A long-effect self-cleaning negative-pressure ejector at least comprises a suction chamber, a jet pipe and a flushing member. A side wall of the suction chamber has at least one suction port for communicating with a first fluid pipeline. An exit port of the jet pipe is disposed in the suction chamber and ejects a second fluid so that a negative pressure is generated in the suction chamber, a first fluid in the first fluid pipeline obliquely enters the suction chamber, and a first included angle is between a direction in which the first fluid being sucked into the suction chamber and an ejection direction of the second fluid. The flushing member optionally provides a third fluid to flush the suction chamber and/or the first fluid pipeline. At least one air jet nozzle is disposed on the first fluid pipeline to inject gas into the first fluid pipeline.

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

A wet scrubber at least comprises a treatment tank, a jet pipe, a gas-liquid separation component, and a spray component. The treatment tank is used to contain a cleaning solution. The jet pipe is disposed in the treatment tank, by injecting the cleaning solution to suck in an exhaust gas, and mixing the cleaning solution with the exhaust gas, and directly injecting into the cleaning solution contained in the treatment tank, thereby forming a plurality of microbubbles in the cleaning solution to dissolve the exhaust gas and capture solid particles in the exhaust gas. The gas-liquid separation component is used to filter and block water mist raised in the cleaning solution. The spray component is used to prevent the solid particles from clogging the gas-liquid separation component.

A system for removing undesirable compounds from contaminated air includes a biofilter having an alkaline material introduction system and a fuzzy-logic based controller. A contaminant, such as hydrogen sulfide, is removed from contaminated air by passing the contaminated air through the biofilter.

A process is provided using a concentrated sodium bicarbonate solution as a solubilizer mixed with a calcium hydroxide to chemically produce an insoluble calcium carbonate and produce an alkaline liquid solution, then passing the alkaline liquid solution through detrimental gases in a scrubber to produce an enhanced sodium bicarbonate which regenerates the sodium bicarbonate thus creating a continuous closed loop. The process can also produce a sodium phosphate (trisodium phosphate) by mixing the alkaline liquid solution with a phosphoric acid.

Disclosed is a method for fast and cost-efficient preparation of ikaite crystals. The method comprises contacting an alkaline aqueous solution, which comprises carbonate and bicarbonate ions, with a water solution, which comprises Ca.sup.2+, at a temperature not exceeding 15° C., wherein contact between the alkaline aqueous solution and the water solution takes place at a permeable or porous surface, through which either solution is fed to the other at a flow rate facilitating formation of ikaite crystals. Also disclosed is system for carrying out the ikaite preparation process. The process and system provides a cost efficient and effective means for capture and storage of carbon dioxide.

A method for preparing hydrogen sulfide from sulfur dioxide by electrochemical reduction includes electrochemically reducing sulfur dioxide absorbed in an aqueous solution into gaseous hydrogen sulfide with a membrane electrode, resulting in efficient and selective conversion of the sulfur dioxide absorbed in the aqueous solution into the hydrogen sulfide to avoid a deactivation of a cathode due to colloidal sulfur produced on the cathode and adhesion onto a surface of the cathode, wherein the method is carried out at ambient temperature and normal pressure without addition of a reducing agent, having no waste salts produced, and is simple in operation, and is convenient for large-scale application.

The present invention is directed to the removal of mercury from a gas phase by injecting a scavenger solution into the gas phase.

In accordance with one aspect of the presently disclosed inventive concepts, a porous ceramic structure includes a three-dimensional printed structure having predefined features, where the three-dimensional structure has a geometric shape. The average length of the features may be at least 10 microns. The three-dimensional structure includes a ceramic material having an open cell structure with a plurality of pores, where the pores form continuous channels through the ceramic material from one side of the ceramic material to an opposite side of the ceramic material.