use.
Figure 2 illustrates the grit filter (3) is configured to eliminate coarse solids and sediments from the incoming wastewater supplied via the inlet (1) comprises a the concrete tank (11) has a closed bottom and a removable top cover (14), facilitating access for maintenance and inspection; an inlet cylindrical member (12) provided on the top cover (14) and extends downwardly along the inner wall of the tank and terminates below a grid sheet member (13) positioned within the tank to facilitate the settling of grit and heavy particles; a grid sheet member (13) is positioned internally at a mid-level within the concrete tank (11) and is configured to trap and facilitate the settling of grit and other heavy particles at the bottom of the tank which is supported by grid support bars (15) that are fixed to the removable top cover (14), thereby ensuring stable positioning and facilitating ease of maintenance; the tank is sealed with a top cover to prevent external contamination and to control odor emissions; an air vent (16) is provided on the top cover (14) and is configured to release gases generated during the settling process, thereby maintaining internal pressure balance and ensuring operational safety; an outlet cylindrical member (17) is provided at an upper side portion of the tank (11), above the grid sheet member (13), and is configured to allow treated water to exit the tank and the said outlet is positioned above the sedimentation level to prevent the discharge of settled solids; a manually operated ball valve (18) is installed at the bottom outlet pipe of the tank (19), and is configured to enable controlled discharge of the accumulated grit and settled solids.
Figure 3 illustrates the Hydrodynamic Cavitation unit (6) is configured to induce high-intensity turbulence and cavitation in the flowing wastewater to facilitate the breakdown of pollutants said unit comprises a hollow cylindrical body having an inlet (21) at a first end and an outlet (23) at a second end; a constricted orifice (22) disposed within the hollow cylindrical body; wherein the wastewater is introduced into the unit through the inlet and is directed at high velocity through the orifice, thereby undergoing a rapid pressure drop that induces the formation of vapor cavities or microbubbles; the vapor cavities or microbubbles collapse in a downstream region of elevated pressure, releasing localized energy in the form of shear forces and shockwaves; wherein the released energy facilitates the disruption of organic and inorganic pollutants present in the wastewater, enhancing their biodegradability; and the treated wastewater, comprising finely dispersed contaminants, exits the unit through the outlet.
A method for treating wastewater using the system of the invention wherein hydrodynamic cavitation comprising the steps of: introducing wastewater into a hollow cylindrical unit through an inlet; forcing the wastewater at high velocity through a narrow orifice disposed within the cylindrical unit; inducing a pressure drop across the orifice, resulting in the formation of vapor cavities or microbubbles; collapsing the vapor cavities in a downstream region of higher pressure, thereby releasing localized energy in the form of shear forces and shockwaves; disrupting organic and inorganic pollutants via said shear forces and shockwaves to enhance their biodegradability; and discharging the processed wastewater containing finely broken down contaminants through an outlet.
Figure 4 illustrates a rotary screening unit for preliminary Non-biodegradable solid-liquid separation in a wastewater treatment system, comprising; a cylindrical outer casing (17) having a closed end and a removably closable opposite end; a perforated circular grid sheet (3) concentrically positioned beneath the cylindrical outer casing and configured as a primary filtration medium for capturing coarse solids, suspended matter, and floating debris, while allowing pre-filtered liquid to pass through; an inlet to introduce wastewater and an outlet positioned to receive the filtered liquid discharged through the perforations of the grid sheet for subsequent purification stages; the cylindrical outer casing (17) comprising a longitudinally extending inner tapered surface forming a concentric ring; a shaft having a complementary tapered outer surface, the shaft being configured to interface with the tapered inner surface of the casing to enable stable rotation and alignment of internal components; and a structural support frame (20) configured to provide mechanical stability and maintain proper alignment of the screening unit during operation.
A method for treating wastewater using the system wherein a rotary screening unit comprising: introducing incoming wastewater into a cylindrical outer casing having a closed end and a removably closable opposite end; directing the wastewater onto a perforated circular grid sheet concentrically positioned within the unit, the grid sheet configured to trap coarse solids, suspended matter, and floating debris; rotating the cylindrical outer casing about a shaft having a tapered outer surface interfacing with a correspondingly tapered inner surface of the casing to ensure concentric alignment and stable rotation; allowing the filtered liquid to pass through the perforations of the grid sheet into a surrounding collection space; discharging the pre-filtered wastewater through an outlet for further purification; and supporting the screening unit on a structural frame to maintain mechanical stability and alignment during operation.
Figure 5 illustrates an anaerobic bacterial digester (27) for treating wastewater, comprising: a housing defining at least three sequentially connected compartments, including a first compartment (28), an intermediate compartment (29 & 30), and a final compartment (31); an inlet provided near a top side wall of the housing and configured to introduce wastewater containing fecal and organic matter into the first compartment (28); a consortium of anaerobic bacteria disposed within the first compartment (28) and configured to initiate degradation of the fecal and organic matter; an immobilization matrix disposed within the first compartment (28) and configured to support bacterial colonization and enhance microbial activity; a first inter-compartmental flow passage provided at an upper end portion of a side wall between the first compartment (28) and the intermediate compartment (29); a second inter-compartmental (30) flow passage provided at a upper end portion of a side wall between the intermediate compartment (30) and the final compartment (31), wherein the first and second flow passages are configured to facilitate progressive transfer of wastewater through the compartments; and an outlet provided at a top end portion of the final compartment (31), configured to discharge treated wastewater having significantly reduced biological oxygen demand (BOD) and chemical oxygen demand (COD), suitable for subsequent treatment. The anaerobic bacterial digester (27) comprising the first compartment (28) having consortium of anaerobic bacteria to disintegrate faecal and organic matter and an immobilization matrix supports bacterial colonization; second compartment comprising digestion and disintegration of organic matter continue where the rising and falling pipes provided to facilitate water flow and further treatment and third compartment configured to makes final adjustments to the biological and chemical oxygen demand (BOD and COD), significantly lowering these levels before the water exits the tank.
An anaerobic bacterial digester (8) comprising of three interconnected compartments capacity ratio is 40:30:30; the HC treated feacal sludge enters the first compartment (40% capacity) through a falling pipe, initiating anaerobic digestion thereby microorganisms break down complex organic matter, producing biogas and partially treated sludge; the partially treated sludge then flows into the second compartment (30% capacity) via a rising pipe, where further digestion occurs, refining the treatment process; the treated water enters the third compartment (30% capacity) through another rising pipe, where final treatment take place, ensuring high-quality effluent.
A method for treating wastewater using the system wherein anaerobically treating wastewater using a multi-compartment digester comprising: introducing wastewater containing fecal and organic matter into a first compartment of an anaerobic bacterial digester through an inlet located near a top side wall of the digester; initiating anaerobic degradation of the fecal and organic matter in the first compartment by means of a consortium of anaerobic bacteria; providing an immobilization matrix within the first compartment to support bacterial colonization and enhance microbial activity; progressively transferring the partially treated wastewater from the first compartment to an intermediate compartment through a flow passage located at an upper end portion of a side wall; further transferring the wastewater from the intermediate compartment to a final compartment through a flow passage located at a upper end portion of a side wall; and discharging treated wastewater from the final compartment through an outlet located at a top end portion of the compartment, wherein the treated wastewater has significantly reduced biological oxygen demand (BOD) and chemical oxygen demand (COD), rendering it suitable for subsequent treatment.
Figure 6 illustrates the Advanced Oxidation Process (AOP) system (10) for treating wastewater using ozone and nano-bubble technology (28), the system comprising; an oxygen concentrator configured to draw atmospheric air and produce a concentrated oxygen stream containing approximately 92% oxygen;
an ozone generator configured to receive the concentrated oxygen stream and generate ozone gas therefrom; a venturi ejector (29) configured to receive wastewater and mix it with the ozone gas supplied from the ozone generator, thereby initiating oxidation; a pressure adjuster valve (30) operatively connected to the ozone gas line and configured to regulate the flow rate and pressure of ozone entering the venturi ejector (29) to ensure efficient mixing; a nano-bubble generator configured to produce fine ozone-containing nano-bubbles, thereby enhancing the oxidation efficiency by increasing the contact surface area between ozone and pollutants; a static mixer (27) disposed downstream of the nano-bubble generator and configured to further blend the mixture for uniform ozone distribution; an AOP tank configured to receive the mixed fluid and facilitate ongoing oxidation reactions for degrading contaminants, removing odors, and decolorizing the wastewater; a recirculation and diffusion line operatively connected to the AOP tank to enable continuous mixing and enhancement of treatment efficiency; and an outlet from the AOP tank configured to discharge the treated water after sufficient residence time, the treated water being suitable for reuse in non-potable applications such as toilet flushing, landscape irrigation, or industrial processes.
A method for treating wastewater using the system of the invention wherein an Advanced Oxidation Process (AOP) system comprising ozone and nano-bubble technology, the method comprising: drawing atmospheric air into an oxygen concentrator and producing a concentrated oxygen stream containing approximately 92% oxygen; supplying the concentrated oxygen stream to an ozone generator to produce ozone gas; introducing wastewater into a venturi ejector; delivering the ozone gas to the venturi ejector and mixing it with the wastewater under controlled pressure using a pressure adjuster valve to ensure effective ozone dissolution; generating ozone-containing nano-bubbles from the mixed stream using a nano-bubble generator to increase the surface contact area between ozone and pollutants; directing the nano-bubble-enriched stream into a static mixer to achieve uniform distribution of ozone throughout the fluid; introducing the uniformly mixed stream into an AOP tank, where oxidation reactions continue to degrade contaminants, eliminate odors, and decolorize the wastewater; continuously recirculating the fluid within the AOP tank through a recirculation and diffusion line to enhance treatment efficiency; and discharging the treated water from the AOP tank after a sufficient residence time, the water being suitable for reuse in non-potable applications including flushing, gardening, or industrial use
The waste water according to the present invention includes domestic wastewater, Industrial wastewater including but not limited to water discharged from factories, processing plants, and other industrial facilities that may contain chemicals, heavy metals, and other pollutants, agricultural wastewater and stormwater and the like.
Table 1, the comparative table outlines the key differences between the MAK HYBRID STP and traditional treatment systems like SBR, MBBR, and MAK ABD with AOP:

Feature SBR (Sequencing Batch Reactor) MBBR (Moving Bed Biofilm Reactor) MAK ABD + AOP Present Invention
Treatment Process Batch process with aeration, settling, and decanting. Continuous process using biofilm-covered media for biodegradation. Anaerobic digestion followed by advanced oxidation with Ozone. Hydrodynamic Cavitation (HC) as pre-treatment, followed by Anaerobic Bio-Digestion (ABD) and AOP (Ozone).
Retention Time Moderate retention time (6-8 hours) Moderate retention time.(4-6 hours) Long retention time (2-2.5 days). Moderate retention time (1-1.5 days due to HC pre-treatment).
Sludge Production High sludge production due to activated sludge. Moderate sludge production. No sludge production. No sludge production.
Energy Consumption High energy consumption due to aeration and mechanical mixing. Moderate energy consumption for aeration and biofilm growth. Low energy due to anaerobic process. Low energy due to efficient HC and ABD processes, with ozone for advanced oxidation.
Effluent Quality Moderate to high, depending on the influent quality. High quality for organic matter removal but may struggle with micro-pollutants. High-quality effluent with minimal contaminants. High-quality effluent with enhanced pollutant degradation through HC pre-treatment and AOP
Removal of Recalcitrant Pollutants Limited removal of persistent chemicals and micro-pollutants. Limited removal of hard-to-remove pollutants. Limited by the anaerobic process, better with AOP. Highly effective at removing micro-pollutants, pharmaceuticals, and other recalcitrant substances due to combined HC, ABD, and AOP.
Operational Complexity Moderate complexity due to batch cycles and process control. Simple but requires regular maintenance of biofilm media. Simple but requires careful control of anaerobic conditions. Moderate complexity, requires managing HC, ABD, and AOP steps effectively.
Cost Moderate to high due to energy needs and maintenance. Moderate due to biofilm maintenance and aeration. Lower operational cost (less energy and no chemicals). Moderate cost, lower operational expenses than traditional systems due to reduced energy consumption and No sludge disposal.
Scalability Highly scalable for various treatment capacities. Easily scalable for large volumes. Less scalable due to long retention times. Highly scalable with shorter retention time and efficient use of resources.
Chemical Usage Chemical dosing may be required for phosphorus and nitrogen removal. Minimal chemical usage, mainly for biofilm maintenance. No chemicals Due to AOP with Ozone, eradicates the need for traditional chemical treatments.
Environmental Impact Moderate environmental impact due to high energy and sludge disposal needs. Moderate impact with some sludge and aeration requirements. Low environmental impact with no sludge production and lower energy consumption. Low environmental impact with no sludge production and lower energy consumption.

Table 2, typical space and power consumption comparison given below:

POWER COMPARISION TABLE FOR A 500 KLD STP PLANT
S.No Particulars Conventional Aerobic System MAK ABD +AOP System MAK HYBRID STP System
Power Rating (KW) Running Hours Units (KWH) Power Rating KW Running Hours Units KWH Power Rating KW Running Hours Units KWH
1 Collection Tank Pump 1.5 11 16.5 1.5 11 16.5 1.5 11 16.5
2 Oil Skimmer 0.375 24 9 0.375 24 9 0 0 0
2 HC Device Pump 0 0 0 0 0 0 1.5 11 16.5
3 Digestion Tank 22 20 440 0 0 0 0 0 0
4 Clarifier Tank 0.75 24 18 0 0 0 0 0 0
5 Sludge Transfer Pump 1.5 3 4.5 0 0 0 0 0 0
6 Filter Feed Tank Pump 2.25 8 18 2.25 8 18 2.25 8 18
7 Sludge Separation 1.5 8 12 0 0 0 0 0 0
8 AOP System 0 0 0 16 16 256 12.16 16 194.56
Total Power Consumption 518 299.5 245.56

The integration of Hydrodynamic Cavitation (HC) as a pre-treatment step, followed by Anaerobic Bio-Digestion (ABD) and post-treatment with Advanced Oxidation Process (AOP) using Ozone, offers a highly effective and efficient multi-stage approach to wastewater treatment. This strategy enhances the overall performance of sewage treatment plants (STPs) by reducing retention times, increasing treatment efficiency, and ensuring that the treated water meets stringent discharge or reuse standards. It also provides several operational, environmental, and economic benefits, making it a sustainable solution for modern wastewater management.
Physicochemical characterization of waste water and treated waste water:

Raw Wastewater was collected from the STP inlet for Physiochemical Characterization. The effluent samples were stored in tightly capped Bottles at 4o C and brought to Room Temperature before analysis.
Table 3 depicts the Physio-chemical Characteristics of the Raw Sewage Water,

Table 3
Parameters Values Unit
pH 6.94 -
Color Mild /Dark Grey -
COD 800 ± 19 mg/l
BOD 210 ± 8 mg/l
TOC 159 ± 6 mg/l
Total Solids 575 ± 20 mg/l
Total Suspended Solids 420 ± 13 mg/l
Total Dissolved Solids 1400 ± 15 mg/l
Total Volatile Solids 433 ± 18 mg/l

Comparison of Tamil Nadu Pollution Control Board (TNPCB) Prescribed Standards against Raw Sewage water:
Table 4
Parameters TNPCB Norms Raw sewage Water
pH 6.0-8.5 6.94
BOD (3-Days) 20 mg/l 208 mg/l
COD 100 mg/l 801 mg/l
TSS 100 mg/l 422 mg/l

Effect of Hydrodynamic Cavitation (HC) Device with Anaerobic Bacterial Digestor (ABD) in Treating Raw Sewage water.

In the present modern life style people tend to extensively use personal care products and non-biodegradable biocides, endorine discruptors, pharmaceutical products and other emerging contamination, domestic waste water becomes more complex and challenging in treating. At the same time current and future regulation demands for better quality of recycled waste water for reuse. The pollution control board mandates necessary to reduce the organic load in the waste water as stated by the pollution control board ( i.e COD < 100 mg/l, BOD < 20 mg/l). However it was challenging to meet the COD and BOD levels of the treated as per the standards. With ABD Technology, we achieved the results with 60-70% of reduction in the Predominant Parameters.
Table 5
MAK HYBRID STP TECHNOLOGY

Parameters Sample Description
Raw Water After HC+ABD Treatment
pH 6.94 7.17
TSS (mg/l) 422 50
BOD (mg/l) 208 70
COD (mg/l) 801 254
Total ammonical nitrogen 77 60
Phosphorous 10.9 9.9

Figure 7 illustrates the physicochemical values of raw waste water and after treatment of HC and ABD.

Effect of AOP Treatment in HC and ABD Treated Water

The COD and BOD is a measure of the organic load present in the wastewater and lower residual COD and BOD is favorable in any industrial or other effulents. As per the TNPCB , a residual COD of 100 mg/l is ideal for distribution of the effluent to Environment. In the currently studied process, the ABD treated water was treated with Standard Ozone dosage (50 GPH) and results indicated significant reduction in the COD (64.6%) with 4 hours under most of the experimental Conditions of Our OFD Technology.We achieved the Results by 4 hour of Ozone Diffusion of Standard Ozone Dosage-50 GPH.

Table 6

Parameters Before AOP Treatment After AOP treatment
pH 7.17 7.1
TSS (mg/l) 50 43
BOD (mg/l) 70 18
COD (mg/l) 254 89.7
Total ammonical nitrogen 60 55
Phosphorous 9.9 9.1

Figure 8 illustrates the physicochemical values of before and after treatment of AOP.

Accordingly, it can be inferred from Table 6, the results that ozone has the potential to break down the complex organic compounds in the effluent to simpler Biodegradable compounds. In similar studies using Ozonation Treatment transformation of Recalcitrant aromatic Compounds to aliphatic Compounds which are probably more responsive to bio-degradation has also been reported.
There is a drastic reduction in COD and BOD from 70 to 18 mg/L and 254 to 89.7 mg/L respectively, total nitrogen reduced from 60 to 55, total suspended solids reduced from 50 to 43 mg/L and phosphorous from 9.9 to 9.1. These results are complied with the pollution control norms. Thus the treated waste water complied with the regulatory norms and much reduced and allowed level of pollutants in the treated water.
Advantage of the present invention:
The system combines Anaerobic Bacterial Digestion (ABD) with Hydrodynamic Cavitation (HC) as a pre-treatment step and Advanced Oxidation Process (AOP) using Ozone as a tertiary treatment, indeed presents a highly innovative solution for wastewater treatment. The system of the present is superior to conventional treatment methods like SBR, MBBR, and ABD with AOP alone, as well as the comparative aspects of our system.
Reduced Retention Time: The traditional ABD system requires a long retention time (typically 2.5 days) to break down organic material effectively. The system reduces this time to just 1 to 1.5 days.
HC Pre-Treatment: HC provides an intense energy input to break down large organic molecules into smaller, more readily digestible compounds. This pre-treatment step significantly improves the efficiency of the Anaerobic Bio-Digester, enabling it to handle the wastewater more quickly and reduce the overall retention time, which is one of the key drawbacks in traditional ABD systems.
Improved Digestion Efficiency: The combination of Hydrodynamic Cavitation and Anaerobic Bio-Digestion optimizes the breakdown of organic matter by enhancing microbial activity. HC generates micro bubbles that create high shear forces, leading to better cell lysis and the release of organic material for anaerobic microbes to break down. Compared to conventional MBBR and SBR systems, which rely on aeration or mechanical processes for microbial growth and waste breakdown, your hybrid system provides more efficient bio degradation. The energy input from cavitation accelerates the microbial digestion process, ensuring higher performance even in a shorter retention time.
No Sludge Production: A significant advantage of your ABD with AOP System is the absence of excess sludge production compared to conventional systems like SBR and MBBR. These systems generate a substantial amount of sludge as they rely on activated sludge processes. On the other hand, Our Hybrid Technology HC with ABD-based systems typically creates No sludge. By integrating AOP using Ozone in the tertiary stage, your system further reduces any potential contaminants in the treated effluent, making it more suitable for reuse and discharge without generating additional waste.
High-Quality treated water output: The combination of Hydrodynamic Cavitation, Anaerobic Bacterial Digestion, and AOP (Ozone) ensures that the treated water meets high-quality discharge or reuse standards. AOP with Ozone is highly effective at degrading organic pollutants, micro-pollutants, and pathogens, ensuring a high level of treatment that conventional methods like SBR and MBBR might not fully achieve.
Potential power savings: Traditional systems like SBR and MBBR typically require significant energy input for aeration and mechanical mixing, leading to higher operational costs. The energy-efficient nature of the Hydrodynamic Cavitation process, combined with the anaerobic treatment in ABD, reduces overall energy consumption while improving treatment efficiency. Ozone-based AOP is an advanced oxidation process that is effective at treating a wide range of pollutants, but it uses less energy than traditional chemical treatments or the extensive aeration systems found in other treatment methods.
Space saving: The hybrid technology MAK HYBRID STP offers the most significant space savings, with the reduction of 20-30% respectively compared to the Conventional activated sludge process. The compact design of this Hybrid technology makes it deal for applications where space is limited.
Increased Treatment Efficiency: Combining HC pre-treatment with ABD and AOP creates a multi-barrier treatment process. Each step complements the others, allowing the system to handle a wide range of contaminants more effectively. The use of HC and AOP minimizes the need for long retention times, reduces sludge production, and increases overall treatment efficiency.
Reduced Operational Costs: By enhancing the biodegradability of the wastewater through HC and optimizing the efficiency of the ABD, the treatment system can reduce energy consumption and operational costs. With reduced retention times and optimized biological and chemical processes, the system requires fewer resources and less maintenance, making it more cost-effective in the long term.
Improved Water Quality: The final treated effluent from the system can meet stringent discharge or reuse standards. The combination of biological and advanced oxidation treatment ensures that a broad spectrum of pollutants, including hard-to-degrade chemicals, organic matter, and pathogens, are effectively removed. The treated water can be safely reused for non-potable applications like irrigation, industrial processes, or even for discharge into sensitive water bodies.
Sustainability and Environmental Impact: The system’s energy-efficient nature, reduction of harmful pollutants, and minimal chemical use contribute to a more sustainable wastewater treatment process. The production of biogas in the ABD can also be harnessed for energy recovery, adding an element of circular economy to the system.
Integration with Sewage Treatment Plants (STPs): By using HC to pre-treat wastewater before it enters the ABD, and applying AOP with ozone for post-treatment, the overall treatment process becomes more compact and efficient. This means that smaller, more energy-efficient treatment facilities can handle larger volumes of wastewater.
Adaptation to Varying Wastewater Quality: The multi-stage treatment approach can adapt to fluctuating wastewater quality, ensuring consistent treatment performance even when influent characteristics change.
Meets Stringent Regulations: The integration of HC, ABD, and AOP with Ozone ensures that the STP can comply with stringent environmental regulations, achieving higher-quality treated water suitable for a range of reuse applications, including industrial and agricultural purposes.
, Claims:1. A system for treating waste water comprising; waste water inlet (1) configured to feed the waste water into the receiving tank (2); an outlet release the waste into grit filter (3) from the receiving tank (2) adapted to remove large and heavier particles and store the waste water in storage tank I (4); the pump (5) transports the wastewater to a Hydrodynamic Cavitation unit (6), which is configured to generate high shear forces and turbulence within the wastewater, thereby facilitating the breakdown of pollutants into smaller particles, the resulting Pre-treated wastewater is subsequently conveyed to storage tank II (7); the anaerobic bacterial digester (8) is configured to digest the particulate matter present in the wastewater and to feed the resulting effluent into a filtering system (9) is configured to remove suspended solids and particulate matter from the effluent, thereby producing a clarified effluent water; the Advanced Oxidation Process (AOP) Tank (10) is configured to degrade remaining toxins, colour, and odour from the clarified effluent, producing treated water, which exits the system and is suitable for non-potable applications such as flushing, irrigation, and industrial use.
2. The system as claimed in claim 1, wherein the grid filter (3) is configured to eliminate coarse solids and sediments from the incoming wastewater supplied via the inlet (1) comprises a the concrete tank (11) has a closed bottom and a removable top cover (14), facilitating access for maintenance and inspection; an inlet cylindrical member (12) provided on the top cover (14) and extends downwardly along the inner wall of the tank and terminates below a grid sheet member (13) positioned within the tank to facilitate the settling of grit and heavy particles; a grid sheet member (13) is positioned internally at a mid-level within the concrete tank (11) and is configured to trap and facilitate the settling of grit and other heavy particles at the bottom of the tank which is supported by grid support bars (15) that are fixed to the removable top cover (14), thereby ensuring stable positioning and facilitating ease of maintenance; the tank is sealed with a top cover to prevent external contamination and to control odour emissions; an air vent (16) is provided on the top cover (14) and is configured to release gases generated during the settling process, thereby maintaining internal pressure balance and ensuring operational safety; an outlet cylindrical member (17) is provided at an upper side portion of the tank (11), above the grid sheet member (13), and is configured to allow treated water to exit the tank and the said outlet is positioned above the sedimentation level to prevent the discharge of settled solids; a manually operated ball valve (18) is installed at the bottom outlet pipe of the tank (19), and is configured to enable controlled discharge of the accumulated grit and settled solids.
3. The system as claimed in claim 1, wherein the Hydrodynamic Cavitation unit (6) is configured to induce high-intensity turbulence and cavitation in the flowing wastewater to facilitate the breakdown of pollutants said unit comprises a hollow cylindrical body (19) having an inlet (21) at a first end and an outlet (23) at a second end; a constricted orifice (22) disposed within the hollow cylindrical body; wherein the wastewater is introduced into the unit through the inlet and is directed at high velocity through the orifice, thereby undergoing a rapid pressure drop that induces the formation of vapor cavities or microbubbles; the vapor cavities or microbubbles collapse in a downstream region of elevated pressure, releasing localized energy in the form of shear forces and shockwaves; wherein the released energy facilitates the disruption of organic and inorganic pollutants present in the wastewater, enhancing their biodegradability; and the treated wastewater, comprising finely dispersed contaminants, exits the unit through the outlet.
4. The system as claimed in claim 1, wherein an anaerobic bacterial digester (8) for treating wastewater, comprising: a housing defining at least three sequentially connected compartments, including a first compartment, an intermediate compartment, and a final compartment; an inlet provided side wall of the housing and configured to introduce wastewater containing fecal and organic matter into the first compartment; a consortium of anaerobic bacteria disposed within the first compartment and configured to initiate degradation of the fecal and organic matter; an immobilization matrix disposed within the first compartment and configured to support bacterial colonization and enhance microbial activity; a first inter-compartmental flow passage provided with a raising cylindrical member connected to the upper end portion of a side wall between the first compartment and the intermediate compartment; a second inter-compartmental flow passage provided with a raising cylindrical member connected to the upper end portion of a side wall between the intermediate compartment and the final compartment, wherein the first and second flow passages are configured to facilitate progressive transfer of wastewater through the compartments; and an outlet provided at a top end portion of the final compartment, configured to discharge treated wastewater having significantly reduced biological oxygen demand (BOD) and chemical oxygen demand (COD), suitable for subsequent treatment.
5. The system as claimed in claim 1, wherein an anaerobic bacterial digester (8) comprising of three interconnected compartments capacity ratio is 40:30:30; the HC treated feacal sludge enters the first compartment (40% capacity) through a falling pipe, initiating anaerobic digestion thereby microorganisms break down complex organic matter, producing biogas and partially treated sludge; the partially treated sludge then flows into the second compartment (30% capacity) via a rising pipe, where further digestion occurs, refining the treatment process; the treated water enters the third compartment (30% capacity) through another rising pipe, where final treatment take place, ensuring high-quality effluent.
6. The system as claimed in claim 1, wherein anaerobic bacterial digester (8) comprising the first compartment having consortium of anaerobic bacteria to disintegrate faecal and organic matter and an immobilization matrix supports bacterial colonization; second compartment comprising digestion and disintegration of organic matter continue where the rising and falling pipes provided to facilitate water flow and further treatment and third compartment configured to makes final adjustments to the biological and chemical oxygen demand (BOD and COD), significantly lowering these levels before the water exits the tank.
7. The system as claimed in claim 1, wherein a rotary screening unit (24) for preliminary solid-liquid separation in a wastewater treatment system, comprising; a cylindrical outer casing (17) having a closed end and a removable closable opposite end; a perforated circular grid sheet (3) concentrically positioned beneath the cylindrical outer casing and configured as a primary filtration medium for capturing non biodegrable coarse solids ,suspended matter and floating debris, while allowing pre-filtered liquid to pass through; an inlet to introduce wastewater and an outlet positioned to receive the filtered liquid discharged through the perforations of the grid sheet for subsequent purification stages; the cylindrical outer casing (17) comprising a longitudinally extending inner tapered surface forming a concentric ring; a shaft having a complementary tapered outer surface, the shaft being configured to interface with the tapered inner surface of the casing to enable stable rotation and alignment of internal components; and a structural support frame (20) configured to provide mechanical stability and maintain proper alignment of the screening unit during operation.
8. The system as claimed in claim 1, wherein the Advanced Oxidation Process (AOP) system (10) for treating wastewater using ozone and nano-bubble technology, the system comprising; an oxygen concentrator configured to draw atmospheric air and produce a concentrated oxygen stream containing approximately 92% oxygen;
an ozone generator configured to receive the concentrated oxygen stream and generate ozone gas therefrom; a venturi ejector configured to receive wastewater and mix it with the ozone gas supplied from the ozone generator, thereby initiating oxidation; a pressure adjuster valve operatively connected to the ozone gas line and configured to regulate the flow rate and pressure of ozone entering the venturi ejector to ensure efficient mixing; a nano-bubble generator configured to produce fine ozone-containing nano-bubbles, thereby enhancing the oxidation efficiency by increasing the contact surface area between ozone and pollutants; a static mixer disposed downstream of the nano-bubble generator and configured to further blend the mixture for uniform ozone distribution; an AOP tank configured to receive the mixed fluid and facilitate ongoing oxidation reactions for degrading contaminants, removing odors, disinfect and decolorizing the wastewater; a recirculation and diffusion line operatively connected to the AOP tank to enable continuous mixing and enhancement of treatment efficiency; and an outlet from the AOP tank configured to discharge the treated water after sufficient residence time, the treated water being suitable for reuse in non-potable applications such as toilet flushing, landscape irrigation, or industrial processes.
9. The system as claimed in claim 1, wherein pumping apparatus (5) adapted to pump a waste water from a Receiving tank (2) to Grit Filter (3), Collection tank 1 (4) to Hydrodynamic Cavitation unit (6) and Filter feed tank (9) to rotary screening unit (24) and AOP Recirculation pump
10. A method for treating wastewater comprising;
a. introducing waste water through an inlet (1) into the receiving tank (2);
b. releasing the waste water through an outlet into grit filter (3) from the receiving tank (2) adapted to remove large and heavier particles and store the waste water in storage tank I (4);
c. transporting the wastewater to a Hydrodynamic Cavitation unit (6), which is configured to generate high shear forces and turbulence within the wastewater, thereby facilitating the breakdown of pollutants into smaller particles, the resulting treated wastewater is subsequently conveyed to storage tank II (7);
d. digesting the particulate matter present in the wastewater in an anaerobic bacterial digester (8) with consortium of bacteria;
e. feeding the digested effluent into a filtering system (9) is configured to remove suspended solids and particulate matter from the effluent, thereby producing a clarified effluent water;
f. treating the waste water in the Advanced Oxidation Process (AOP) Tank (10) to degrade remaining toxins, color, odor,disinfectant of the clarified effluent, producing treated water, which exits the system and is suitable for non-potable applications such as flushing, irrigation, and industrial use.
11. A method for treating wastewater as claimed in claim 9, wherein hydrodynamic cavitation comprising the steps of:
(a) introducing wastewater into a hollow cylindrical unit through an inlet;
(b) forcing the wastewater at high velocity through a narrow orifice disposed within the cylindrical unit;
(c) inducing a pressure drop across the orifice, resulting in the formation of vapor cavities or microbubbles;
(d) collapsing the vapor cavities in a downstream region of higher pressure, thereby releasing localized energy in the form of shear forces and shockwaves;
(e) disrupting organic and inorganic pollutants via said shear forces and shockwaves to enhance their biodegradability; and
(f) discharging the processed wastewater containing finely broken down contaminants through an outlet.

12. A method as claimed in claim 9, wherein anaerobically treating wastewater using a multi-compartment digester comprising:
(a) introducing wastewater containing fecal and organic matter into a first compartment of an anaerobic bacterial digester through an inlet located near the top side wall of the digester;
(b) initiating anaerobic degradation of the fecal and organic matter in the first compartment by means of a consortium of anaerobic bacteria;
(c) providing an immobilization matrix within the first compartment to support bacterial colonization and enhance microbial activity;
(d) progressively transferring the partially treated wastewater from the first compartment to an intermediate compartment through a flow passage located at an upper end portion of a side wall;
(e) further transferring the wastewater from the intermediate compartment to a final compartment through a flow passage located at a upperend portion of a side wall; and
(f) discharging treated wastewater from the final compartment through an outlet located at a top end portion of the compartment, wherein the treated wastewater has significantly reduced biological oxygen demand (BOD) and chemical oxygen demand (COD), rendering it suitable for subsequent treatment.
13. A method as claimed in claim 9, wherein a rotary screening unit comprising:
(a) introducing incoming wastewater into a cylindrical outer casing having a closed end and a removably closable opposite end;
(b) directing the wastewater onto a perforated circular grid sheet concentrically positioned within the unit, the grid sheet configured to trap non bio-degradable coarse solids, suspended matter, and floating debris;
(c) rotating the cylindrical outer casing about a shaft having a tapered outer surface interfacing with a correspondingly tapered inner surface of the casing to ensure concentric alignment and stable rotation;
(d) allowing the filtered liquid to pass through the perforations of the grid sheet into a surrounding collection space;
(e) discharging the pre-filtered wastewater through an outlet for further purification; and
(f) supporting the screening unit on a structural frame to maintain mechanical stability and alignment during operation.
14. A method as claimed in claim 9, wherein an Advanced Oxidation Process (AOP) system comprising ozone and nano-bubble technology, the method comprising:
(a) drawing atmospheric air into an oxygen concentrator and producing a concentrated oxygen stream containing approximately 92% oxygen;
(b) supplying the concentrated oxygen stream to an ozone generator to produce ozone gas;
(c) introducing wastewater into a venturi ejector;
(d) delivering the ozone gas to the venturi ejector and mixing it with the wastewater under controlled pressure using a pressure adjuster valve to ensure effective ozone dissolution;
(e) generating ozone-containing nano-bubbles from the mixed stream using a nano-bubble generator to increase the surface contact area between ozone and pollutants;
(f) directing the nano-bubble-enriched stream into a static mixer to achieve uniform distribution of ozone throughout the fluid;
(g) introducing the uniformly mixed stream into an AOP tank, where oxidation reactions continue to degrade contaminants, eliminate odors, decolorize, disinfect ABD treated water;
(h) continuously recirculating the fluid within the AOP tank through a recirculation and diffusion line to enhance treatment efficiency; and
(i) discharging the treated water from the AOP tank after a sufficient residence time, the water being suitable for reuse in non-potable applications including flushing, gardening, or industrial use.
15. The system as claimed in any preceding claim, wherein waste water includes domestic wastewater, Industrial wastewater including but not limited to water discharged from factories, processing plants, and other industrial facilities that may contain chemicals, heavy metals, and other pollutants, agricultural wastewater and stormwater and the like.