Solidification/stabilization of lead-contaminated soil using cement and waste phosphorus slag

Solidification/stabilization (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of waste phosphorus slag (WPS) for S/S treatment of contaminated soils. Partial replacement of ordinary Portland cement (OPC) with WPS in the binder system is used to S/S of lead-contaminated soil. Batch tests were conducted to study the physical properties of solidified forms with different concentrations of lead and WPS, namely unconfined compressive strength (UCS), setting times of early mixtures and changes in crystalline phases as well as chemical properties such as the leachability of lead and pH of the leachate. Results indicated that partial replacement of OPC with WPS could reduce the Pb leaching concentration of solidified samples effectively. XRD results indicated that the formation of fluoropyromorphite was strongly associated with the immobilization of lead. (c) 2014 American Institute of Chemical Engineers Environ Prog, 34: 957-963, 2015