The invention relates to a method for nitrogen removal from aqueous medium, comprising steps of (a) converting NH.sub.4.sup.+ in the aqueous medium to NO.sub.2.sup.− by partial aerobic nitrification, (b) partially reducing the obtained NO.sub.2.sup.− to N.sub.2O in anoxic conditions, and (c) decomposing N.sub.2O to N.sub.2 with energy recovery. A mixture of ferrous sulfate and ferric sulfate is used in step (b) for reduction of NO.sub.2.sup.− to N.sub.2O.

The present invention is an ammonia sequestering system including a system controller connected to a plurality of flow control valves, a feed stream extending through a system inlet, and a system outlet. The feed stream is a liquid contaminated with ammonia. At least one exchange column is located between the system inlet and the system outlet. The ion column includes an ion exchange material, a column inlet connected to one of the flow control valves, and a column outlet connected to another of the flow control valves. The system also includes a regenerant stream of an aqueous solution of sodium cations, as well as an ammonia brine stream made up of the regenerant stream and ammonia.

The present invention is an ammonia sequestering system including a system controller connected to a plurality of flow control valves, a feed stream extending through a system inlet, and a system outlet. The feed stream is a liquid contaminated with ammonia. At least one exchange column is located between the system inlet and the system outlet. The ion column includes an ion exchange material, a column inlet connected to one of the flow control valves, and a column outlet connected to another of the flow control valves. The system also includes a regenerant stream of an aqueous solution of sodium cations, as well as an ammonia brine stream made up of the regenerant stream and ammonia.

This invention relates to a method and apparatus for recycling plastics, electronics, munitions or propellants. In particular, the method comprises reacting a feed stock with a molten aluminum or aluminum alloy bath. The apparatus includes a reaction vessel for carrying out the reaction, as well as other equipment necessary for capturing and removing the reaction products. Further, the process can be used to cogenerate electricity using the excess heat generated by the process.

This invention relates to a method and apparatus for recycling plastics, electronics, munitions or propellants. In particular, the method comprises reacting a feed stock with a molten aluminum or aluminum alloy bath. The apparatus includes a reaction vessel for carrying out the reaction, as well as other equipment necessary for capturing and removing the reaction products. Further, the process can be used to cogenerate electricity using the excess heat generated by the process.

A nitric acid production process, comprising tertiary abatement of N2O and NOx on a tail gas withdrawn from an absorption stage, said abatement including passing the tail gas over a sequence of a deN2O stage comprising a Fe-z catalyst and a deNOx stage comprising a V2O5-TiO2 catalyst in the presence of gaseous ammonia, wherein the tail gas at the inlet of deN2O stage and the tail gas at the inlet of deNOx stage have a temperature greater than 400° C.

A process and apparatus for managing hydrogen sulfide in a refinery is provided. In the process, a hydrogen sulfide stream from said refinery is fed to a sulfur recovery unit to produce sulfur and a sulfur compound stream or to a thermal oxidizer. The sulfur compound stream and the hydrogen sulfide stream are then thermally oxidized to produce a sulfur oxide stream. The sulfur oxide stream is then reacted with an ammonia stream. In aspect, the product of the reaction can be a fertilizer. The ammonia stream can be obtained from stripping the hydrogen sulfide stream.

A process and apparatus for managing hydrogen sulfide in a refinery is provided. In the process, a hydrogen sulfide stream from said refinery is fed to a sulfur recovery unit to produce sulfur and a sulfur compound stream or to a thermal oxidizer. The sulfur compound stream and the hydrogen sulfide stream are then thermally oxidized to produce a sulfur oxide stream. The sulfur oxide stream is then reacted with an ammonia stream. In aspect, the product of the reaction can be a fertilizer. The ammonia stream can be obtained from stripping the hydrogen sulfide stream.

Provided is at least one of an improvement in the thermal stability of a CHA-type zeolite, which is achieved by a method different from that of the related art for improving thermal stability; a method for producing a CHA-type zeolite that improves thermal stability; and such a CHA-type zeolite. Provided is a CHA-type zeolite having a .sup.1H-MAS-NMR spectrum and an IR spectrum in which, preferably, in the .sup.1H-MAS-NMR spectrum, a ratio of an integrated intensity of a maximum peak having a peak top at a chemical shift of 3.0 to 3.5 ppm to an integrated intensity of a maximum peak having a peak top at a chemical shift of 4.0 to 4.5 ppm is greater than 0.12 and 0.5 or less, and, in the IR spectrum, a ratio of a maximum peak height of an absorption peak having a peak top at a wavenumber of 3630 cm.sup.−1 or greater and 3650 cm.sup.−1 or less to a maximum peak height of an absorption peak having a peak top at a wavenumber of 3590 cm.sup.−1 or greater and 3610 cm.sup.−1 or less is 0.40 or greater and 1.0 or less.

Provided is at least one of an improvement in the thermal stability of a CHA-type zeolite, which is achieved by a method different from that of the related art for improving thermal stability; a method for producing a CHA-type zeolite that improves thermal stability; and such a CHA-type zeolite. Provided is a CHA-type zeolite having a .sup.1H-MAS-NMR spectrum and an IR spectrum in which, preferably, in the .sup.1H-MAS-NMR spectrum, a ratio of an integrated intensity of a maximum peak having a peak top at a chemical shift of 3.0 to 3.5 ppm to an integrated intensity of a maximum peak having a peak top at a chemical shift of 4.0 to 4.5 ppm is greater than 0.12 and 0.5 or less, and, in the IR spectrum, a ratio of a maximum peak height of an absorption peak having a peak top at a wavenumber of 3630 cm.sup.−1 or greater and 3650 cm.sup.−1 or less to a maximum peak height of an absorption peak having a peak top at a wavenumber of 3590 cm.sup.−1 or greater and 3610 cm.sup.−1 or less is 0.40 or greater and 1.0 or less.