Removal of Heavy Metals from Stormwater Using Porous Concrete Pavement

Abstract

This study aimed to investigate the heavy metals, i.e. Cu, Pb, Ni, and Zn removal efficiency from stormwater runoff of a porous concrete pavement (PCP). A model of PCP was designed with the porosity and co-efficient of permeability of the pavement were 27.2% and 1.83 cm/sec, respectively. Artificial stormwater containing heavy metals are passed through the pavement at a constant rainfall rate to mimic the stormwater rainfall-runoff condition. The artificial stormwater infiltrated through the pavement were then collected at two different pavement layers at different time instances. From the experimental investigations, it is observed that Cu, Pb, Ni and Zn concentrations are significantly reduced in the treated stormwater. At the first collection point which is located below the sub-base layer and coarse sand layer of the pavement, the concentrations of Cu, Pb and Zn reduced 56%, 67% and 93% respectively compared to their initial concentration, Ni concentration reduced only 20%. At the second collection point which is located below the coarse and fine sand layers beneath the pavement, the concentrations of Cu, Pb, Zn, and Ni are reduced 92%, 89%, 100%, 100%, respectively.