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 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: 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 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.