Regresar

Degradation of perchlorate dissolved in water by a combined application of ion exchange resin and zerovalent iron nanoparticles

Abstract:

Perchlorate (ClO−4) is an anion that has a chloride atom with an oxidation state of positive seven. This compound holds a tetrahedral geometry, formed with four oxygen atoms, and its negative charge is stabilized by mesomeric effects (Urbansky, 2002). Due to this symmetrical configuration, perchlorate anion shows a high chemical stability. Also, ClO−4 exhibits high water solubility and low vapor pressure, properties that converts to perchlorate in an important contaminant of water systems (ITRC, 2005; Urbansky, 2002). Perchlorate is produced either by natural or anthropogenic sources. A place where ClO−4 naturally occurred is at saltpeter deposits of Chile (Dadoly, 2005). In contrast, the anthropogenic perchlorate contamination comes from the use of perchlorate salts and perchloric acid; mainly in the manufacturing of fertilizers, dyes and paints, explosives, fireworks, etc. (Urbansky, 2002). Salts of perchlorate are particularly used by the ammunition and military industry or industry related to aerospace programs. For example, ammonium perchlorate is utilized as a solid oxidant in fuel of missiles, ammunitions and in propulsion systems of rockets (Rogers, 1998; Urbansky, 2002). The intensive use of perchlorate compounds builds up contamination mostly on surface and in ground bodies of water; developing large plumes which can reach up to 14.5 km of length. For this reason, this toxic compound is considered culprit of awful environmental impacts (EPA, 2007).