Evaluation of the Impact of Ni, Cr and Pb Contained in Effluents of an Industrial unit by the Process of Stabilization/solidification using Hydraulic Binders

Stabilization/ solidification (S/S) of hazardous waste by hydraulic binders is one of the most promising ways to reduce the polluting nature of ultimate waste. This study conducted at the laboratory scale, to study of the influence of various parameters namely: the ratio L/S, the contact time solid/liquid, surface and medium of exposure...etc., on the environmental impact of ultimate waste synthesized and real-discharges of an industrial unit, stabilized/ solidified by hydraulic binders. The ANC test, pore water and leaching test on monoliths were carried on samples of the same material to study the influence of pH, L/S ratio and other parameters on the chemical speciation of the species (Pb2+, Cr+3 and Ni+2) in granular materials. Monitoring of the changes in concentrations (TLM test), flows leached and cumulative concentrations of chemical species are used as a criterion for comparison. The use of X-ray diffraction (XRD) is effective for the determination of crystalline phases. The results of XRD may indicate the mechanisms and reactions of immobilization occurring in the process of S/S. The experimental results obtained for the scenario shown indicate that the release of chromium is purely diffusive in against the leaching of lead and nickel is combined by diffusion and chemical reaction.