Ammonia (NH₃) removal from air.

Introduction Ammonia (NH₃) is a colourless, low molecular weight gas with the chemical formula NH₃ (See figure 1). It has a pungent smell, often associated with strong household cleaners. Ammonia (NH₃) is lighter than air but can be easily condensed to a liquid due to strong hydrogen bonding between the ammonia molecules (hydrogen bonding is…

Nickel (Ni²⁺) removal from water using chelating resins.

Where does nickel come from? Pure nickel (Ni) is a silvery-white metal that is rarely found as a pure metal in the earth’s crust because it will oxidise when it comes into contact with oxygen. Pure nickel can be found in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside the earth’s atmosphere or in ultramafic rocks.   Nickel is…

Mercury (Hg⁰ and Hg²⁺) removal from water.

Introduction Mercury species exists in various forms: elemental (or metallic); inorganic (e.g. mercuric chloride); and organic mercury (e.g., methyl- and ethylmercury), which all have different toxic effects. Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), inhalation of mercury vapour, or by ingesting any form of mercury.…

Arsine (AsH₃) removal from air.

Introduction Arsine (AsH₃) is an extremely toxic gas that is generated upon exposure of arsenic-containing ores to acids. It is also a by-product of refining of non-ferrous metals. Arsine is used extensively in the manufacture of microchips, solid-state lasers and for the synthesis of organoarsenic compounds. Arsine (AsH₃) is a colourless, flammable, non-irritating toxic gas…

Phosphine (PH₃) removal from air.

Introduction Phosphine is the compound with the chemical formula PH₃. Phosphine (PH₃) is used as an intermediate in organophosphorus chemistry and as a dopant in the semiconductor industry. Phosphine (PH₃) is alsowidely used as a fumigant (for example, in the tobacco industry) that does not leave residues on the stored product, and for pest control.…