Abstract

AGUDELO, Diana María; FLOREZ, María Teresa; LOPEZ, Carlos  and  PALACIO, Jaime. INFLUENCE OF PHYSICAL-CHEMICAL CONDITIONS OF SEDIMENT AND WATER-SEDIMENT INTERFACE ON EXPERIMENTAL TRANSFER OF O,O-DIETHYL O-(3,5,6-TRICHLORO-2-PYRIDINYL PHOSPHOROTHIOATE AND 3,5,6-TRICHLORO-2-PYRIDINOL (TCP) AT ''RIOGRANDE II'' RESERVOIR. Rev. ing. univ. Medellín [online]. 2013, vol.12, n.23, pp.13-22. ISSN 1692-3324.

By this experimental research influence of some physical-chemical variables of sediments coming from ''Riogrande II'' Reservoir and water-sediment interface on the transfer of Chlorpyrifos and TCP has been evaluated. The analysis of Chlorpyrifos and TCP in sediments and water was performed by extraction in solid phase. Samples were detected by gas chromatography coupled to mass spectrometry (Trace GC Ultra MS 2030-Thermo Scientific). There were evidences of a strong adsorption of both compounds in sediments given the elevated content of clays and organic carbon, which limited their mobility towards the interface. The water-sediment interface was characterized by a condition of hypoxia during the entire experimental phase, while electrical conductivity increased through time. It was determined that a neutral pH or a slightly alkaline pH caused an increase of chlorphyrifos concentration in the water-sediment interface, which suggests a transfer increase from the sediment to the interface, while a slightly acid pH caused the transformation of parental compound in the sediment.

Keywords : Sediment; water-sediment interface; transfer; chlorpyrifos; TCP.

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