Abstract
Ultrafiltration through 100, 25, and 5nm filters besides conventional filtration of 450nm was performed to examine the effects of nanominerals on chemical analyses of river waters. In our previous study at the Lampa river, Santiago, Chile, sudden decrease of pH and increase of Eh and SO42- followed by variations of trace metal concentrations were observed at one part of the river (Rocco, 2008). The increase of ions implies dissolution of sulfates and the decrease of trace metals suggests that they were carried by secondary formed Fe nanominerals. Ultrafiltration was intended to remove the effects of nanominerals on chemical analyses. Filtered waters of 5nm filters showed different concentrations from those of larger pored filters. These tendencies of concentrations varied among trace metals and Fe that form nanominerals.
