There are provided methods for treating a gas having an undesirable odor. The methods comprise contacting the gas with an acidic aqueous oxidizing composition having a pH of about 2.0 to about 3.0 and comprising at least one cation of a metal; a sequestering agent; and H.sub.2O.sub.2 and submitting the gas and the composition to UV radiation when the gas and the composition are contacting each other, wherein the treatment permits to reduce by at least 60% intensity of the undesirable odor.

Methods and systems for capturing and storing carbon dioxide are disclosed. In some embodiments, the methods include the following: mixing materials including magnesium or calcium with one or more acids and chelating agents to form a magnesium or calcium-rich solvent; using the organic acids derived from biogenic wastes as acids or chelating agents; generating carbonate ions by reacting a gas including carbon dioxide with a carbonic anhydrase biocatalyst; reacting the solvent with the carbonate ions to form magnesium or calcium carbonates; recycling a solution containing the biocatalyst after forming magnesium or calcium carbonates for re-use in the generating step; using the magnesium and calcium carbonates as carbon neutral filler materials and using the silica product as green filler materials or inexpensive absorbents.

There are provided methods for treating a gas having an undesirable odor. The methods comprise contacting the gas with a basic aqueous oxidizing composition having a pH of about 9.0 to about 10.0 and comprising H.sub.2O.sub.2 at a concentration of about 20 mg/L to about 700 mg/L, and submitting the gas and the composition to UV radiation when the gas and the composition are contacting each other, wherein the treatment permits to reduce by at least 60% intensity of the undesirable odor.

A method for removing SO.sub.x from a gas by using a polyol composite solution is provided. The polyol composite solution is made by mixing a polyol with an organic acid and/or organic acid salt, the polyol composite solution is brought into contact with the gas containing SO.sub.x to absorb the SO.sub.x in the gas, wherein x=2 and/or 3, and the polyol refers to an organic compound other than ethylene glycol and polyethylene glycol, which contains simultaneously two or more than two hydroxyl groups in a same organic molecule.

The present invention describes a fluid which is suitable for the decontamination of heat engines which can carry out both, at the same time, the catalytic reduction of oxides of nitrogen (NOx) contained in exhaust gases and assist in the regeneration of the particulate filter (PF). The invention also describes several embodiments of said fluid.

Solutions of carbon nanotubes and methods for purifying the solutions are provided. The methods include mixing, for example, at least one complexing agents, at least one ionic species, and/or at least one buffer oxide etch (BOE) with a liquid medium containing carbon nanotubes and different types of contaminants, such as metal impurities, amorphous carbon, and/or silica particles, and performing a filtration process to the liquid medium so as to remove or reduce the contaminants in the liquid medium. As a result, carbon nanotube solutions of low contaminants are produced. In some embodiments, the solutions of this disclosure include a high concentration of carbon nanotubes and are substantially free from metal, amorphous carbon, and/or silica impurities.

The present invention relates to an electrolysis apparatus for collecting a nitrogen compound using ferric-ethylenediaminetetraacetic acid (Fe-EDTA), and more particularly, to an electrolysis apparatus for collecting a nitrogen compound in exhaust gas by supplying electric energy to cause a redox reaction of Fe-EDTA.

Waste treatment comprises heating it in a chamber to effect pyrolysis of the waste, introducing oxygen into the chamber to effect combustion of the pyrolyzed waste, and contacting off-gas from the pyrolysis and/or combustion steps with an oxidation catalyst to convert carbon monoxide and hydrocarbons in the off-gas into carbon dioxide and water and with a reduction catalyst to convert nitrous oxides to nitrogen and oxygen. Thus, domestic waste is treated in a batch process using catalytic converters to reduce the level of toxic components before off-gas reaches the atmosphere.

Waste treatment comprises heating it in a chamber to effect pyrolysis of the waste, introducing oxygen into the chamber to effect combustion of the pyrolyzed waste, and contacting off-gas from the pyrolysis and/or combustion steps with an oxidation catalyst to convert carbon monoxide and hydrocarbons in the off-gas into carbon dioxide and water and with a reduction catalyst to convert nitrous oxides to nitrogen and oxygen. Thus, domestic waste is treated in a batch process using catalytic converters to reduce the level of toxic components before off-gas reaches the atmosphere.

Waste treatment comprises heating it in a chamber to effect pyrolysis of the waste, introducing oxygen into the chamber to effect combustion of the pyrolyzed waste, and contacting off-gas from the pyrolysis and/or combustion steps with an oxidation catalyst to convert carbon monoxide and hydrocarbons in the off-gas into carbon dioxide and water and with a reduction catalyst to convert nitrous oxides to nitrogen and oxygen. Thus, domestic waste is treated in a batch process using catalytic converters to reduce the level of toxic components before off-gas reaches the atmosphere.