Heavy Metal Interaction with Aquatic Humus

Abstract

A main part of all dissolved organic carbon (DOC) in surface waters is due to humic substances (HUS). Their complexation of heavy metals may cause biological effects and disturb water treatment steps. Because of this importance complexation capacities of HUS and any related parameters are of interest. A method for determination uses polarographic (DPP/DME) titrations in respect of copper. HUS isolated from different rivers and lakes show in general some μmol complexation capacities per mg DOC depending on the kind of original water, and on the seasonal time of sampling. Brown water and winter samples have the smallest capacities.

Many of the water quality data of the original surface waters are in good agreement with these results. Especially concentrations of dissolved heavy metals like iron, mercury and lead can be explained by taking into account the complexation ability of aquatic HUS.

Key Words:

• Surface water
• heavy metals
• humic substances
• complexation
• polarography