Immobilization of industrial waste in cement-bentonite clay matrix

Abstract

Results of a series of experimental tests performed to determine the influence of matrix characteristics on the leaching mechanism of copper aluminum oxychloride immobilized into cement matrices are presented. The objective of this work was to investigate the leaching mechanism of copper as a constituent of copper aluminum oxychloride ('CAOX'). Transport phenomena involved in the leaching of a waste material from a composite matrix into surrounding water were investigated using three methods based on theoretical equations: (i) diffusion equation derived for a plane source model, (ii) rate equation for diffusion coupled with a first-order reaction and (iii) the leaching data were also analysed by an empirical method employing a polynomial equation. These three methods are compared with respect to their applicability to the leaching data.

Stabilization of Cu (II) wastes by C3S hydrated matrix

“…This was done using diffusion equation based on plane source model [8,16]. Table 3 shows the results of leached Cu (II) ions (a n ) and a n /A 0 of C 3 S samples doped with 3 wt.% Cu (II) ions at various leaching periods.…”

“…For C 3 S-doped with 1 and 3 wt.% Cu (II) ions the rate of diffusion of leached Cu (II) ions from C 3 S hydrated matrix was calculated using diffusion equation based on plane source model [8,16]. In this model the fraction, f, leached at time, t (d) is calculated using the following equation:…”

“…Xu et al [7] studied the solidification/ stabilization of copper containing sewage sludge in ceramics and its thermal stability. Plecas and Dimovic [8] studied the immobilization of copper aluminum oxy chloride in cement bentonite clay matrix. Cu (II) immobilization in OPC and its blended derivatives were studied by many authors [9][10][11].…”

A study on leaching behaviour of cement blocks used as matrix for fixation of Cs activity along with ferric

“…Its high pH tends to keep the materials in the most insoluble form thus minimizing subsequent leaching. Portland cement is less useful with organics since some of them interfere with the overall setting and curing process (Plecas and Pavlovic 2004).…”

Optimising the mixing proportion of solidified landfill waste for sustainable reuse in paving block construction

“…In previous study, the polynomial equation-based leachate model was found to be applied for the representation of leaching mechanisms of heavy metals from radioactive waste-concrete composites (Plecas, 2003;Dimovic, 2009, 2011). In addition, Plecas and Dimovic (2004) employed nonlinear leachate model successfully for the demonstration of copper aluminium oxychloride leaching mechanism from industrial waste-cement-bentonite clay matrix. The suitability of polynomial equation-based leachate model for explaining the leachate behaviour of heavy metals from solidified landfill waste is yet to be studied.…”