Fig. 4. Copper speciation as calculated from Visual MINTEQ as a function of pH and [DOC]/
[Cu] ratio. (A) Activity of free Cu2+ (pCu = −log10 {Cu}, where {Cu} is the activity of
Cu2+). (B) Percentage of copper complexed with dissolved organic matter (DOM). The
black bar depicts the range of pH and [DOC]/[Cu] for the stormwater in our experiments,
and the shaded area depicts the range for the bioretention effluent.