Description:FIELD OF INVENTION
The present invention relates to an improved and active air purification system. More preferably, the present invention provides an air purification system based on bipolar ionization with an improved nano photocatalyst composition for effective disinfection of air, surfaces, and purification thereof. The system has a synergistic combination of bipolar ionization devices and improved photocatalyst composition with high efficacy in disinfecting the air from various organic and biological contaminants. Further, the present invention provides an air purification system with an environment-friendly ultrasound pest repellent that protects HVAC ducts free from harmful pests, insects, rodents, etc. Besides, the present air device does not produce harmful ozone gas (O3) and is therefore environment safe.
BACKGROUND OF THE INVENTION
Air purifiers are known devices used in interior spaces (e.g., homes and commercial public places) to provide fresh air by removing odours, dust, allergens, and other airborne contaminants from the interior air. Typically, most air purifier has air filter membranes to remove small airborne particles and fibers.
However, after treating through a filter membrane some of the harmful pathogens remain in the air or recirculate within the closed room from person to person. Further, organic matter, microorganisms, and smell cannot be removed using filter membranes. Unwanted air contaminants can spread through the supply air duct, centralized air condition system, or HVAC system. HVAC systems are an ideal place for several types of pests, including mice, squirrels, raccoons, and even snakes to hide. They can cause severe damage to your HVAC system. Rodents are also known to carry diseases and can cause allergic reactions by affecting indoor air quality. Mouse droppings and pest droppings that get inside air ducts will also often become trapped and end up dying, which can lead to a nasty, foul odour.
There are various types of pathogens such as bacteria, viruses, protozoa, fungi, Molds, as well as other organic volatile matters that cause infection or health problems.
Indeed, advancements in technology have led to the development of various devices designed to purify air in hospitals, offices, schools, airports, laboratories, and other indoor spaces and making indoor air cleaner, fresher, and COVID-19 virus-free.
An effective air purification system is necessary to avoid contamination from centralized air handling systems that provide air inlets to multiple rooms. The contaminants can enter an HVAC system in a variety of ways, can cause cross-contamination of the areas, and also spread unwanted odours in the system, which possibly affect the indoor air quality and hygiene condition of the said room as well.
Some common types of technological air purification solutions (e.g., a kind of air disinfection and purification smart machine, air filtration, air purification apparatus, etc.) are disclosed in patent literature. A few of the exemplary documents are discussed below.
As per the literature review, there are air purifiers that capture airborne particles, including dust, allergens, microorganisms like bacteria, and some viruses using a high-efficiency particulate air (HEPA) filter. HEPA filters cannot kill these pathogens related to coronavirus. Also, they may not effectively address volatile organic compounds (VOCs) and other odor-causing molecules. They are ineffective in reducing the foul smell of organic matter.
Further, Thermodynamic sterilization technology (TSS) is also used to purify the air by heating the air to a temperature of 200°C. An air purification system using short-wave ultraviolet (UVC) energy is called as a Medical UV air purifier.
Reference may be made to the published literature titled "Low-cost Air Purifier Prototype using a Ventilating Fan and Pump against COVID-19 and Haze Pollution". Six types of household air purifiers, incorporating a HEPA filter, a HEPA filter & electrostatic filter, an air pump, an air pump & ultrasonic wave, a water pump, and a water pump & ultrasonic wave are discussed in this publication.
References may be made to Patent No. CN107511062A titled "Air purifier having low-temperature catalytic combustion (burning) unit and purifying method thereof.” This device is a low-temperature air purifier using some catalyst for converting toxic gas into harmless gas for example conversion of CO into CO2. It has got a detection unit to detect Total Volatile Organic Compound (TVOC), CO; and a temperature control unit.
References may be made to Patent No. CN204901954U titled "Low-temperature plasma air purifier", Patent No. CN106269252A titled "Low-temperature plasma air purifier" and Patent No. CN204234206U titled "Low-temperature plasma air purifier with drawing framework". These devices are based on low-temperature plasma technology.
References may be made to Patent No. US 9,138,504 B2 titled “Plasma driven catalyst system for disinfection and purification of gases”. This document discloses that plasma combined with catalyst enhances the production of new active species, increases the oxidizing power of the plasma discharge, as well as activates the catalyst that additionally contributes towards the disinfection and purification process and the elimination of toxic by-products. The important drawback of this device is that this device reduces the release of toxic Ozone gas but cannot stop producing it. The results show that the said device remains producing a toxic Ozone gas in the environment.
However, the technological solutions for air purification suffer from various limitations such as limited filter life, lack of treatment for all pathogens, and organic compounds or they may produce a harmful Ozone gas, etc. Thus, there remains a need for further contributions in this area of technology. More specifically, a need exists in the area of technology to purify air within a surrounding ambiance and in a safer and greener way.
Acknowledging these challenges, there remains a need for innovative contributions in air purification technology. The present invention aims to fulfil this need by introducing an air purifier system capable of installation in various settings, including rooms, air handling ducts, or open areas.
The described invention aims to address specific challenges related to indoor air quality in various settings, with a focus on reducing total organic content, eliminating foul odours from organic matter, and deactivating airborne pathogens such as COVID-19 and H1N1 influenza A viruses by over 99%.
From the above details of the hitherto known prior art, it is seen that there is a definite need for providing an air purifier with specific capabilities. Developing a device that can effectively convert coronavirus-contaminated air into purified air, while also addressing concerns such as reducing the chance of COVID-19 infection, eliminating odours, and lowering organic volatile compound content, would indeed be valuable. By incorporating these considerations into the development process, the resulting air purifier could effectively contribute to creating a safer and healthier indoor environment, especially in the context of reducing the risk of COVID-19 transmission.
SUMMARY OF THE INVENTION
The present invention provides an air purification system is designed for the effective disinfection of indoor environmental air, targeting viruses, bacteria, particulate matter, and chemical vapors, wherein the system (1) comprises of:
a) perforated photocatalytic reactor/chamber (2) allowing a passage for contaminated air for purification. This reactor serves as the space through which air flows for treatment,
b) high voltage supply (5) responsible for producing a plasma of positively charged and negatively charged bipolar ions. This ionization process contributes to the neutralization of contaminants in the air,
c) at least two spaced positive (4) and negative (4’) electrodes are connected to the power supply (5) and are placed within the first compartment (2). These electrodes play a crucial role in the generation of bipolar ions,
d) ozone-free UV light source disposed in the first compartment (2) and comprising of a light source and power supply. This light source, along with its power supply, contributes to the disinfection process. Ozone-free UV light is chosen to avoid the production of ozone, which can be a concern for indoor air quality,
e) a layer of photocatalyst composition is applied to the internal wall of the perforated photoreactor/chamber (2). This layer enhances the purification process by promoting photocatalytic oxidation, which can break down and neutralize various contaminants in the air,
The UV light source, pair of electrodes (positive and negative), and the layer of photocatalyst composition are characterized by their parallel configuration. This arrangement implies that these components are facing each other in a parallel manner, possibly optimizing the interaction between them for efficient air purification.

Wherein a high voltage power supply (5) is selected between a Positive voltage output of 5000 V and a negative voltage output of 5000 V to emit bipolar ions and UV light source provided light having radiation wavelength between 200 to 380 nm.
In accordance to present invention, the photocatalyst composition consisting of 45 to 65 % w/w of Titanium (IV) dioxide nanoparticles, 0.1 to 1 % w/w of doped metals, 0.1 to 4.5 % w/w surfactant and 35 to 55 % w/w binder on dried basis.
Wherein the photocatalyst composition layers are selected from 1 to 3 coating of a solution prepared from composition of 0.4 to 0.6 % w/v of Titanium (IV) dioxide nanoparticles, 0.001 to 0.1 % w/v of doped metals, 0.001 to 0.5 % w/v surfactant, 0.3 to 0.5 % w/v binder in water as a solvent.
In accordance to one more embodiment, the wherein Titanium (IV) dioxide forms are selected from a combination of Anatase and Rutile forms in an equal weight ratio and said nanoparticles range for titanium dioxide is selected between 3 nm to 100 nm.
The doped metals are selected from a combination of Copper, Platinum, Gold, and Silicon in an equal weight ratio.
The binder is selected from polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene Sorbitan monooleate, etc.
The surfactant selected from Sodium dodecyl Sulfate, Sodium Lauryl Sulfate, Sodium Laureth Sulfate, Sodium dodecyl benzene sulfonic acid, Cardanol-based surfactants, etc.
The perforation on chamber or photoreactor (2) is not limited to shape, size, and location on the said chamber (2).
The bipolar power supply (5) is selected from the direct electric supply, battery, and combination thereof.
Further, the said perforated chamber or photoreactor (2) also comprises spots/emitters for Ultrasonic pest-repellent emits high-frequency sound waves.

BRIEF DESCRIPTION OF THE DRAWINGS
For a comprehensive understanding of the present invention, reference accompanied by the illustrations. It is to be understood; however, each figure is provided for illustrative purposes and description only and is not intended to define the absolute limits of the present invention.

FIGURE NO. 1: A schematic cross-section view presents the core structure of the air purification system (1) in accordance with the present invention.
FIGURE NO. 2: This schematic illustration showcases the integration of the air purification system (1) within the HVAC duct system, demonstrating its applicability in centralized air handling systems.
FIGURE NO. 3: A perspective outer view of the air purification system (1) provides a visual representation of its external features and design elements.
FIGURE NO. 4: The graph illustrates the percentage removal of Particulate matter with an average diameter of 1.0 microns over time, highlighting the efficiency of the present invention.
FIGURE NO. 5: The graphical representation depicting the percentage removal of Particulate matter with an average diameter of 2.5 microns over time, demonstrates the system’s effectiveness.
FIGURE NO. 6: The graph illustrates the percentage removal of Particulate matter with an average diameter of 10.0 microns over time, showcasing the comprehensive filtration capabilities of the present invention.
FIGURE NO. 7: The graph illustrates the percentage removal of Formaldehyde over time, revealing the air purification system's proficiency in eliminating specific chemical contaminants.
FIGURE NO. 8: The graph illustrates the percentage removal of Total volatile organic compounds over time, providing insights into the system’s ability to handle diverse organic pollutants.
FIGURE NO. 9: The illustration demonstrates the impact of different catalyst coating layers on the percentage removal of Formaldehyde, offering valuable insights into the catalyst’s role in air disinfection and purification.
FIGURE NO. 10: The illustration demonstrates the impact of different catalyst coating layers on the percentage removal of Total volatile organic compounds, underscoring the importance of catalyst composition in the purification process.
FIGURE NO. 11: The graph illustrates the percentage removal of Particulate matter with an average diameter of 1.0 microns over time, specifically focusing on the correlation with catalyst composition as per the present invention.
FIGURE NO. 12: The graph illustrates the percentage removal of Particulate matter with an average diameter of 2.5 microns over time, specifically focusing on the influence of catalyst composition as per the present invention.
FIGURE NO. 13: The graph illustrates the percentage removal of Particulate matter with an average diameter of 10.0 microns over time, emphasizing the impact of catalyst composition in the context of the present invention.
FIGURE NO. 14: The illustration highlights the combined effect of a catalyst and plasma ionizer on the percentage removal of Formaldehyde, showcasing the synergistic impact of these contaminants by the present invention.
FIGURE NO. 15: The illustration highlights the combined effect of a catalyst and plasma ionizer on the percentage removal of Total volatile organic compounds, showcasing the synergistic impact of these contaminants in accordance with the present invention.
FIGURE NO. 16: The graph illustrates the effect of a combination of a catalyst and plasma ionizer on the percentage removal of Particulate matter with a diameter of 1.0 microns over time, emphasizing the role of catalyst composition in conjunction with plasma ionizer as per the present invention.
FIGURE NO. 17: The graph illustrates the effect of a combination of a catalyst and plasma ionizer on the percentage removal of Particulate matter with a diameter of 2.5 microns over time. It provides insights into how variations in catalyst composition, along with plasma ionization, influence the removal of mid-sized particulate matter.
FIGURE NO. 18: The graph demonstrates the effect of the combination of a catalyst and plasma ionizer on the percentage removal of particulate matter with a diameter of 10.0 microns over time, focusing on the interplay between catalyst composition and plasma ionization in the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The following description of the present specification uses some terms that have the general meanings indicated below:
The term “plasma”, as used herein, refers to air ionization as well as photocatalysis technologies, both positive and negative ions are produced (called bipolar ionization), with the result being a uniform mixture of +/- air ions as well as active species of free radicals.
Hence, the mixture of ionized gas (plasma), is created by altering the naturally occurring oxygen and humidity in the air in the presence of a UV light source and applying high voltage.
The described invention involves an enhanced air purification system that combines bipolar ionization with an improved photocatalyst composition, specifically utilizing antimicrobial properties and photocatalytic oxidation efficacy of the Titanium (IV) Dioxide nanoparticle-based photocatalytic formulation. The system is designed for integration into Heating, Ventilation, and Air Conditioning (HVAC) ducts. This allows for the purification of the air circulating through the HVAC system, ensuring comprehensive coverage throughout the building.
In an embodiment and referring to figures no. 1, 2, and 3, the present invention provides an air purification system (1) designed for effective disinfection of indoor environmental air (100) from viruses, bacteria, particulate matter, and chemical vapors and obtaining clean air (101), wherein the system (1) comprises of:
a) perforated photocatalytic reactor (2) allowing a passage for contaminated air for purification,
b) high voltage supply (5) for producing a plasma of positively charged and negatively charged bipolar ions,
c) at least two spaced positive (4) and negative (4’) electrodes connected to the power supply (5) and disposed in the first compartment (2),
d) ozone-free UV light source providing light having radiation wavelength between 200 to 280 nm disposed in the first compartment (2) and comprising of a light source and power supply,
layer of photocatalyst composition on an internal wall of the perforated reactor (2);
Characterized by that the UV light source, pair of electrodes, and layer of catalyst composition are parallelly facing each other.
e) device produces adjustable ultrasound waves (8) placed on the base of the perforated photo tube.

Wherein high voltage power supply (5) is selected between a Positive voltage output of 5000 V and a negative voltage output of 5000 V to emit bipolar ions.
In accordance with one more embodiment, the present invention provides an improved photocatalyst composition consisting of 45 to 65 % w/w of Titanium (IV) dioxide nanoparticles, 0.1 to 1 % w/w of doped metals, 0.1 to 4.5 % w/w surfactant and 35 to 55 % w/w binder on the dried basis.
The said composition is prepared by preparing a solution of photocatalyst composition consisting of 0.4 to 0.6 % w/v of Titanium (IV) dioxide nanoparticles, 0.001 to 0.1 % w/v of doped metals, 0.001 to 0.5 % w/v surfactant, 0.3 to 0.5 % w/v binder in water as a solvent.
The described invention involves an innovative photocatalytic formulation utilizing modified nanoparticles of Titanium dioxide (IV) in conjunction with germicidal ultraviolet (UVC-254 nm) light to initiate a photocatalytic oxidation mechanism. This technology generates hydroxyl radicals (∙OH), superoxide ion radicals (∙O2-), and hydrogen peroxide ions (H2O2-), among others, through the photocatalytic reaction. Additionally, the generation of plasma containing bipolar ions is a notable aspect of the invention. These highly reactive ions and radicals, including hydroxyl radicals, are dispersed in the air to neutralize a wide range of airborne particles, including microorganisms, organic pollutants, particulate matter, gases, odours, etc.
The use of modified Titanium dioxide (IV) nanoparticles and UVC-254 nm lights initiates a photocatalytic oxidation mechanism. This process generates powerful oxidizers, including hydroxyl radicals (∙OH) and superoxide ion radicals (∙O2-), known for their effectiveness in neutralizing contaminants. The choice of UVC-254 nm lights is in the germicidal wavelength range, known for its ability to initiate the photocatalytic reaction and effectively destroy microorganisms.
Hydroxyl radicals are considered safe and potent oxidizing agents with a high oxidation potential of 2.80 V. The ∙OH attacks the cell membrane of microorganisms, causing membrane damage, destroying sugar groups, and inducing DNA base sequence disintegration, ultimately leading to cell death and mutations. This invention addresses the potential induction of mutations and cell death in microorganisms, suggesting a thorough disruption of indoor biological contaminants at the molecular level.
Moreover, the device produces variable ultrasonic frequencies (30 kHz - 55 kHz) which are capable of repelling, disorienting, and disrupting acoustic communications for pests and insects. An ultrasonic pest-repellent system emits high-frequency sound waves that keep the HVAC system free from harmful pests and rodents.
In summary, the described air purification system integrates advanced photocatalytic oxidation technology with germicidal ultraviolet lights and the generation of plasma containing bipolar ions along with ultrasonic waves. The combination aims to provide an effective and comprehensive solution for neutralizing a wide range of indoor contaminants, emphasizing both safety and efficiency in the process.
In the subsequent examples, only preferred embodiments of the invention are explicitly described, and it will be acknowledged that variations in compositions and external parameters of the invention are possible, without deviating from the spirit and intended scope of the invention.

EXAMPLES
The examples provided below serve as illustrations and should not be interpreted to restrict the scope of the invention.
Example: 1: Development of different photocatalyst compositions as per the present invention
A: Photocatalyst formulations preparation and coating: In the present study, various formulations of Titanium (IV) oxide nanoparticles doped with nanoparticles of precious transition metals (Cu, Au, Si & Pt) have been used for photocatalytic and antimicrobial studies. The doping of precious transition metal nanoparticles onto Titanium (IV) oxide was achieved through the metal ion adsorption method. The procedure involved the addition of a known quantity of precious metals (0.01%) was added to the aqueous solution of TiO2 (0.5%), followed by stirring using a magnetic stirrer. This metals-TiO2 sol was diluted as required and allowed to stand for 24 hours before being utilized for photocatalytic coating. Water served as the solvent in this process.
B. Different Photocatalyst formulations:
1. Catalyst A (nanoparticles mixture of Anatase TiO2 and Rutile TiO2 forms)
Ingredient Name % w/v
(Formulation-1)
Mixture of Anatase TiO2 and Rutile TiO2 forms nanoparticles (1:1) 0.5
Water 99.5
Table No. 1
2. Catalyst B (nanoparticles mixture of Anatase TiO2 and Rutile TiO2 forms doped with quad metals: Cu, Si, Au & Pt)

Ingredient Name % w/v
(Formulation-2)
Anatase TiO2 and Rutile TiO2 forms nanoparticles (1:1) 0.5
Dopants precious transition metals nanoparticles in equal weight ratio (Copper, Platinum, Gold, and Silicon) nanoparticles 0.01
Water 99.5 (qs)
Table No. 2

3. Catalyst C (nanoparticles mixture of Anatase TiO2 and Rutile TiO2 forms doped with quad metals: Cu, Si, Au & Pt, binder, and surfactant)
Ingredient Name Concentration in % w/v for solution
Formulation-3 Formulation-4 Formulation-5
Anatase TiO2 and Rutile TiO2 forms nanoparticles 1:1 0.5 0.4 0.6
Dopants precious metals in equal weight ratio (Copper, Platinum, Gold and Silicon) nanoparticles 0.01 0.008 0.0015
Water 99 (qs) 99 (qs) 99 (qs)
Surfactant (Sodium dodecyl Sulfate) 0.01 0.001 0.05
Binder (Polyoxyethylene (20) sorbitan monolaurate) 0.5 0.3 0.5

Table No. 3

Ingredient Name Concentration in % w/w on dried basis
Formulation-3 Formulation-4 Formulation-5
Anatase TiO2 and Rutile TiO2 forms nanoparticles 1:1 61.1 44.3 51.7
Dopants precious metals in equal weight ratio (Copper, Platinum, Gold, and Silicon) nanoparticles 0.97 0.17 0.86
Surfactant (Sodium dodecyl Sulfate) 1.22 0.11 4.31
Binder (Polyoxyethylene (20) sorbitan monolaurate) 36.71 55.42 43.13
Table No. 4
4. Catalyst D (Nanoparticles of TiO2 Anatase form & Precious quad metals: Cu, Au, Si, and Pt).
Ingredient Name % w/v (Formu-6)
Anatase Titanium (IV) dioxide nanoparticles 0.5
Dopants precious metals in equal weight ratio (Copper, Platinum, Gold, and Silicon) nanoparticles 0.01
Water 99 (qs)
Table No. 5
Example: 2: Effect of combination of photocatalyst composition and plasma ionizer for effective air purification.
In this example, four catalyst formulations (A, B, C, and D) were combined with plasma ionizer technology to study their effectiveness in the photocatalytic oxidation of Total Volatile Organic Compounds (TVOC), formaldehyde, odours, and particulate matter with diameters ranging between 0.1 to 10 microns (PM1.0, PM2.5, and PM10). Catalyst C demonstrated exceptional antimicrobial and photocatalytic activity. Referencing Figures 4, 5, 6, 7, and 8, a significant reduction in formaldehyde, VOCs, and PM (1.0, 2.5, and 10) was achieved with the formulation of catalyst C. Third-party testing facilities assessed the combined technologies for cell toxicity, antimicrobial efficacy against harmful bacteria and viruses (SARS-CoV-2, H1N1 Influenza A, Bacteriophage MS2 virus, etc.), and mold species.
Conclusion: The combination of UV with photocatalyst technology effectively tackled gas contaminants (Formaldehyde & TVOCs), plasma emitter technology excelled in particulate matter elimination, and pest-repellent technology addressed harmful pests and rodents. Notably, the combination of UV with photocatalyst and plasma emitter technology proved effective against all three types of indoor air pollutants (microbes, gases, and particulates).

Example: 3: Application of Catalyst layer and Effect of coating of catalyst composition:
In this example, a solution of metal-doped TiO2 formulation prepared in Example 1, Table 3, was applied to a metal support. The application was done using a brush, and for uniform coating, 2-3 layers of the solution were applied. Metal panels were dried in between catalyst coating preferably at room temperature (other suitable methods of drying include over-drying or blow air drying temperatures between 25 to 40 °C). The coated metal substrate was exposed to Ultraviolet light (UVC) in a closed chamber. Upon illumination, photons were absorbed by the TiO2 catalyst surface, forming oxidizing and reducing sites (hole & e-pair), leading to the generation of reactive hydroxyl radicals and superoxide ions.
The hydroxyl radicals attacked and oxidized contaminants, resulting in harmless by-products like water, oxygen, and carbon dioxide. The reduction of gas contaminants (Total Volatile Organic Compounds and formaldehyde) and particulate matter (PM2.5 & PM10) was observed. Figures 9, 10, 11, 12, and 13 represent the effect of the catalyst C coating layer on the oxidation of Formaldehyde, Volatile Organic Compounds (VOCs), and particulate matter.
Example: 4: Testing of Antimicrobial properties of catalyst C formulation
Test standard: JIS Z 2801: 2010
Test Bacteria: 1. Escherichia coli NCIM 2065/ ATCC 8739
2. Staphylococcus aureus- NCIM 5345/ ATCC 6538
Test results: The plates coated with the improved photocatalyst composition (Catalyst C) showed 99.999% effectiveness against Escherichia coli and Staphylococcus aureus. This indicates that Catalyst C formulation exhibits excellent antimicrobial activity.
Example: 5: Effect of Combination of catalyst C formulation, UV, and Plasma emitter Technologies on air purification:
The combination of plasma emitter with UV light source and Catalyst C with two coats was studied. The results for the oxidation of Formaldehyde and Volatile Organic Compounds (VOCs) and the reduction of particulate matter are represented in Figures 14, 15, 16, 17, and 18.
Wherein,
nanoX study: Only Catalyst C formulation with UV light.
plasmOX study: Only bipolar ionization was used without UV & photocatalyst composition coating.
nanoX + plasmOX: Combination of bipolar ionization devices and improved photocatalyst composition.
Example: 6: Combination of catalyst C formulation, UV, and Plasma emitter Technologies effectively deactivates airborne SARS-CoV-2 (COVID-19 virus)
Tested by: The ICMR recommended the Government Institute (CSIR-Centre for Cellular and Molecular Biology, Hyderabad) to investigate the antiviral efficacy of technologies.
Results: The air purification device (1) technologies showed 95%, 96%, 97%, 98%, and 99.4% viral reduction in 5, 10, 15, 30, and 45 min. respectively. The viral particles reduced from 105.8 to 103.6 at 45 minutes.
Additional study: A combination of Technologies effectively deactivates the airborne H1N1 Influenza A virus (A/Puerto Rico/8/1934 (H1N1)) infected BHK-21 cell line.
Study conducted by: Viral Immunology lab, Dept. of Bioscience and Bioengineering, Indian Institute of Technology, Guwahati, Assam.
Exposure to the air purification system (1) as per the present invention for 10 mins, 15 mins, and 20 mins showed a significant reduction in virus replication compared to an unexposed virus. The maximum reduction was observed in 15 minutes. Conclusively, these results demonstrate that the air purification system (1) technology exhibits excellent antiviral activity against airborne Influenza A virus A/Puerto Rico/8/1934 (H1N1)) in cultured BHK-21 cells.
Observation:
• The synergy of air purification system (1) technologies demonstrates control over mold growth.
• Air purifiers powered by a combination of bipolar ionization devices and improved photocatalyst composition air purification systems (1) effectively eliminate hospital and washroom/restroom odors.

Cell toxicity study of air purifiers powered by air purification system (1) technologies on Human epithelial lung cells (A549).
Study conducted by: Viral Immunology lab, Dept. of Bioscience and Bioengineering, Indian Institute of Technology, Guwahati, Assam.
Result: After prolonged exposure of 2 hours, the air purifier with air purification system (1) technologies showed cultured cell viability identical to the control. This confirms the non-toxic nature of the air purifiers and the safety of hydroxyl radicals and bipolar ions formed by the device for building occupants.

ADVANTAGES OF THE INVENTION
The present product offers various advantages:
1. Technologies tested & certified to deactivate >99% airborne COVID-19 and H1N1 influenza A viruses.
2. The photocatalyst formulation (TiO2 nanoparticles doped with nanoparticles of precious metals) prepared in our laboratory shows excellent antimicrobial activity, 99.99% against tested bacteria.
3. The improved photocatalyst composition formulation shows excellent photocatalytic oxidation properties and reduces organic matter such as VOCs, odors, and pathogenic microbes.
4. Technologies certified for their non-toxic nature to building occupants, tested on Human lung cells (cell toxicity study).
5. Technologies have been tested and certified solutions to inhibit Molds and fungi species' indoor growth.
6. Combination of technologies proven to reduce different types of odours including hospital odour, restroom odour, urine odours, food odours, smoke odours, formaldehyde, strong cleaning solvent odours, and other Volatile organic compounds (VOCs).
7. The combination of air purification system (1) technologies effectively affects all three types of indoor pollutants (Particulates, Microbes, and Gases).
8. The incorporation of an ultrasonic pest-repellent system in the ducted type model of the HVAC system adds a valuable feature to help keep the ductwork free from rodents and pests.
9. These air purification technologies do not produce any kinds of by-products in the air during treatment.
10. IAQ solutions based on air purification system (1) technologies are environment-friendly throughout the different stages of their life cycle which include the Design Stage, Raw Material Selection, Manufacturing Process, Product Performance during Use, Disposal, and Recycling.
11. Certified Greener technologies: Certified by the Confederation of Indian Industry- Green Products & Services Council, Indian Green Building Council.
, Claims:We Claims;
1. An air purification system (1) is designed for the effective disinfection of indoor environmental air, targeting viruses, bacteria, particulate matter, and chemical vapors, wherein the system (1) comprises of:
a) perforated photocatalytic reactor/chamber (2) allowing a passage for contaminated air for purification. This reactor serves as the space through which air flows for treatment,
b) high voltage supply (5) responsible for producing a plasma of positively charged and negatively charged bipolar ions. This ionization process contributes to the neutralization of contaminants in the air,
c) at least two spaced positive (4) and negative (4’) electrodes are connected to the power supply (5) and are placed within the first compartment (2). These electrodes play a crucial role in the generation of bipolar ions,
d) ozone-free UV light source disposed in the first compartment (2) and comprising of a light source and power supply. This light source, along with its power supply, contributes to the disinfection process. Ozone-free UV light is chosen to avoid the production of ozone, which can be a concern for indoor air quality,
e) a layer of photocatalyst composition is applied to the internal wall of the perforated photoreactor/chamber (2). This layer enhances the purification process by promoting photocatalytic oxidation, which can break down and neutralize various contaminants in the air,
Wherein, the UV light source, pair of electrodes (positive and negative), and the layer of photocatalyst composition are characterized by their parallel configuration and this arrangement implies that these components are facing each other in a parallel manner, possibly optimizing the interaction between them for efficient air purification.

2. The air purification system (1) as claimed in claim 1, wherein a high voltage power supply (5) is selected between a Positive voltage output of 5000 V and a negative voltage output of 5000 V to emit bipolar ions.
3. The air purification system (1) as claimed in claim 1, wherein UV light source provided light having radiation wavelength between 200 to 380 nm.
4. The air purification system (1) as claimed in claim 1, wherein photocatalyst composition consisting of 45 to 65 % w/w of Titanium (IV) dioxide nanoparticles, 0.1 to 1 % w/w of doped metals, 0.1 to 4.5 % w/w surfactant and 35 to 55 % w/w binder on dried basis.
5. The air purification system (1) as claimed in claim 1, wherein photocatalyst composition layers are selected from 1 to 4 coating of a solution consisting of 0.4 to 0.6 % w/v of Titanium (IV) dioxide nanoparticles, 0.001 to 0.1 % w/v of doped metals, 0.001 to 0.5 % w/v surfactant, 0.3 to 0.5 % w/v binder in water as a solvent.
6. The air purification system (1) as claimed in claims 4 and 5, wherein doped metals are selected from a combination of Copper, Platinum, Gold, and Silicon in an equal weight ratio.
7. The air purification system (1) as claimed in claim 6, wherein Titanium (IV) dioxide forms are selected from a combination of Anatase and Rutile forms in an equal weight ratio.
8. The air purification system (1) as claimed in claims 4 and 5, wherein the nanoparticles range for titanium dioxide is selected between 3 nm to 100 nm.
9. The air purification system (1) as claimed in claims 4 and 5, wherein the binder is selected from polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene Sorbitan monooleate, etc.
10. The air purification system (1) as claimed in claims 4 and 5, wherein the surfactant selected from Sodium dodecyl Sulfate, Sodium Lauryl Sulfate, Sodium Laureth Sulfate, Sodium dodecyl benzene sulfonic acid, Cardanol-based surfactants, etc.
11. The air purification system (1) as claimed in claim 1, wherein the perforation on chamber or photoreactor (2) is not limited to shape, size, and location on the said chamber (2).
12. The air purification system (1) as claimed in claim 1, wherein the bipolar power supply (5) is selected from the direct electric supply, battery, and combination thereof.
13. The air purification system (1) as claimed in claim 1, wherein the perforated chamber or photoreactor (2) also comprises spots/emitters for Ultrasonic pest-repellent emits high-frequency sound waves.