The present invention relates to a method and a system for catalytic oxidation of a lean H.sub.2S stream. More specifically, the invention concerns a novel way of removing sulfur dioxide (SO.sub.2) formed by catalytic oxidation of hydrogen sulfide (H.sub.2S) with the purpose of removing H.sub.2S from a gas. This catalytic oxidation of H.sub.2S yields sulfur dioxide (SO.sub.2) through the use of known catalysts, so-called SMC catalysts.

Work area cleanup systems and methods are described for removing tritium from the atmosphere of a work area such as inert gas gloveboxes. Systems utilize a multi-column approach with parallel processing. Tritium of a tritium-contaminated stream is converted into tritiated water and adsorbed onto the separation phase of a first column as a second, parallel column can be simultaneously regenerated. The gaseous stream that exits the column during the regeneration phase can carry a high tritium concentration. The system can also include and a separation stage during which the tritium of the gaseous regeneration stream can be separated from the remainder of the regeneration product.

An integrated mercaptan extraction and/or sweetening and thermal oxidation and flue gas treatment process for a wide variety of sulfur, naphthenic, phenolic/cresylic contaminated waste streams is described. It provides comprehensive treatment for the safe disposal of sulfidic, naphthenic, phenolic/cresylic spent caustic streams, disulfide streams, spent air streams, spent mixed amine and caustic streams (also known as COS solvent streams) from sulfur treating processes. It allows the use of regenerated spent caustic in the sulfur oxide removal section of the thermal oxidation system reducing the need for fresh NaOH. It may also contain an integrated make-up water system. The integration allows the use of the liquefied petroleum gas or other hydrocarbon feeds to the respective extraction or sweetening process to offset external fuel gas requirements for the thermal oxidation system and for the push/pull system of the spent caustic surge drum and optional hydrocarbon surge drum.

A process for combined removal of siloxanes and sulfur-containing compounds from biogas streams, such as streams from landfills or anaerobic digesters, comprises heating the biogas stream and optionally mixing it with air, feeding the gas to a first filter unit with high temperature resistance, injecting a dry sorbent into the first filter unit to capture siloxanes present in the gas, recycling part of the exit gas from the first filter unit to the inlet thereof for the sulfur-containing compounds to be captured by the dry sorbent or optionally to a second filter unit inlet for the sulfur-containing compounds to be captured by a sulfur-specific sorbent and recovering clean gas from the first or optionally from the second filter unit.

A method for treating sulfide in an aqueous fluid comprises contacting the fluid with an oxidizer in the presence of a sulfur dye or sulfurized vat dye. In one embodiment, the method comprises treating sulfide contaminated water by contacting the contaminated water with a gas including oxygen in the presence of a sulfur dye or a sulfurized vat dye. The method is useful for remediating industrial, agricultural, and municipal wastewater.

The invention provides a device and system for decomposing and oxidizing of gaseous pollutants. A novel reaction portion reduces particle formation in fluids during treatment, thereby improving the defect of particle accumulation in a reaction portion. Also, the system includes the device, wherein a modular design enables the system to have the advantage of easy repair and maintenance.

An internal combustion engine includes an engine body, an HC adsorption and removal catalyst in an exhaust, including an HC adsorption layer and a catalyst layer, and having a desorption temperature of the HC from the HC adsorption layer lower than an HC removal temperature of a temperature where a rate of removal of HC at the catalyst layer is a predetermined rate or more when an air-fuel ratio of the exhaust is near the stoichiometric air-fuel ratio, and an air feed device for feeding air to the HC adsorption and removal catalyst. A control device for an internal combustion engine includes an air feed control for controlling feed air to the HC adsorption and removal catalyst when a condition stands. The condition includes the temperature of the HC adsorption and removal catalyst being the desorption temperature or more and less than the HC removal temperature.

The invention provides a device and system for decomposing and oxidizing of gaseous pollutants. A novel reaction portion reduces particle formation in fluids during treatment, thereby improving the defect of particle accumulation in a reaction portion. Also, the system includes the device, wherein a modular design enables the system to have the advantage of easy repair and maintenance.

The invention provides a device and system for decomposing and oxidizing of gaseous pollutants. A novel reaction portion reduces particle formation in fluids during treatment, thereby improving the defect of particle accumulation in a reaction portion. Also, the system includes the device, wherein a modular design enables the system to have the advantage of easy repair and maintenance.

A method for removing hydrogen sulfide from a biogas, wherein the hydrogen sulfide is absorbed in an aqueous liquid to produce a cleaned gas having a reduced amount of hydrogen sulfide relative to the biogas. The aqueous liquid is subsequently treated by contacting with a sulfur dye or sulfurized vat dye in the presence of an oxidizer such as oxygen gas, to convert the sulfides in the aqueous liquid to a non-toxic, water-soluble, product.