An apparatus and process are provided for electricity production and high-efficiency trapping of carbon dioxide, using carbon dioxide within combustion exhaust gas and converging technologies associated with a carbon dioxide absorption tower and a generating device using ions which uses a difference in concentration of salinity between seawater and freshwater. It is expected that enhanced electrical energy production efficiency, an effect of reducing costs for the operation of a carbon dioxide trapping process, and electricity production from carbon dioxide, which is a greenhouse gas, can be simultaneously achieved by increasing the difference in concentration using an absorbent for absorbing carbon dioxide.

Materials and methods for mitigating the effects of halide species contained in process streams are provided. A halide-containing process stream can be contacted with mitigation materials comprising active metal oxides and a non-acidic high surface area carrier combined with a solid, porous substrate. The halide species in the process stream can be reacted with the mitigation material to produce neutralized halide salts and a process stream that is essentially halide-free. The neutralized salts can be attracted and retained on the solid, porous substrate.

The use of a composition including at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, the acido-basic neutralising agent having at least 2 pKa's and being characterised by: pKa 1≤pKa 2, pKa 1>2, pKa 2<12, 4<½ (pKa 1+pKa 2)<10 pKa 1, representing the smallest of the basic pKa's and pKa 2 representing the largest of the acidic pKa's. Also, a method for decontaminating an atmosphere contaminated by a corrosive gas comprising the spraying of the neutralising agent, and to a decontamination device.

The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.

Methods and compositions are described that remove chlorine from a chlorine-containing gas stream. The method includes adding a carbonate salt and optionally a scale inhibitor to a scrubbing liquid in a wet scrubbing system, and contacting the chlorine-containing gas with the scrubbing liquid. The amount of carbonate salt that is added can vary depending on the pH of the scrubbing liquid.

Materials and methods for mitigating the effects of halide species contained in process streams are provided. A halide-containing process stream can be contacted with mitigation materials comprising active metal oxides and a non-acidic high surface area carrier combined with a solid, porous substrate. The halide species in the process stream can be reacted with the mitigation material to produce neutralized halide salts and a process stream that is essentially halide-free. The neutralized salts can be attracted and retained on the solid, porous substrate.

Methods and compositions are described that remove chlorine from a chlorine-containing gas stream. The method includes adding a carbonate salt and optionally a scale inhibitor to a scrubbing liquid in a wet scrubbing system, and contacting the chlorine-containing gas with the scrubbing liquid. The amount of carbonate salt that is added can vary depending on the pH of the scrubbing liquid.

A mercury sorbent and method for enhancing mercury removal performance of activated carbon from flue gas by the addition of non-halogen ammonium-containing compounds are provided herein.

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.

Gels that can react with air pollutants in air and methods for making said gels, are provided. The gels are useful for removing air borne pollutants from indoor environments.