A method for decomposing a nitroso compound, comprising: adding an aqueous solution containing hydrogen halide to a liquid to be treated that contains the nitroso compound in such a manner that the hydrogen halide is present in an amount of 2 mol or more and 20 mol or less per mol of a nitroso group in the nitroso compound; and subsequently heating the resulting liquid to be treated at a temperature of not lower that 75° C. and not higher than a boiling point of water under ordinary pressure, thereby an amines are recovered.

A system and method for removing ammonia from an ammonia-containing liquid is described. The system comprises a primary heat exchanger 12 for heating the ammonia-containing liquid to operational temperature, an ammonia stripper 14 for stripping ammonia from the ammonia-containing liquid from the primary heat exchanger and discharging it as ammonia-containing gas, and an acid scrubber 16 for reacting the ammonia in the ammonia-containing gas with acid to form an ammonium salt. The acid scrubber comprises a scrubbed air outlet 32 in fluid communication with a hot air inlet 20 of the ammonia stripper, such that scrubbed air which is discharged from the acid scrubber may be recycled for use in the ammonia stripper. Also described is a system and method for removing ammonia from an ammonia-containing liquid, wherein the system comprises a cold-water scrubber for removing ammonia from the ammonia-containing gas discharged from the ammonia stripper.

A method for removing at least one odorous contaminant from a fluid stream by filtering the fluid stream with a filtration medium. The filtration medium includes a chemically modified activated carbon. The method is useful for removing one or more volatile organic compounds and/or one or more volatile thiol compounds, particularly terpenes (e.g., alpha-pinene and myrcene), nonanol, decanol, o-cymene, and benzaldehyde from the fluid stream. In some embodiments, the fluid stream is a cannabis grow house exhaust stream.

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.

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.

An air pollution control apparatus includes: a denitration unit that removes nitrogen oxides from a flue gas; a desulfurization unit that is installed on a gas flow downstream side of the denitration unit to remove the sulfur oxides in a flue gas 11B; a finish denitration and desulfurization unit that is installed on the gas flow downstream side of the desulfurization unit to perform finish denitration and desulfurization of NO.sub.2 and SO.sub.2; and a carbon dioxide recovery unit that is installed on the gas flow downstream side of the finish denitration and desulfurization unit to remove and recover the carbon dioxide in a flue gas.

A process for purification of waste from zootechnical sources or from small agri-food companies is provided. A plant for carrying out the wastewater treatment process is also provided.

Disclosed are methods and systems for removing submicron particles from a gas stream, in particular from urea prilling off-gas, wherein a Venturi ejector is used. A method comprises contacting a gas stream containing submicron particles in a Venturi ejector with an injected high velocity scrubbing liquid to provide a pumping action, wherein the scrubbing liquid has an initial velocity of at least 25 m/s and wherein the ratio of scrubbing liquid and gas flow is between 0.0005 and 0.0015 (m.sup.3/h)/(m.sup.3/h).

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NO.sub.x, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

Processes and systems for treating Kraft pulping foul condensate are provided. The processes comprise removing volatile compounds from the foul condensate to produce a resulting condensate and removing methanol from the resulting condensate. The systems comprise a volatile compound removal stage and a methanol removal stage downstream of and in fluid communication with the volatile removal stage.