The invention relates to a process for separating off and/or recovering nitrogen compounds, in particular for separating off ammonia and/or recovering or producing nitrogen fertilizer, from a liquid or sludge substrate, in which a liquid or sludge substrate is introduced into a degassing vessel to which subatmospheric pressure is applied and ammonia gas formed is introduced by means of a vacuum pump into at least one scrubber which is located downstream of the degassing vessel and to which subatmospheric pressure is applied and into which acid is introduced, wherein the acid or an ammonium salt-containing liquid obtained in the at least one scrubber is taken off from the at least one scrubber, cooled and subsequently sprayed back into the at least one scrubber. The invention further relates to a plant for carrying out such a process.

The present invention involves a fabrication of a trapezoidal-duct assisting poultry ammonia gas, hydrogen sulfide gas, and dust removal system to be used for removing of the poultry ammonia gas, hydrogen sulfide gas, and dust from the exhausted air stream emitting from the poultry houses and litter storages, comprising a poultry ammonia gas removal tube-screen-scrubber device invented in the present invention, hydrogen sulfide gas adsorber, dust filter, air-speed-acceleration trapezoidal-duct, ventilation-fan, and auxiliary system. The poultry ammonia gas removal tube-screen-scrubber equipped in the poultry ammonia gas removal tube-screen-scrubber device is invented in the present invention using the tube-screen-fill pack patented by the present inventor for use in the water cooling tower. The air-speed-acceleration controller trapezoidal-duct is applied for connecting of the large air outlet cross section of the tube-screen-scrubber device and the small air inlet cross section of the ventilation fan.

The present invention involves a fabrication of a trapezoidal-duct assisting poultry ammonia gas, hydrogen sulfide gas, and dust removal system to be used for removing of the poultry ammonia gas, hydrogen sulfide gas, and dust from the exhausted air stream emitting from the poultry houses and litter storages, comprising a poultry ammonia gas removal tube-screen-scrubber device invented in the present invention, hydrogen sulfide gas adsorber, dust filter, air-speed-acceleration trapezoidal-duct, ventilation-fan, and auxiliary system. The poultry ammonia gas removal tube-screen-scrubber equipped in the poultry ammonia gas removal tube-screen-scrubber device is invented in the present invention using the tube-screen-fill pack patented by the present inventor for use in the water cooling tower. The air-speed-acceleration controller trapezoidal-duct is applied for connecting of the large air outlet cross section of the tube-screen-scrubber device and the small air inlet cross section of the ventilation fan.

This invention relates to a Cu-BTC MOF which is water stable. The Cu-BTC MOF has been modified by substituting some of the BTC ligand (1,3,5, benzene tricarboxylic acid) with 5-aminoisophthalic acid (AIA). The resultant MOF retains at least 40% of its as synthesized surface area after exposure to liquid water at 60° C. for 6 hours. This is an unexpected result versus the MOF containing only the BTC ligand. This MOF can be used to abate contaminants such as ammonia in gas streams and especially air streams.

This invention relates to a Cu-BTC MOF which is water stable. The Cu-BTC MOF has been modified by substituting some of the BTC ligand (1,3,5, benzene tricarboxylic acid) with 5-aminoisophthalic acid (AIA). The resultant MOF retains at least 40% of its as synthesized surface area after exposure to liquid water at 60° C. for 6 hours. This is an unexpected result versus the MOF containing only the BTC ligand. This MOF can be used to abate contaminants such as ammonia in gas streams and especially air streams.

A method for removing ammonia (NH.sub.3) from a gas produced in a pulp mill (100). The method comprises producing raw non-condensable gas comprising ammonia (NH.sub.3) in the pulp mill (100) and transferring at least some of the raw non-condensable gas to a scrubber (200) containing aqueous scrubbing solution (130, 140). The method comprises adding a compound capable of decreasing a pH of the scrubbing solution to the scmbbing solution (130, 140) and in the scrubber (200), contacting the raw non-condensable gas with the scmbbing solution (130, 140), to react the ammonia (NH.sub.3) of the raw non-condensable gas with the scmbbing solution to produce clean non-condensable gas and ammonium (NH.sub.4.sup.+). A pulp mill comprising equipment for performing the method.

A method for removing ammonia (NH.sub.3) from a gas produced in a pulp mill (100). The method comprises producing raw non-condensable gas comprising ammonia (NH.sub.3) in the pulp mill (100) and transferring at least some of the raw non-condensable gas to a scrubber (200) containing aqueous scrubbing solution (130, 140). The method comprises adding a compound capable of decreasing a pH of the scrubbing solution to the scmbbing solution (130, 140) and in the scrubber (200), contacting the raw non-condensable gas with the scmbbing solution (130, 140), to react the ammonia (NH.sub.3) of the raw non-condensable gas with the scmbbing solution to produce clean non-condensable gas and ammonium (NH.sub.4.sup.+). A pulp mill comprising equipment for performing the method.

Disclosed are compositions and methods of ammonia removal in contaminated liquid and gas streams. The compositions may comprise water-soluble phosphonium compounds that react selectively with ammonia at ambient conditions to form covalent compounds. For liquid-phase treatment, the water-soluble phosphonium compounds may be dosed into the contaminated streams followed by pH adjustment using pH elevating compounds to form insoluble compounds. For gas-phase treatment, the water-soluble phosphonium compounds may be used either as scrubbing solution or as solid adsorbent obtained by impregnation into solid substrates to form solid scavengers, to selectively absorb and react with ammonia in a scrubber system.

Disclosed herein is an air cleaner which performs dust collection and sterilization as well as deodorization while having a small size enough to be fitted into a vehicle cup holder for its use, and has a strong and easy maintenance structure. The air cleaner includes a photocatalytic UV LED (57) installed on an UV LED substrate (55), and a photocatalytic filter installed on a surface facing the photocatalytic UV LED while being spaced apart from the UV LED substrate. The photocatalytic filter has a structure in which a photocatalytic material is coated on a base in which a plurality of cells (83) defining an air flow path in a direction toward the photocatalytic UV LED are arranged in parallel adjacent to each other.

The present invention provides processes for filtering undesired chemicals in streams of contaminated air for supply to confined areas. The processes provide (1) contacting air with a filter comprising by volume from about 5% to about 95% impregnated zirconium hydroxide, from about 5% to about 95% activated impregnated carbon, and optionally, up to about 50% ammonia removal material; and (2) supplying the contacted air to a confined area.