The present application provides a waste water preconditioning system for limiting mercury concentrations in a waste water stream resulting from treatment of a flue gas. The waste water preconditioning system may include a wet flue gas desulfurization system for treating the flue gas with an aqueous alkaline slurry, a sulfite detector to determine the concentration of sulfite in the aqueous alkaline slurry, and to produce the waste water stream with a mercury concentration of less than about five micrograms per liter. The waste water preconditioning system also may include a waste water treatment system downstream of the wet flue gas desulfurization system.

The present application provides a waste water preconditioning system for limiting mercury concentrations in a waste water stream resulting from treatment of a flue gas. The waste water preconditioning system may include a wet flue gas desulfurization system for treating the flue gas with an aqueous alkaline slurry, a sulfite detector to determine the concentration of sulfite in the aqueous alkaline slurry, and to produce the waste water stream with a mercury concentration of less than about five micrograms per liter. The waste water preconditioning system also may include a waste water treatment system downstream of the wet flue gas desulfurization system.

A method for production of ammonium phosphate from phosphate rock slurry. The method includes: introducing flue gas containing SO.sub.2 into a phosphate rock slurry, to yield an absorption solution; evaporating waste ammonia water containing 10-20 wt. % ammonia to yield ammonia gas; introducing the ammonia gas into the absorption solution at a temperature of 110-135° C. until a neutralization degree of the absorption solution reaches 1.5-1.6, thus yielding an ammonium phosphate solution and calcium sulfate; separating the calcium sulfate from the ammonium phosphate solution; and introducing the ammonium phosphate solution to a granulator for granulation to yield ammonium phosphate granules; drying and sieving the ammonium phosphate granules, thereby yielding ammonium phosphate.

A method for production of ammonium phosphate from phosphate rock slurry. The method includes: introducing flue gas containing SO.sub.2 into a phosphate rock slurry, to yield an absorption solution; evaporating waste ammonia water containing 10-20 wt. % ammonia to yield ammonia gas; introducing the ammonia gas into the absorption solution at a temperature of 110-135° C. until a neutralization degree of the absorption solution reaches 1.5-1.6, thus yielding an ammonium phosphate solution and calcium sulfate; separating the calcium sulfate from the ammonium phosphate solution; and introducing the ammonium phosphate solution to a granulator for granulation to yield ammonium phosphate granules; drying and sieving the ammonium phosphate granules, thereby yielding ammonium phosphate.

A dust collecting module of a desulfurizing apparatus for removing sulfur oxides is easily installed and facilitates the application of a high voltage to discharge electrodes. The dust collecting module includes an arrangement of discharge electrodes and dust collecting electrodes alternately disposed and spaced apart from each other, the discharge electrodes configured to be charged to a predetermined voltage for generating a corona discharge between the discharge electrodes and the dust collecting electrodes; a first setting beam having a plurality of lower slots into which the discharge electrodes are securely inserted; and a lower frame extending in a stacking direction of the discharge electrodes to support the discharge electrodes, wherein the predetermined voltage is applied to the discharge electrodes through the lower frame and the first setting beam. The dust collecting module may further include an insulating connecting member from which the lower frame is suspended.

A dust collecting module of a desulfurizing apparatus for removing sulfur oxides is easily installed and facilitates the application of a high voltage to discharge electrodes. The dust collecting module includes an arrangement of discharge electrodes and dust collecting electrodes alternately disposed and spaced apart from each other, the discharge electrodes configured to be charged to a predetermined voltage for generating a corona discharge between the discharge electrodes and the dust collecting electrodes; a first setting beam having a plurality of lower slots into which the discharge electrodes are securely inserted; and a lower frame extending in a stacking direction of the discharge electrodes to support the discharge electrodes, wherein the predetermined voltage is applied to the discharge electrodes through the lower frame and the first setting beam. The dust collecting module may further include an insulating connecting member from which the lower frame is suspended.

The invention relates to regenerative, solid sorbent for adsorbing carbon dioxide from a gas mixture, with the sorbent including a modified polyamine and a nano-structured solid support. The modified polyamine is the reaction product of an amine and an aldehyde. The sorbent provides structural integrity, as well as high selectivity and increased capacity for efficiently capturing carbon dioxide from gas mixtures, including the air. The sorbent is regenerative, and can be used through multiple operations of absorption-desorption cycles.

The invention relates to regenerative, solid sorbent for adsorbing carbon dioxide from a gas mixture, with the sorbent including a modified polyamine and a nano-structured solid support. The modified polyamine is the reaction product of an amine and an aldehyde. The sorbent provides structural integrity, as well as high selectivity and increased capacity for efficiently capturing carbon dioxide from gas mixtures, including the air. The sorbent is regenerative, and can be used through multiple operations of absorption-desorption cycles.

Methods for removing sulfur dioxide from a gas stream are disclosed. A method may include passing a gas stream comprising SO.sub.2 through a gas scrubbing apparatus. A scrubbing liquor comprising hydroxide ions and at least one oxidation catalyst may be flowed into the gas scrubbing apparatus, thereby contacting the gas stream with the scrubbing liquor. In response to the contacting, at least 90 wt. % of the sulfur dioxide may be removed from the gas stream. Concomitant to the contacting, at least some of the sulfur dioxide may react with at least some of the hydroxide ions, thereby forming sulfite ions in the scrubbing liquor. Some of the sulfite ions may be oxidized, via the oxidation catalyst, thereby forming sulfate ions in the scrubbing liquor. A used scrubbing liquor may be discharged from the scrubbing apparatus.

Methods for removing sulfur dioxide from a gas stream are disclosed. A method may include passing a gas stream comprising SO.sub.2 through a gas scrubbing apparatus. A scrubbing liquor comprising hydroxide ions and at least one oxidation catalyst may be flowed into the gas scrubbing apparatus, thereby contacting the gas stream with the scrubbing liquor. In response to the contacting, at least 90 wt. % of the sulfur dioxide may be removed from the gas stream. Concomitant to the contacting, at least some of the sulfur dioxide may react with at least some of the hydroxide ions, thereby forming sulfite ions in the scrubbing liquor. Some of the sulfite ions may be oxidized, via the oxidation catalyst, thereby forming sulfate ions in the scrubbing liquor. A used scrubbing liquor may be discharged from the scrubbing apparatus.