Impact of trace metals Zn, Cu, Cd and Ni on the reactivity of OPC and GGBS-based hydraulic binders at early age for sediment stabilization

The solidification/stabilization method was demonstrated to be an effective remediation technology for hazardous waste treatment. Three types of binding agents were tested in the present study view their potential use solidification contaminated sediments and soils – ordinary Portland cement (OPC), granulated ground blast furnace slag (GGBS) activated by OPC a Supersulfated (SSC) binders. An investigation into impact trace metals Zn, Cu, Ni Cd on hydration binders performed adding them pure binders’ systems. Hydration heat evolution assessed through isothermal calorimetry products analysed XRD, NMR XAFS analysis. Copper zinc most perturbing effect early delaying main peak occurrence while nickel cadmium ions do not perturb or accelerate it. For example, GGBS/OPC formulation without any metal addition has its MHP at 13.5 h, with 0.5%Zn appears 37 h later, 0.5%Cu 11.5 but 5 earlier. SSC shown sensitive (TM) addition. electrokinetic conductivity measurements using Zeta Potential apparatus showed decrease obtained values presence Cu Zn increase confirming different behaviours TM considered