The present invention relates to an air treatment method and a system (1a-1f) arranged for treating an air flow (3) to be entered into a semiconductor clean room. Said air flow (3) comprises at least one vapour phase compound, and wherein the air flow (3) is subjected to at least one first treatment process arranged for reducing the concentration of the at least one vapour phase compound in the treated air flow below a predefined threshold, and wherein said first treatment process comprises subjecting the air flow to at least one photooxidation step.

A device for testing performance of photocatalytic ozonation in degradation of volatile organic compounds. The device includes an air generator, an oxygen cylinder, a volatile organic compound cylinder, a mass flow meter, an ozone generator, a humidifier, a thermohygrometer, a gas mixer, a light source, a plate-type reactor, an ozone analyzer, a gas chromatographic instrument, a first valve, a second valve, a third valve and a tail gas treatment unit; The experimental device of the present invention is suitable for the experiment of photocatalytic degradation of volatile organic gases in mixed gas, and has the advantages of wide experimental conditions, simple structure, convenient use, reliable performance, etc.

An exhaust dust removal system includes an electric field device (1021) and a cooling device. The electric field device (1021) has an electric field device inlet, an electric field device outlet, a dust removal electric field cathode (10212), and a dust removal electric field anode (10211). The dust removal electric field cathode (10212) and the dust removal electric field anode (10211) are used to generate an ionizing dust removal electric field. The cooling device is used to reduce the exhaust temperature before the electric field device inlet. The exhaust dust removal system may help reduce greenhouse gas emissions, and may also help reduce emissions of harmful gases and pollutants, which thereby makes the gas emissions more environmentally friendly.

Systems and methods for producing nitrates, nitric acid, salts thereof, or a mixture thereof are disclosed. The systems may include a feed conduit configured for receiving a feed stream comprising molecular oxygen and molecular nitrogen; an inlet conduit configured for receiving an inlet stream; a plasma reactor fluidically coupled to the inlet conduit, the plasma reactor fluidically coupled to a reactor-outlet conduit configured for receiving the reactor-outlet stream, the plasma reactor configured to produce oxidized nitrogen species; and an absorber fluidically coupled to the reactor-outlet conduit, the absorber configured to receive the reactor outlet stream and to produce nitrates, nitrites, nitric acid, salts thereof, or a mixture thereof from the reactor outlet stream. A recycle conduit may be fluidically coupled to the absorber and the inlet conduit, wherein the recycle conduit is configured to receive the gas-phase stream from the absorber and provide the gas-phase stream to the inlet conduit.

An engine tail gas ozone purifying system and method. The engine tail gas ozone purifying system comprises reaction fields (220, 202) used for mixture reaction of an ozone stream and a tail gas stream. A large amount of urea does not need to be added and the purification effect is good.

An exhaust gas dust removal system, comprising a dust removal system inlet, a dust removal system outlet and an electric field apparatus, the electric field apparatus comprising an electric field apparatus inlet, an electric field apparatus outlet, a dust removal electric field cathode and a dust removal electric field anode, the dust removal electric field cathode and the dust removal electric field anode being used for producing an ionising dust removal electric field. A dust collection area of the dust removal electric field anode is larger than a discharge area of the dust removal electric field cathode, so that an asymmetric electrode attraction force is produced between the electrodes, to reduce electric field couplings.

An engine exhaust gas ozone purification method, comprising: mixing a ozone stream and an exhaust stream to react, and removing nitric acid in a reaction product of the ozone stream and the exhaust stream mixture. A gas that has a nitric acid mist is caused to flow through a first electrode (301). When the gas that has the nitric acid mist flows through the first electrode (301), the first electrode (301) charges the nitric acid mist in the gas, and a second electrode (302) applies an attractive force to the charged nitric acid mist, so that the nitric acid mist is moved toward the second electrode (302) until the nitric acid mist adheres onto the second electrode (302). The present engine exhaust gas ozone purification method does not need to add a large amount of urea, and the purification effect is good.

A system and method for purifying engine exhaust by using ozone; the system for purifying engine exhaust by using ozone comprises a reaction field (202), which is used to mix an ozone stream and an exhaust stream for reaction; the system has an excellent purification effect without needing to add a large amount of urea.

An exhaust gas ozone purification method, specifically comprising: enabling a mixing reaction between an ozone stream and an exhaust gas stream, and removing nitric acid from mixed reaction products between the ozone stream and the exhaust gas stream by using an electrocoagulation device. The electrocoagulation device comprises: a first electrode (301) electrifying water spray of nitric acid; and a second electrode (302) applying an attraction force to the electrified water spray. The method can realize the purification of exhaust gas.

An exhaust gas ozone purification method, specifically comprising: enabling a mixing reaction between an ozone stream and an exhaust gas stream, and removing nitric acid from mixed reaction products between the ozone stream and the exhaust gas stream by using an electrocoagulation device. The electrocoagulation device comprises: a first electrode (301) electrifying water spray of nitric acid; and a second electrode (302) applying an attraction force to the electrified water spray. The method can realize the purification of exhaust gas.