Belebchouche Cherif, Bensebti Salah-Eddine, Ould-Said Chaima, Moussaceb Karim, Czarnecki Slawomir, Sadowski Lukasz
Department of Civil Engineering, Faculty of Sciences of Technology, Frères Mentouri Constantine 1 University, Constantine 25000, Algeria.
Materials and Durability of Constructions Laboratory, Faculty of Sciences of Technology, Frères Mentouri Constantine 1 University, Constantine 25000, Algeria.
Materials (Basel). 2023 Sep 20;16(18):6295. doi: 10.3390/ma16186295.
This article deals with the study of hazardous chromium leaching, stabilized/solidified by cement CEM II after 28 days of curing, in an acidic environment. The mortars subjected to this study were investigated by X-ray diffraction (XRD) characterization to evaluate the influence of chromium waste on their mineralogical structure. In the study range (0.6-1.2%), increasing the mass percentage of CrO in the mortars indicates that chromium accelerates the hydration process and setting of the mortar and increases the mechanical strength of the mortars compared to the control sample. It was observed that the release of chromium during the Toxicity Characteristic Leaching Procedure (TCLP) test and the efficiency of the stabilization/solidification process depended on the initial Cr concentration and the leaching time. The use of XRD allowed the identification of new crystallized phases in the cement matrices, namely, CaCrO·2HO and chromium-ettringite CaCr(SO)(OH)·26HO, which confirms the immobilization of chromium and the efficiency of the stabilization/solidification process. In this research, the release mechanism was found to be primarily a surface phenomenon by modeling the experimental data (dissolution or precipitation).
本文研究了在酸性环境中，养护28天后由CEM II水泥稳定/固化的有害铬的浸出情况。通过X射线衍射（XRD）表征对本研究中的砂浆进行了研究，以评估铬废物对其矿物结构的影响。在研究范围内（0.6%-1.2%），增加砂浆中CrO的质量百分比表明，与对照样品相比，铬加速了砂浆的水化过程和凝结，并提高了砂浆的机械强度。观察到，在毒性特性浸出程序（TCLP）测试期间铬的释放以及稳定/固化过程的效率取决于初始Cr浓度和浸出时间。使用XRD可以识别水泥基体中的新结晶相，即CaCrO·2HO和铬钙矾石CaCr(SO)(OH)·26HO，这证实了铬的固定化以及稳定/固化过程的效率。在本研究中，通过对实验数据（溶解或沉淀）进行建模，发现释放机制主要是一种表面现象。
