engleski

An electrochemical approach to organic aggregation

We study aggregation processes of organic matter in stratified Mediterranean estuaries. A fast aggregation and importance of hydrophobic interactions have been inferred. The electrochemical probe, renewable mercury sphere electrode, allowed simultaneous detection of submicron particles collective response and individual attachment signals of larger reactive partcles (um size). Estuarine fluid surface active particles seem to be closely related to flexible transparent exopolymeric particles indentified more recently. The electrode is used as a model interface in order to decouple physico-chemical interactions in the interfacial process involving extracellular polymers, marine bacteria and phytoplankton cells. Laboratory experiments were performed in diluted seawater and conditions of enhanced transport by convective streaming. Hydrophobic interactions were identified to prevail over electrostatic repulsion in the attachment of aggregated bacteria, nanoflagellates and flexible nonliving aggregates.

organic aggregation; Mediterranean estuaries; hydrophobic interaction

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