Bioremediation of toxaphene contaminated soils: Optimization of processes under anaerobic and aerobic conditions.

Toxaphene is an insecticide, consisting of a complex mixture of approximately 1000 chlorinated bicyclic terpenes that was included in the first list of persistent organic pollutants (POPs) banned by the Stockholm Convention (Vetter and Oehme 2000; Korytár et al. 2003; Kapp and Vetter 2009). Until the mid-1980s, toxaphene was one of the most used pesticides in Colombia, as well as in the rest of the world, mainly in cotton crops. Several sites in Colombia are known to be contaminated with this insecticide (MAVDT, 2007, 2010). Usually these sites are related to cotton cultivation. This crop suffered an economic crisis leading many growers to bankruptcy, a large amount of toxaphene that had already been imported into Colombia became obsolete. Some of them were buried underground without any security measures, while others were improperly stored in Cenalgodon warehouses located in the municipality of El Copey, Cesar) leading to soil and water contamination with concentrations up to 10,000 mg*Kg-1 (MAVDT, 2007, 2010, Arbeli et al., 2015).
Among the generalizations of biodegradation of organochlorine compounds, it has been determined that the compounds with the highest number of chlorines are more susceptible to anaerobic degradation (reductive dehalogenation) and the lower number of chlorines are more susceptible to aerobic degradation (e.g. oxidative dehalogenation) (Fetzner, 1998; Haggblom and Bossert, 2003; van Pée and Unversucht, 2003). Therefore, for many of the POPs it seems more attractive to employ a combined anaerobic-aerobic process (Haggblom and Bossert, 2003; van Pée and Unversucht, 2003; Bunge and Lechner, 2009; Payne et al., 2013; Pathiraja et al., 2019).

Se busca identificar la mejor estrategia para eliminar metabolitos toxicos del toxafeno