A system for resource recycling of sulfur dioxide includes a charcoal reduction furnace, a high temperature dust remover, a cooling separator A, a liquid sulfur tank, a cooling separator, a tail gas absorption tower, a gas stripping tower, a hypo reactor, a centrifuge, a mother liquor tank and a thickener. And a method for resource recycling of sulfur dioxide includes the following steps: (1) preparing elemental sulfur, (2) removing dust from a process gas containing gaseous sulfur, (3) separating elemental sulfur, (4) reabsorbing residual SO.sub.2 gas, (5) purifying sulfur powder, (6) preparing a slurry of cured hypo, (7) performing liquid-solid separation, and (8) preparing an absorption slurry. According to the method, SO.sub.2 gas is reduced into liquid sulfur and sulfur powder, and sodium thiosulfate is coproduced.

The invention pertains to methods of reducing dissolved elements such as arsenic, selenium and mercury in aqueous solutions using, for example, various barium compounds to partition said elements to a solid phase. Such methods are particularly useful for reducing such elements at various points in coal and oil-fired power plants prior to final waste water treatment.

An ammonia-based multi-zone double-loop process for ultra-low emission of multi-pollutant. From an absorption tower inlet, the flue gas successively passes through cooling concentration crystallization, sulfur oxide absorption, water washing and purifying and dust and mist removing zones, which are separated by gas permeable liquid collecting plates, forming clean flue gas and discharged from an outlet. The cooling concentration crystallization zone, the sulfur oxide absorption zone, and the water washing and purifying zone are respectively provided with a plurality of sprayers, and respectively use a concentration liquid, an absorption liquid, and a water washing liquid as spraying liquids. The absorption, concentration and water washing liquids, after converging respectively, into absorption, concentration crystallization and water washing circulation tanks, the absorption, concentration and water washing liquids, respectively, are sprayed in a circulating manner through absorption, concentration and water washing pumps.

A method for simultaneously removing high-load sulfur dioxide and nitrogen oxide in waste gas, relating to the technical field of industrial waste gas purification by biological methods. According to the method, the waste gas is led into a simultaneous desulfurization and denitrification packing tower and removed, microbial floras for simultaneously removing the sulfur dioxide and the nitrogen oxide are loaded on fillers of the packing tower, and the molar concentration ratio of the sulfur dioxide to the nitrogen oxide in the waste gas is (0.76˜1.06):1.

Controlling aerosol production during absorption in ammonia-based desulfurization. The absorption reaction temperature, the oxygen content and water content of the process gas may be controlled, and an absorption circulating liquid containing ammonium sulfite may be used for removing sulfur dioxide in flue gas, so as to control aerosol production during absorption in the ammonia-based desulfurization.

Some embodiments of the present disclosure relate to a method of regenerating at least one filter medium comprising: providing at least one filter medium, wherein the at least one filter medium comprises: at least one catalyst material; and ammonium bisulfate (ABS) deposits, ammonium sulfate (AS) deposits, or any combination thereof; flowing a flue gas stream transverse to a cross-section of a filter medium, such that the flue gas stream passes through the cross section of the at least one filter medium, wherein the flue gas stream comprises: NOx compounds comprising: Nitric Oxide (NO), and Nitrogen Dioxide (NO.sub.2); and increasing an NOx removal efficiency of the at least one filter medium after removal of deposits.

An apparatus for converting a toxic gas to benign substances comprises a housing characterized with multi-stages including a first stage, a second stage, a third stage and a fourth stage coupled to one another in sequence, wherein the first stage comprises a catalytic system configured to convert the toxic gas into its derivatives; the second stage comprises a carbonaceous fibrous material adapted to capture the remaining toxic gas and the derivatives; the third stage comprises at least one oxidizer to oxidize the remaining toxic gas to benign substances including CO.sub.2 and water; and the fourth stage comprises a scrubber configured to remove all of volatile organic compounds or water molecules generated as part of the first and third stages.

In a system and process, organic waste is treated in a reactor to volatilize contaminants such as Perfluoroalkyl substances (PFAS) compounds and/or Contaminants of Emerging Concern (CECs) from the organic waste. Biochar may have reduced or undetectable PFAS compounds or CECs. Most or all of the gas may be thermally oxidized to convert PFAS compounds and/or CECs into less harmful and/or less toxic products or elemental compounds, which may be further removed. Energy may be recovered from one or more parts of the herein described system and process.

An exhaust aftertreatment system for increasing fractional efficiency of diesel or gasoline particulate filters includes a particulate filter that includes a housing and a filter substrate positioned in the housing. The filter substrate is pre-conditioned with an aqueous solution or suspension configured to decompose or evaporate in response to exposure to heat so as to precondition the filter substrate.

An exhaust aftertreatment system for increasing fractional efficiency of diesel or gasoline particulate filters includes a particulate filter that includes a housing and a filter substrate positioned in the housing. The filter substrate is pre-conditioned with an aqueous solution or suspension configured to decompose or evaporate in response to exposure to heat so as to precondition the filter substrate.