KR20020028971A - Apparatus for sterilization of nosocomial airborne infectious bacteria/fungus by non-thermal plasma combined electro-oxidation catalysis. - Google Patents

Abstract

PURPOSE: Provided is an apparatus for sterilizing air-mediated infectious bacteria in hospitals by non-heating plasma using an oxidizing semiconductor catalyst electrode, whereby it is possible to safely and rapidly treat bacteria in the hospitals without secondary air contamination. CONSTITUTION: The apparatus comprises a dust collecting part as a pretreatment filter for filtering dusts in the rooms and a non-heating plasma part for generating plasma. The non-heating plasma part is provided with a UV lamp having a wavelength of 260 to 280 nm to excite bacteria. The bacteria excited by the UV lamp are attached to surfaces of the oxidizing semiconductor catalyst. On the catalyst surface, the bacteria are killed by high voltage impact. Also, electrons or pores separated from the catalyst surface by electric energy generate hydroxy radicals, which penetrate into bacteria to destroy them. The oxidizing semiconductor catalyst electrode has a composition of T-M-MO, in which T is titanium dioxide, M is a metal such as titanium, silver, vanadium, cobalt, copper, platinum, and MO is an oxide of a metal such as silver, vanadium, cobalt, and copper.

Description

Apparatus for sterilization of nosocomial airborne infectious bacteria / fungus by non-thermal plasma combined electro-oxidation catalysis.}

The present invention relates to a non-heated plasma apparatus for sterilizing Gram-negative bacillus and Staphylococcus aureus, which are airborne infectious bacteria in a hospital, manufactured by an oxidative semiconductor catalyst electrode. It is intended to provide a device that sterilizes quickly and is free of secondary pollutants.

Chemical sterilization and physical sterilization have been applied to sterilize airborne infectious agents in hospitals. The chemical sterilization method mainly uses formarin gas sterilization and ethylene oxide gas sterilization, but formarin is a residual toxic substance that is irritating to skin and eyes and may cause secondary air pollution when released to the atmosphere. Ethylene oxide gas also causes skin damage, mucous membrane irritation, hemolysis, and secondary air pollution. All of these chemical sterilization methods have to be isolated and transported to a safe place for gas sterilization due to residual toxicity, and it is difficult to apply them in a hospital because there are problems to close the sterilization area thoroughly.

In addition, there is a sterilization method by electron beam irradiation in the physical sterilization method, but the sterilization part is extremely limited, and the price of equipment is expensive, so it is not suitable for practical application.

SUMMARY OF THE INVENTION The present invention has been made to solve such drawbacks, by using an oxidative semiconductor catalyst electrode and a high voltage pulse power source as an energy source for plasma generation, and by using an ultraviolet lamp having a wavelength of 260 to 280 nm in parallel. Its purpose is to sterilize my airborne infectious organisms.

〈Means for solving the problem〉

The basic structure of the present invention is composed of a dust collecting unit as a pre-treatment filter for filtering out fine dust in the room, an ultraviolet lamp unit, and a non-heating plasma unit for generating plasma.

The bacterium is composed of a protoplast surrounded by a bacterial spore membrane as a basic structure (Fig. 1). These bacteria are closely related to water, so they multiply in a watery environment, and the protoplasm contains 65 to 90% water. The basic principle of the present invention is based on sterilizing bacteria using this water.

The basic action of oxidative semiconductor catalysts is the generation of electrons and holes by electrical energy, the transfer and charge separation of electrons and holes to the surface, the generation of surface active species trapped in electrons and holes, and the reaction by these active species Consisting of intermediate and final products.

In addition, pathogens undergo adsorption, decomposition, and desorption on the surface of the oxidative semiconductor catalyst.

So from an electrochemical perspective

First, bacteria excited by the electron beam of the ultraviolet lamp are adsorbed on the surface of the oxidative semiconductor catalyst,

Second, the adsorbed bacteria are destroyed by bacterial spore membranes by alternating 15-30kV and pulsed power 10-20kV.

Third, moisture in the inner plasma is destroyed by high voltage electrons and pulse shock waves due to spore film destruction.

In terms of catalysis, it can be divided into the action on the moisture in the air.

The catalyst surface electric energy + → e ^{- +} h +

h ⁺ + H ₂ O → · OH + H ⁺

(e ^-, h ^+: The electrons and holes are separated on the surface of the catalyst by electric energy)

Here, OH radical is an active species with strong bactericidal power and has a function of penetrating and sterilizing the spore membrane of bacteria.

Next, look at the water in the plasma through the spore film destroyed by the high-voltage electric shock

h ⁺ + H ₂ O → · OH + H ⁺

As to cause the same action.

Looking at all of the above

Bacteria + Ultraviolet Lamp → Excited Bacteria (1)

Excited Bacteria + High Voltage Shock → Cellular Destruction and Plasma Sterilization (2)

h ⁺ -H ₂ O (moisture in air) → OH + H ⁺ (3)

h ⁺ + H ₂ O (moisture in the protoplasm) → OH + H ⁺ (4)

Bacterial Protoplasts + OH → Bacterial Sterilization (5)

Fast sterilization is performed through the same process.

<< Example >>

<Production of Oxidative Semiconductor Catalyst Electrode>

Titanium alkoxide is mixed with two solutions with a 5 wt% aqueous sulfuric acid solution / alkoxide molar ratio of 50, followed by stirring for 2-3 hours to cause a hydrolysis reaction. Based on 100 g of the obtained orthotitanic acid, 20-30 g of 4 wt% aqueous lithium hydroxide solution, 1.5-3.0 g of methanol, and 5-15 g of 1 wt% chloroplatinic acid were mixed and stirred for 1 to 5 hours under high pressure mercury lamp irradiation. . Then, 5 to 10 g of bismuth oxide was mixed and stirred for 1 to 5 hours, and then 5 to 40 g of silver iodide or potassium iodide dissolved in 20% to 25 wt% in 10% aqueous ammonia was added, and vanadium pentoxide, tungsten trioxide, and molybdenum trioxide were added thereto. 1 to 5 g of each, 5 to 25 g of manganese dioxide, 10 to 40 g of copper oxide, and 1 to 2 g of cobalt oxide were added, followed by final stirring for 2 to 8 hours.

The dispersion-finished semiconductor composition is coated on a stainless mesh or stainless mat or nickel sintered mat and then calcined at 350 to 500 ° C. for 6 to 12 hours to obtain a final oxidative semiconductor catalyst electrode.

1 is a bacterial cell spore permeability of nutrients, fungicides, etc.

Figure 2 is a basic layout of the sterilization device (mobile type)

3 is a test result according to the embodiment

<Explanation of symbols for main parts of the drawings>

(1) pretreatment dust collecting filter

(2) UV lamp

(3) Oxidative Semiconductor Catalyst Electrode

(4) exhaust fan

.

As described above, the present invention forms electron-holes on the surface of an oxidative semiconductor by electric energy and sterilizes bacteria by high field, thereby safely and quickly treating bacteria in a hospital room without secondary air pollution. As a device, the secondary infection can be minimized by sterilizing airborne infectious agents in the hospital.

Claims (3)

A structure that installs an ultraviolet lamp with a wavelength of 260-280nm to excite bacteria. In the method for producing an oxidative semiconductor catalyst electrode, having the following structural formula T-M-MO Here, T is titanium dioxide and M is a metal, which corresponds to titanium, silver, vanadium, cobalt, copper, and platinum, and MO is a metal oxide, which corresponds to silver oxide, vanadium pentoxide, cobalt oxide, and copper oxide. Oxidative semiconductor catalyst electrode. An apparatus for sterilizing airborne infectious bacteria in a hospital by applying an alternating current 15-30 kV and a pulse power supply 10-20 kV to an oxidative semiconductor catalyst electrode and an unheated plasma part.