TY - JOUR AU - Chen, P. AU - Chen, X. AU - Wang, Y. AU - Wang, P. PY - 2020/06/30 Y2 - 2024/03/28 TI - Preliminary study on the upcycle of non-structural construction and demolition waste for waste cleaning JF - Materiales de Construcción JA - Mater. constr. VL - 70 IS - 338 SE - Research Articles DO - 10.3989/mc.2020.13819 UR - https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/2285 SP - e220 AB - This study proposes a method to convert non-structural calcium-rich construction and demoli­tion waste fines into adsorbents of heavy metal ions by mixing waste fines with diammonium hydrogen phos­phate solution to produce hydroxyapatite, which has high surface areas and excellent ion-exchange capacity with heavy metal ions. As a result, environmental polluting waste is converted into environmentally cleaning material. Waste putty powders was chosen as the representative waste to investigate the detailed formation process of hydroxyapatite and the key reaction parameters of the reaction. Results showed that hydroxyapatite can be pro­duced on waste putty particles. Higher ageing temperatures or longer ageing duration are beneficial to the yield and crystallinity of the produced hydroxyapatite. Adsorption testing confirmed that Ni<sup>2+</sup> can replace Ca<sup>2+</sup> in the hydroxyapatite lattice, leading to the formation of a new crystal, arupite (Ni<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>•8H<sub>2</sub>O), and contributing to a modest adsorption capacity for Ni<sup>2+</sup> (15 mg/g) for the hydroxyapatite-containing waste putty. ER -