Abstract: This invention provides methods for reducing a spark rate and/or increasing the voltage in a cold-side electrostatic precipitator through which a particulate-containing gas stream is directed, wherein said electrostatic precipitator has a spark rate and a voltage. The methods comprise injecting an amount of a halogenated carbonaceous substrate formed from a carbonaceous substrate and an elemental halogen and/or a hydrohalic acid into the particulate-containing gas stream upstream of the electrostatic precipitator, such that the spark rate decreases by about 40% or more and/or such that the voltage can be increased by about 20% or more than when said halogenated carbonaceous substrate is not injected.

Abstract: Mercury adsorbed from combustion gas by activated carbon can be sequestered in concrete containing air entraining admixtures. The activated carbon may be made by providing a carbon char made from anthracite or low-volatile bituminous coal that was devolatilized and carbonized in an oxygen-depleted environment and activating this char in the presence of steam to provide an activated carbon with an acid blue 80 index of less than about 30 milligrams per gram of carbon. The activated carbon may also be made by providing a carbon char that was devolatilized and carbonized in an oxygen-depleted environment and activating this char in the presence of oxygen to provide an activated carbon. The carbon may be injected into a combustion gas stream containing fly ash and mercury and may then be removed with fly ash from the gas stream. The resulting composition may be used as a partial substitute for cement in air-entrained concretes.

Abstract: Mercury adsorbed from combustion gas by activated carbon can be sequestered in concrete containing air-entraining admixtures. The activated carbon may be made by providing a carbon char made from coconut shell, wood, or lignite that was activated by a method selected from the group consisting of activating with steam, activating with CO2, activating in an environment containing free oxygen, and combinations thereof to provide an activated carbon with an Acid Blue 80 Index of less than about 30 milligrams per gram of carbon. The activated carbon may be injected into a combustion gas stream containing fly ash and mercury and may then be removed with fly ash from the gas stream. The resulting composition may be used as a partial substitute for cement in air-entrained concretes.

Abstract: Mercury adsorbed from combustion gas by activated carbon can be sequestered in concrete containing air-entraining admixtures. The activated carbon may be made by providing a carbon char made from coconut shell, wood, or lignite that was activated by a method selected from the group consisting of activating with steam, activating with CO2, activating in an environment containing free oxygen, and combinations thereof to provide an activated carbon with an Acid Blue 80 Index of less than about 30 milligrams per gram of carbon. The activated carbon may be injected into a combustion gas stream containing fly ash and mercury and may then be removed with fly ash from the gas stream. The resulting composition may be used as a partial substitute for cement in air-entrained concretes.

Abstract: Mercury adsorbed from combustion gas by activated carbon can be sequestered in concrete containing air entraining admixtures. The activated carbon may be made by providing a carbon char made from anthracite or low-volatile bituminous coal that was devolatilized and carbonized in an oxygen-depleted environment and activating this char in the presence of steam to provide an activated carbon with an acid blue 80 index of less than about 30 milligrams per gram of carbon. The activated carbon may also be made by providing a carbon char that was devolatilized and carbonized in an oxygen-depleted environment and activating this char in the presence of oxygen to provide an activated carbon. The carbon may be injected into a combustion gas stream containing fly ash and mercury and may then be removed with fly ash from the gas stream. The resulting composition may be used as a partial substitute for cement in air-entrained concretes.

Abstract: A method for removing mercury and mercury-containing compounds from a combustion gas in an exhaust gas system has the steps of providing a mercury sorbent; injecting the mercury sorbent into a stream of the mercury-containing combustion gas for a sufficient time to allow at least an effective amount of the mercury and mercury-containing compounds in the combustion gas to adsorb onto the mercury sorbent, and collecting and removing the mercury sorbent from the combustion gas stream. The mercury sorbent is prepared by treating a carbonaceous substrate with an effective amount of a bromine-containing gas, especially one containing elemental bromine or hydrogen bromide, for a time sufficient to increase the ability of the carbonaceous substrate to adsorb mercury and mercury-containing compounds. The points of injecting and collecting and removing the mercury sorbent may be varied, depending upon the exact configuration of the exhaust gas system.

Abstract: A method for removing mercury and mercury-containing compounds from a combustion gas in an exhaust gas system has the steps of providing a mercury sorbent; injecting the mercury sorbent into a stream of the mercury-containing combustion gas for a sufficient time to allow at least an effective amount of the mercury and mercury-containing compounds in the combustion gas to adsorb onto the mercury sorbent, and collecting and removing the mercury sorbent from the combustion gas stream. The mercury sorbent is prepared by treating a carbonaceous substrate with an effective amount of a bromine-containing gas, especially one containing elemental bromine or hydrogen bromide, for a time sufficient to increase the ability of the carbonaceous substrate to adsorb mercury and mercury-containing compounds. The points of injecting and collecting and removing the mercury sorbent may be varied, depending upon the exact configuration of the exhaust gas system.

Abstract: A method for removing mercury from a combustion gas in an exhaust gas system has the steps of providing a mercury sorbent; injecting the mercury sorbent into a stream of the mercury-containing combustion gas to enable mercury to adsorb onto the sorbent; and collecting and removing the sorbent from the combustion gas stream. The mercury sorbent is prepared by treating a carbonaceous substrate with an ozone-containing gas to increase the ability of the substrate to adsorb mercury. Concrete compositions with fly ash containing the mercury sorbents will have reduced interference with air-entraining-admixtures.

Abstract: A soil amendment for reclaiming mine spoils and for enriching agricultural, horticultural, and turf grass soils while reducing the release of heavy metals into the environment comprising a liming agent, expanded vermiculite or perlite particles, fly ash, and a reaction product generated by exposing a calcium compound in a duct-injection process to a combustion flue-gas stream containing sulfur dioxide.

Abstract: An improved process is described for reducing the levels of nitrogen oxides and carbon monoxide present in flue gases. The process consists of preparing a bed of expanded vermiculite, expanded perlite, or borosilicate glass wool and passing a flue gas containing nitrogen oxides and carbon monoxide through the bed, whereas the vermiculite, perlite, or glass wool making up the bed material serves as a catalyst for the reduction of the nitrogen oxides to gaseous nitrogen and oxygen and the reduction of carbon monoxide to carbon and oxygen, the carbon being deposited on the bed particles. After the deposition of carbon, the bed material is then exposed to an oxidizing gas stream, during which time the deposited carbon is converted to carbon dioxide and the bed material is conditioned to accept flue gas again.

Abstract: A process is disclosed for regenerating spent MgO-vermiculite and MgO-perlite sorbents, where the sorbents have been employed beforehand to remove sulfur and nitrogen oxides from flue gases. The regeneration process consists of a series of heating and cooling steps performed in controlled atmospheres during which time sulfur oxides and elemental sulfur are recovered, nitrogen oxides are destroyed, and the sorbents are returned substantially to their original condition.

Abstract: A process is described for reducing the levels of nitrogen oxides present in flue gases from stationary sources. The process consists of mixing ammonia or methane with the flue gas and then passing the mixtures through a bed of expanded vermiculite, the latter serving as a catalyst for reactions between the nitorgen oxides and ammonia or methane. The reactions result in the formation of nitrogen and water and/or carbon dioxide.

Abstract: A process for absorbing noxious components such as SO.sub.x, NO.sub.x, and HX from a gas such as a flue gas at temperature below 250.degree. C. is improved by contacting the gas with a conditioned solid acceptor that contains divalent metal oxide, hydroxide or both coated onto exfoliated vermiculite and/or expanded perlite. Before use (to enhance its absorption of noxious components) conditioning can be done by heating the hydrated acceptor at temperature of at least about 400.degree. C. for a short time.

Abstract: Solid sorbents (acceptors) for noxious components, e.g. SO.sub.x, NO.sub.x and HX, from gases below about 250.degree., specifically acceptors that contain hydrated divalent metal oxide coated onto an exfoliated or expanded mineral support, are improved by heating them before use at a temperature of 450.degree.-650.degree. for a conditioning period of at least a few minutes. So conditioned pulverulent MgO coated onto water-laden exfoliated vermiculite (alternatively expanded perlite) is preferred because of capacity and the ability of the magnesia-based acceptors to be regenerated at a moderately elevated temperature that precludes substantial deterioration of acceptor or equipment. To insure immediate activity the conditioned acceptor is moistened for use. Advantageously the gas and/or the acceptor is humidified during their contact.

Abstract: A filter is disclosed for treating drinking waters contaminated with lead or, alternately, lead and copper. The filter is made an effective extractor of toxic lead or copper by incorporating a particulate chelating agent having substantial selectivity for lead or lead and copper and having little or no reactivity with all other ions.