Complexation side reactions involving trace metals in natural water systems1

Descriptions of trace metal speciation in natural freshwater systems arc facilitated by the use of side reaction coefficients and conditional stability constants which permit simultaneous consideration of competing complexation reactions. Some specific descriptons are presented which illustrate the extreme dependence of speciation on pH and anionic concentrations. At low pH, hydroxide complexation is likely to be overshadowed by complexation by other anions. At high pH, polynuclear complexation becomes important.