The present invention relates to a system for disinfecting and sanitizing environments.

Nowadays it is absolutely necessary to show due care in operations to disinfect, clean and sanitize various environments, for example hospitals, clinics etc., in the attempt to reduce to the minimum the presence of bacteria and of contaminant agents, both in areas of high and medium risk and also in areas of low risk where, in any case, the presence of microorganisms (pathogens and otherwise) can determine contagion between persons: patients and/or immune-compromised individuals, health workers, visitors.

The solutions adopted today for the disinfection and the sanitization of environments usually entail the use of antiseptic and/or disinfectant solutions which have different concentrations according to the environment to be treated.

The disinfectant used most commonly is sodium hypochlorite, which however presents a certain number of problems.

In particular, it has been found that microorganisms have a certain tendency to resist its disinfectant action.

Furthermore, if solutions are used with a low percentage of dilution, it is necessary that the operators follow a series of precautions during its use.

Finally, it is noted that its disinfectant capacity deteriorates extremely rapidly.

The same considerations apply for other disinfectants or sanitizers that are usually employed.

The aim of the present invention is to provide a system for disinfecting and sanitizing environments which is capable of improving the known art in one or more of the above mentioned aspects.

Within this aim, an object of the invention is to make available a system for disinfecting and sanitizing environments which makes it possible to keep environments under control in real time so as to guarantee the absence of bacteria and of contaminant agents.

A still further object of the invention is to provide a system for disinfecting and sanitizing environments that is highly reliable, easy to implement and of low cost.

This aim and these and other objects which will become better apparent hereinafter are achieved by a system for disinfecting and sanitizing environments according to claim 1 , optionally provided with one or more of the characteristics of the dependent claims.

Further characteristics and advantages of the invention will become better apparent from the following detailed description a preferred, but not exclusive, embodiment of the system for disinfecting and sanitizing environments according to the invention.

The system for disinfecting and sanitizing environments according to the invention comprises at least one of the four elements listed below:

- a first element, which comprises at least one device for purifying air by way of hydrated photocatalytic oxidation, the device for purifying air being adapted to emit into the environment hydroxide ions, radicals, peroxide radicals, hydroperoxides which, through the action of light and of air humidity, activate a reaction to break down harmful organic and inorganic substances;

- a second element, which comprises a liquid solution which can be applied to the surfaces to be sanitized and comprises silver ions in citric acid;

- a third element, which comprises at least one ozone generator device adapted to maintain a substantially constant percentage of ozone in the environment;

- a fourth element, which comprises at least one device for filtering air combined with an element for sanitizing air by way of hydrated photocatalytic oxidation.

According to a preferred embodiment, the system for disinfecting and sanitizing environments comprises at least two of the four elements listed above.

In a first practical embodiment, the system for disinfecting and sanitizing environments comprises:

- at least one device for purifying air by way of hydrated photocatalytic oxidation, the device for purifying air being adapted to emit into the environment hydroxide ions, radicals, peroxide radicals, hydroperoxides which, through the action of light and of air humidity, activate a reaction to break down harmful organic and inorganic substances;

- a liquid solution which can be applied to the surfaces to be sanitized and comprises silver ions in citric acid.

In a second practical embodiment, the system for disinfecting and sanitizing environments comprises:

- at least one device for purifying air by way of hydrated photocatalytic oxidation, the device for purifying air being adapted to emit into the environment hydroxide ions, radicals, peroxide radicals, hydroperoxides which, through the action of light and of air humidity, activate a reaction to break down harmful organic and inorganic substances;

- at least one ozone generator device adapted to maintain a substantially constant percentage of ozone in the environment.

In a third practical embodiment, the system for disinfecting and sanitizing environments comprises:

- a liquid solution which can be applied to the surfaces to be sanitized and comprises silver ions in citric acid;

- at least one ozone generator device adapted to maintain a substantially constant percentage of ozone in the environment.

According to further embodiments, the system for disinfecting and sanitizing environments comprises the first element and the fourth element, or the second element and the fourth element, or the third element and the fourth element. Advantageously, in a preferred embodiment, the system for disinfecting and sanitizing environments comprises three of the elements listed below:

- a first element, which comprises at least one device for purifying air by way of hydrated photocatalytic oxidation, the device for purifying air being adapted to emit into the environment hydroxide ions, radicals, peroxide radicals, hydroperoxides which, through the action of light and of air humidity, activate a reaction to break down harmful organic and inorganic substances;

- a second element, which comprises a liquid solution which can be applied to the surfaces to be sanitized and comprises silver ions in citric acid;

- a third element, which comprises at least one ozone generator device adapted to maintain a substantially constant percentage of ozone in the environment;

- a fourth element, which comprises at least one device for filtering air by way of hydrated photocatalytic oxidation.

In this regard, the system for disinfecting and sanitizing environments comprises the first element, the second element and the third element, or the first element, the second element and the fourth element, or the first element, the third element and the fourth element, or the second element, the third element and the fourth element.

According to a preferred embodiment, the system for disinfecting and sanitizing environments comprises the first element, the second element, the third element and the fourth element.

Conveniently, the system comprises a device for monitoring the microorganisms that are present in the environment.

The monitoring device is adapted to perform monitoring in real time, which makes it possible to control the level of particulate and microbiological contamination present in the environment at all times. Preferably, the monitoring device comprises a sampling device.

By way of example, the sampling device operates by monitoring through a probe that samples the air by bringing it into a reading chamber which is associated with a laser sensor.

The first element, as well as the fourth element, substantially makes use of photocatalysis, the natural phenomenon wherein a substance, called a photocatalyst (Ti0 ₂ ), modifies the speed of a chemical reaction through the action of light (natural or artificial); its operation imitates chlorophyll photosynthesis. The chemical process that underlies this is in fact an oxidation which begins by virtue of the combined action of light (from the sun or industrial/artificial light) and of humidity in the air.

The two elements (light and air), in contact with the coating of surfaces, favor the activation of the reaction and the consequent breakdown of organic and inorganic substances.

Precisely because of its intense oxidative capacity, photocatalytic oxidation can effectively sanitize, deodorize and purify air, water and several surfaces. Photocatalysis not only kills bacteria cells, but also breaks them down. It has been verified that titanium dioxide is more effective than any other antibacterial agent, because the photocatalytic reaction occurs even when there are cells covering the surfaces and the bacteria are actively multiplying: by activating on the surface and bypassing the biofilm created by the bacteria, it is effective where traditional chemical sanitizing agents perform less well.

Furthermore even the endotoxin, deriving from the cell death, is broken down by the photocatalytic action. Titanium dioxide does not degrade and it exhibits a long-term antibacterial and virucidal effect.

Generally, disinfection with titanium dioxide is 3 times more effective than that obtained with chlorine and 1.5 times more effective than that of ozone.

Viruses are destroyed in a manner similar to bacteria. Viruses, such as HIV, are generally susceptible to the devastating effects of photosensitization.

Conveniently, the device for purifying air comprises at least one titanium dioxide surface doped with gold, silver, copper, rhodium and nano- nickel, which is adapted to increase the kinetic reaction rate and the lifetime of the hydroxyl radicals generated when it is subjected to UV irradiation.

The effect of the dopants on the titanium dioxide (Ti0 ₂ ) surface increases the lifetime of the hydroxyl radicals that are generated when the surface is subjected to UV irradiation.

The metallic copper operates as an electron accumulation center, thus hindering the recombination of such radicals; two hydrophilic gels, which are also spread in single-electrode mode, have the function of hydrating the coating and react in combination with all the metal catalysts in order to break down the ozone (by donating hydrogen to ozone) and form radicals of hydroxide ions, as well as hydroperoxides such as hydrogen and H0 ₂ peroxide radicals, which are desirable reaction products from the breakdown of ozone owing to their strong oxidant properties, which together with UVC radiation increases the germicidal effect.

The UV germicide lamp destroys the germs that pass through the UVC light rays.

The light rays of the UV lamp react with the nano-nickel catalyst to produce catalytic molecules.

The catalytic molecules target and destroy carbon-based molecules, converting them to carbon dioxide and harmless water.

The second element comprises the liquid solution comprising silver ions in citric acid and it has a stabilized complex in which each silver ion is weakly bound to citric acid ions.

The transport proteins, ascribed to over 500 families, pass through the cellular membrane and transport different molecules, which belong in general to two categories: nutrients and endogenous substances necessary to the cellular function.

From the structural point of view, these transporters are constituted by 12 helices which go back and forth in the thickness of the membrane to form a channel through which the substances are transported inside the cell. In the case of bacteria, the transport proteins recognize the citric acid as food and therefore transfer it into the microorganism. Once they have penetrated inside, the silver cations quickly react with the negatively charged groups, causing irreversible damage both to the proteins and to the DNA and RNA of the bacteria, blocking their metabolic and reproductive functions, and finally resulting in their death.

In essence:

- the silver cations inhibit the multiplication of the bacteria, irreversibly damaging their DNA and RNA, with production of insoluble silver halides;

- the silver ions bind at the tissue protein level causing structural changes to the cellular and intracellular wall, and also in the nuclear membranes of the bacteria themselves;

- the silver ions in citric acid also bind the electrons of sulfur, oxygen and nitrogen of the bacteria, with consequent precipitation and coagulation of some proteins of the microorganisms.

The ozone generator device makes it possible to destroy fungi.

The antiseptic power of ozone makes it possible to eliminate bacteria and neutralize viruses that are difficult to attack with other methods.

The air filtration device is paired with an element for sanitizing air by way of hydrated photocatalytic oxidation, and it can comprise a metallic and/or plastic structure of various shapes and sizes containing air filters of different filtering capacity up to absolute filtration capacity (HEPA filters) and a system composed of one or more apparatuses of various shapes and sizes that are capable of eliminating microbial, bacterial, viral, mould and spore loads by way of hydrated photocatalytic oxidation. Conveniently, the filtration device is associated or associable with a duct for delivering the air into the environment to be sanitized.

According to a further aspect, the system comprises an apparatus which is adapted to use a process of oxidation-reduction and of low-level production of negative airborne ions and ozone in order to decompose organic substances and break down organic and inorganic polluting substances.

In particular, the apparatus is intended for the production, with low- temperature plasma, of negative ions, with the function of neutralizing substantially all the polluting agents present in the air.

Also provided is at least one ozonizer device for the production of low levels of ozone, substantially less than 1.5 ppm, in order to break down into radicals and improve the yield both of the oxidation-reduction and of the cold plasma.

The first and/or the fourth element comprise the above mentioned apparatus.

The process' dynamic begins when the light radiation, having given wavelength, produces photons that strike the semiconductor and create the electron-hole pair.

The holes oxidize the donor molecules (organic substances) or surface hydroxyl groups, giving rise to the oxidant radical ΟΗ·, while the electrons can reduce the acceptor molecules, including oxygen which gives rise to the superoxide radical 0 ₂ · .

These species, which are extremely reactive, in turn can react with other molecules and oxidize them, for example organic compounds.

The chemical process that underlies this is in fact an oxidation/reduction which begins by virtue of the combined action of artificial light, air and humidity.

The two elements, in contact with the coating of the surfaces, in fact favor the activation of the reaction and the consequent breakdown of organic and inorganic substances, of microbes, of nitrogen oxides, of benzene, of sulfur dioxide, of carbon monoxide, of formaldehyde, of methanol, of ethanol, etc. by introducing a thick cloud of ROS (Reactive Oxygen Species) molecules into the air, which purify all the air present in the environment.

The oxidation-reduction reactions, which take place in the irradiated system, are several, but the most interesting are the following:

semiconductor + photons→ e + h ⁺ (1)

e + h ⁺ → heat (2)

e + 0 ₂ →Ο (3)

The generation of the superoxide radical is followed by:

Ο + H ₂ 0→ H0 ₂ + OH (4)

H0 ₂ + e → H0 ₂ (5)

Hydroxyl radicals are generated by this reaction:

OH + h ⁺ → OH ^' (6)

The O 2 can, furthermore, be subjected to the following disproportionation reaction which, overall, can be written as follows:

20 ₂ +2H ⁺ →H ₂ 0 ₂ +0 ₂ ,

while at physiological pH the reaction is broken down into two stages:

a) O ₂ +H ⁺ → H0 ₂ ;

b) H0 ₂ +0 2 +H ⁺ → H ₂ 0 ₂ + 0 ₂ .

For the photocatalytic effect to be effective, it is necessary that the reaction (2) be suppressed or, at least, reduced, so as to favor the reactions (3-6), such that the radicals formed will attack the organic substrate, thus beginning the process of photo-oxidation-reduction, and all this occurs by virtue of the doping of the nanostructured semiconductor (titania) with atoms of silver, copper, gold, rhodium and nickel.

Furthermore, the hydroxyl radical can be produced through the photolysis of water (humidity):

H ₂ 0 + photons = OH ^' + O ^'

The low level of ozone produced (0.04ppm) is broken down (by donating hydrogen to the ozone), thus forming hydroxide ions and radicals, as well as hydroperoxides such as hydrogen and H0 ₂ peroxide radicals:

0 ₃ + e → 0 ₃ - ;

0 ₃ + H ₂ 0→ OH ^" + OH + 0 ₂ ;

0 ₃ + OH → H0 ₂ + 0 ₂ ;

0 ₃ + H0 ₂ → ΌΗ + ΟΓ + 0 ₂

which are desirable reaction products of ozone breakdown owing to their strong oxidant properties, which increase the germicidal effect.

As can be observed, the products of the reaction are in turn ROS molecules, and this means that the ROS trigger oxidation-reduction chain reactions and this increases the damage caused by them to the attacked molecule.

Finally, singlet oxygen (O) is an excited state of molecular oxygen that is formed when the oxygen molecule absorbs a sufficient amount of energy, dispensed by the photons, enabling an inversion of spin of one of the unpaired electrons accompanied by a displacement to a different orbital.

In the oxidation/reduction/ozonizing system, singlet oxygen can be formed starting from the superoxide either by disproportionation, or by the interaction of the superoxide with the hydroxyl radical or with hydrogen peroxide.

Singlet oxygen is considered a strong oxidant since it is capable of reacting with many classes of compounds, for example in particular it oxidizes residues of some amino acids and compounds of chlorine and carbon.

In addition to volatile organic compounds, toxic gases and chemical substances, the oxidation/reduction/ozonizing system renders gases like carbon monoxide and nitrogen oxide harmless. Oxidation of carbon monoxide leads to the formation of carbon dioxide, a substance that is practically inert. The carbon monoxide is oxidized by OH radicals, leading to the formation of hydrogen radicals (H). Such radicals react rapidly with oxygen in the air, forming hydroperoxide radicals: H + 0 ₂ => H0 ₂ . This last radical has much stronger oxidizing properties than the OH radical, such that carbon monoxide could amplify the oxidizing properties of the photocatalytic surface with evident increase of its purifying capacity.

The low-temperature plasma is a partially ionized gas constituted by molecules, molecular fragments, and free radicals with the combined emission of UV rays having an excellent antimicrobial effect, obtained with a special emitter, and it results in the breakage of the bond of the 0 ₂ oxygen molecules and to the formation of free oxygen 0=, which in the gaseous state, being an oxidant, has a highly bactericidal effect.

The ionization of air is obtained with the special emitter which creates the discharge of cold plasma composed of positive and negative ions through the humidity of the air and results in the breakage of the bond of the 0 ₂ oxygen molecules and to the formation of free oxygen 0=, which in the gaseous state, being an oxidant, has a highly bactericidal effect.

The positive and negative ions attack odors and harmful VOCs at molecular level, converting them to harmless atmospheric gases like oxygen, carbon dioxide and water vapor. Finally, the equilibrium of the positive and negative ions neutralizes static electricity discharges.

The emitter complies with healthcare standards with the following levels of ionization of the air: minimum 400 positive and 600 negative airborne ions in one cm ³ of air; maximum 1500-3000 positive and 3000- 5000 negative airborne ions per cm ³ .

In practice it has been found that the invention fully achieves the intended aim and objects by providing a system that is capable of ensuring a complete disinfection and sanitization of the environments. The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Applications No. 102017000017986 (UA2017A001017) and 102017000047911 (UA2017A003101) from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.