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.

A nitrogen oxide absorption slurry and its preparation and use method for the removal of nitric oxide in gas streams, belonging to the technical field of air pollution control and related environmental protection, is characterized in that the absorption slurry contains one or more compounds of anhydrous ferric chloride, ferric chloride monohydrate, ferric chloride dihydrate and the complex of ferric chloride and chloride ions. The absorption slurry reacts with the nitric oxide in gas stream at a certain temperature, so that the nitric oxide in the gas stream is absorbed by the slurry, thereby achieving the purpose of gas purification. And the absorbent can be recycled after regeneration.

The invention relates to water-soluble and/or dispersible ferric hydroxide in a strong base that is suitable for hydrogen sulfide removal in contaminated liquid and gas streams. The water-soluble and/or dispersible ferric hydroxide in a strong base may be introduced into a liquid stream to remove hydrogen sulfide. The water-soluble and/or dispersible ferric hydroxide may be further incorporated into a solid substrate for gas phase hydrogen sulfide removal.

The present invention discloses a dehumidification bag capable of being placed in multiple forms, having a bag body and a moisture absorbing medium placed in the bag body, wherein the surface of the bag body is provided with a gas permeable zone, the rest is a sealing zone except for the gas permeable zone, and the moisture absorbing medium absorbs moisture in air through the gas permeable zone; and the bottom of the bag body is provided with an expanding portion that allows the bag body to be placed upright. The present invention has the following beneficial technical effects: the present invention is simple in structure and convenient to use; the present invention not only reduces the use of space, but also maximizes the applicable range; secondly, since the present invention is suitable for different placement postures, it can be placed freely on the premise of ensuring that the gas permeable zone is not blocked; thirdly, the present invention minimizes the impact on the environment and has a beneficial environment-friendly effect; and finally, the sealing zone is printable with patterns or is provided with shapes such that the friendliness to end consumers is greatly improved and the product is no longer monotonous, and the bag body can be of any shape to meet the needs of different consumers.

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

The present invention discloses a method for preparing iron ore concentrates by recycling copper smelting slag tailings, and belongs to the technical field of metallurgy and tailings recycling. In the present invention, copper slag tailings obtained after copper pyrometallurgy and flotation and water are used as raw materials, and low-concentration sulfur dioxide flue gas is used as a leaching agent for leaching of metals such as iron, zinc, copper, arsenic, and silicon in the slag tailings; the leachate is purified step by step through processes such as replacement by metal iron powder and sulfide precipitation control, to separate zinc, copper, arsenic, etc.; a purified solution is mainly composed of FeSO.sub.4 or can be used for producing a ferric salt flocculant; obtained tailings are used to obtain iron ore concentrates through magnetic separation, and the obtained iron ore concentrates can be used for further producing ultra-pure iron ore concentrates.

A nitrogen oxide absorption slurry and its preparation and use method for the removal of nitric oxide in gas streams, belonging to the technical field of air pollution control and related environmental protection, is characterized in that the absorption slurry contains one or more compounds of anhydrous ferric chloride, ferric chloride monohydrate, ferric chloride dihydrate and the complex of ferric chloride and chloride ions. The absorption slurry reacts with the nitric oxide in gas stream at a certain temperature, so that the nitric oxide in the gas stream is absorbed by the slurry, thereby achieving the purpose of gas purification. And the absorbent can be recycled after regeneration.

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

The present development is a method for capturing and purifying CO.sub.2 from a flue gas stream using a metal aluminate nanowire absorbent and then regenerating the absorbent. After the CO.sub.2 is adsorbed into the absorbent, the adsorbent is regenerated by subjecting the CO.sub.2 saturated adsorbent to a dielectric barrier discharge plasma or to a microwave plasma or to a radio frequency (RF) plasma while ensuring that the external temperature does not exceed 200° C.

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.