En este trabajo se muestra como degradar el DDT (diclorodifeniltricloroetano) y el Gammexano (γ hexaclorociclohexano) utilizando como catalizador TiO₂, el cual fue activado por medio de radiación solar en la banda UV (principalmente λ = 360 nm). Para ello se utilizó un reactor plano rectangular de fibra de vidrio, por el que se hizo circular agua, con dióxido de titanio en suspensión, contaminada con el derivado clorado a degradar. Se tomaron sucesivas muestras a lo largo del tiempo total de la experiencia (540 minutos), a intervalos de 90 minutos, analizándose la concentración del contaminante en cada muestra por cromatografía gaseosa, para obtener la variación de concentración a través del tiempo. | Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES)

A pre-concenvration method for extracting organochlorines from seawater was employed to analyse ΣDDTs and PCBs. The sampling device and the conditions for optimal adsortion performance are described. Recovery tests with spiked solutions were made before applying the method on real samples. Working up of the samples prior to gas chromatographic analysis, precautions and advantages of the procedure are also discussed. The application of the method for seawater, containing very low levels of organochlorines, is shown by data from equatorial surface waters. The average level for ΣDDT and PCBs was 0.21 ng/l and 0.37 ng/l. The overall precision of the method is about ± 15% with a lower limit of detection of 0.1 ng/l-1 for PCBs and 0.05 ng/l-1 for ZDDT.

<abstract language="eng">A pre-concenvration method for extracting organochlorines from seawater was employed to analyse &#931;DDTs and PCBs. The sampling device and the conditions for optimal adsortion performance are described. Recovery tests with spiked solutions were made before applying the method on real samples. Working up of the samples prior to gas chromatographic analysis, precautions and advantages of the procedure are also discussed. The application of the method for seawater, containing very low levels of organochlorines, is shown by data from equatorial surface waters. The average level for &#931;DDT and PCBs was 0.21 ng/l and 0.37 ng/l. The overall precision of the method is about ± 15% with a lower limit of detection of 0.1 ng/l-1 for PCBs and 0.05 ng/l-1 for ZDDT.