Various types of dissolved organic acids along with the methods used when separating into fractions. Current methods, although more suffisticated, are all based on the above principles. Environmental Concentrations DOC concentration vary according to the make up of the surrounding environment. This is due to the trapping of water and material by the aquatic and land based plant life. A listing of the average DOC concentrations found in surface and ground waters of North America.
Values are average concentrations.
DOC's are small mobile particles that can pick up bound or undissolved metals in the environment. Binding increases the amount of metal dissolved in the solution, even though it does not increase toxicity or bioavailability. Two environmental factors that affect DOC's ability to bind and dissolve metals is the pH and temperature of the water. Metal Binding There are two types of interactions between DOC and metals. Ionic interactions occur predominantly with metals that are electropositive having low ionization potentials.