Methods of controlling hydrogen sulfide concentration of a biogas occupying an anaerobic membrane bioreactor (AnMBR) containing a submerged membrane are disclosed herein. Methods of controlling dissolved sulfide concentration of a mixed liquor within the AnMBR are disclosed. The methods include directing wastewater containing sulfur and a chemical oxygen demand (COD) to an AnMBR, withdrawing at least a fraction of the biogas from the AnMBR, directing a pre-determined amount of the withdrawn biogas to a scrubber, directing a remainder of the withdrawn biogas to a gas distributor, and directing the scrubbed biogas to the AnMBR. Systems for treating wastewater having sulfur and COD are disclosed. The systems include an AnMBR, a scouring gas closed loop, a scrubber, and a control mechanism for directing biogas to the scrubber and to a gas distributor. Methods of retrofitting a system for treating wastewater having sulfur and COD are disclosed.

A SCR catalyst composition comprises a SCR catalyst; and a binder comprising a porous inorganic material, wherein the porous inorganic material comprises a disordered arrangement of delaminated layers, has a disordered porous structure, and has a multimodal pore size distribution comprising at least a first modal maximum having a macroporous or mesoporous pore size and a second modal maximum having a microporous pore size. The SCR catalyst composition can be manufactured using the method comprising the steps of: (i) providing an inorganic material having a layered structure; (ii) contacting the material with a cationic surfactant to form a swollen material; (iii) agitating the swollen material to form an agitated material; and (iv) calcining the agitated material to recover a delaminated inorganic material, wherein an SCR catalyst is mixed with the inorganic material prior to step (iv).

Provided is a catalytic washcoat having a catalyst component and an alumina binder, wherein the catalyst component includes an aluminosilicate molecular sieve having a beta (BEA) and/or chabazite (CHA) framework, and about 1 to about 10 weight percent of a base metal component comprising iron and/or copper, wherein said weight percent is based on the weight of the aluminosilicate molecular sieve.

A multi-functional composition of matter that is useful for injection into a flue gas stream to rapidly and efficiently remove mercury from the flue gas stream. The multi-functional composition of matter may include a fixed carbon sorbent and minerals, halogens in the form of halide salts, as well as other physical and chemical properties to enhance (1) the oxidation reaction kinetics for the oxidation of mercury species and (2) the mass diffusion kinetics of the mercury species.

The present invention relates to new crystalline zeolite SSZ-52x prepared using a quaternary ammonium cation templating agent, for example, having the structure:

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wherein X.sup.− is an anion which is not detrimental to the formation of the SSZ-52x. SSZ-52x is useful as a catalyst and shows improved durability, particularly with regard to NO.sub.x conversion.

Described are catalytic articles comprising a substrate having a washcoat on the substrate, the washcoat containing a catalytic component having a first average (D50) particle size and a functional binder component having a second average (D50) particle size in the range of about 10 nm to about 1000 nm, wherein the ratio of the first average (D50) particle size to the second average (D50) particle size is greater than about 10:1. The catalytic articles are useful in methods and systems to purify exhaust gas streams from an engine.

A reductant insertion system for an after treatment system configured to decompose constituents of an exhaust gas, includes: a dry reductant tank configured to contain a dry reductant; a reductant delivery line configured to operatively couple the dry reductant tank to the after treatment system for delivery of the dry reductant to the after treatment system; and a pressurized gas source configured to communicate the dry reductant to the after treatment system through the reductant delivery line using pressurized gas.

An exhaust gas treatment device includes a housing having a wall. The wall of the housing defines an interior chamber. A substrate is supported by the housing within the interior chamber of the housing. The substrate extends along a longitudinal axis. The substrate includes a flow through structure that allows the flow of exhaust gas to flow through the substrate. The substrate includes a catalytic composition disposed thereon for reacting with the flow of exhaust gas. The substrate includes a cavity, extending along a cavity axis, which is transverse to the longitudinal axis of the substrate. A sensor is attached to the housing. The sensor includes a probe that at least partially extends into the cavity of the substrate, for sensing a gaseous component in the flow of exhaust gas. The cavity mixes the flow of exhaust gas and directs the exhaust gas toward the probe of the sensor.

A device 2 to remove polar molecules like water vapor from an air stream is provided herein. The device includes a non-conductive housing 4 encapsulating a chamber 5 where the chamber 5 includes a fan 6 located at one end of the chamber 5 which allows air 24 to enter into the chamber 5, at least one metallic brush 12 is located inside a chamber and mounted on a dielectric holder 14, a curved solid wall 39 integrated with the non-conductive housing 4 at one end where the curved solid wall 39 allows smooth passage of air flow 24 from the chamber 5 and ensures minimum impingement on the brush 12, a curved wire mesh 40 integrated with the non-conductive housing 4 at the other end opposite to the curved solid wall 39, a power supply 18 to charge the metallic brush 12 and the curved wire mesh 40, where the metallic brush 12 when charged ionizes the air 24 to produce the ion current 26, facilitating removal of polar molecules from the air 24 to generate purified air 42 from the device 2.

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Jr and Pt.