Behavior of Heavy Metals, Nutrients, and Major Components during Roof Runoff Infiltration

Abstract

The behavior of heavy metals (Cd, Cu, Zn, Cr, Pb), nutrients (organic C, P, and N parameters), and major ions was investigated during percolation of roof runoff water through an artificial infiltration site. The concentrations of the various components were determined in rainwater, roof runoff, and infiltrating water at various depths in the soil. The concentrations of most parameters in roof runoff were highest during the “first flush” at the beginning of rain events. Despite rapid infiltration caused by strong preferential flow, differences were still observed in infiltration behavior between individual compounds. Cl-, NO3-, SO42-, ortho-phosphate, and the major part of DOC behaved essentially conservatively during infiltration, whereas NH4+ concentration decreased probably as a consequence of nitrification. The concentrations of Ca, Mg, Na, K, and alkalinity were regulated by dissolution of soil material. The change in concentrations of Cu, Cd, and Cr during infiltration was mostly due to the concentra...