Abstract
Chemical reactivity, bioavailability, and mobility of trace metals in aquatic systems are strongly influenced by complexation with dissolved organic matter (DOM). A monitoring survey has been conducted in the Sagami River basin to elucidate the relation between trace metal solubility and DOM molecular properties in natural waters and wastewater effluents. For all the samples collected and analyzed, the concentrations of dissolved copper (Cu) and iron (Fe), both of which are normalized to dissolved organic carbon concentration, were found to be strongly positively correlated with SUVA254, an optical index representing DOM aromaticity. Calculation using a chemical equilibrium speciation model predicted that the majority of these dissolved metals are present as the complex with DOM in these samples. It can be concluded that the amount of trace metals (Cu, Fe) complexed with an unit mass of DOM is identically controlled by DOM aromaticity in a range of natural waters and wastewater effluents.
