Enhancing the Ability of Pervious Concrete to Remove Heavy Metals from Stormwater

Abstract

Catastrophic release of heavy metals from the King River mine in Colorado and the Minas Gerais dam in Brazil have brought to the forefront the importance of contaminant stabilization and remediation in surface waters. Permeable reactive materials are currently utilized for the remediation of heavy metals and other pollutants by employing reactive media to remove contaminants. This research investigated the use of fly ashes with loss on ignition or sulfur trioxide exceeding ASTM C618 limits to enhance pollutant removal in pervious concrete. The high carbon and sulfur contents of the noncompliant fly ashes provide additional capacity to remove lead, cadmium, and zinc. High-sulfur and high-carbon fly ashes were less effective in metal removal at higher metal concentrations but improved removal at lower concentrations. These results suggest pervious concrete can be designed as an effective remedial technique for use in many infrastructure applications, including beneath permeable pavement, permeable asphalt, revetment, permeable shoulders, gabions for slope stability, mine tailing dams, and emergency surface water cleanup.