Corrosion and Sustainable Infrastructure Laboratory, Western Transportation Institute and Civil Engineering Department, PO Box 174250, College of Engineering, Montana State University, Bozeman, MT 59717-4250, USA; Laboratory of Road Ecology and Pollution Emergency Response, Research Center for Environmental Protection and Transportation Safety, China Academy of Transportation Sciences, Beijing 100029, China.
Laboratory of Road Ecology and Pollution Emergency Response, Research Center for Environmental Protection and Transportation Safety, China Academy of Transportation Sciences, Beijing 100029, China.
Water Res. 2014 Oct 1;62:88-96. doi: 10.1016/j.watres.2014.05.021. Epub 2014 Jun 2.
Cement-based and alternative cementitious materials were tested in the laboratory for their capability of removing phosphate from wastewater. The results demonstrated that both Langmuir and Freundlich adsorption isotherms were suitable for describing the adsorption characteristics of these materials. Among the four types of filter media tested, the cement-based mortar A has the highest value of maximum adsorption (30.96 mg g(-1)). The P-bonding energy (KL) and adsorption capacity (K) exhibited a positive correlation with the total content of Al2O3 and Fe2O3 in each mortar. The maximum amount of P adsorbed (Qm) and adsorption intensity (1/n) exhibited a positive correlation with the CaO content in each mortar. For three of them, the P-removal rates were in excess of 94 percent for phosphorus concentrations ranging from 20 to 1000 mg L(-1). The underlying mechanisms were examined using field emission scanning microscopy (FESEM), coupled with energy-dispersive X-ray spectroscopy (EDX) and X-ray powder diffraction (XRD). The results reveal that the removal of phosphate predominantly followed a precipitation mechanism in addition to weak physical interactions between the surface of adsorbent filter media and the metallic salts of phosphate. The use of cement-based or alternative cementitious materials in the form of ground powder shows great promise for developing a cost-effective and environmentally sustainable technology for P-sequestration and for wastewater treatment.
水泥基和替代胶凝材料在实验室中进行了磷酸盐去除能力的测试。结果表明，Langmuir 和 Freundlich 吸附等温线都适合描述这些材料的吸附特性。在所测试的四种过滤介质中，水泥基砂浆 A 具有最高的最大吸附值（30.96mg/g）。P 键合能（KL）和吸附容量（K）与每种砂浆中的总 Al2O3 和 Fe2O3 含量呈正相关。最大吸附量（Qm）和吸附强度（1/n）与每种砂浆中的 CaO 含量呈正相关。对于其中三种，当磷浓度范围在 20 到 1000mg/L 时，磷的去除率超过 94%。使用场发射扫描显微镜（FESEM），结合能量色散 X 射线光谱（EDX）和 X 射线粉末衍射（XRD）对其去除机理进行了研究。结果表明，磷酸盐的去除主要遵循沉淀机理，同时在吸附剂过滤介质表面和磷酸盐的金属盐之间存在弱的物理相互作用。以磨碎粉末形式使用水泥基或替代胶凝材料，为开发经济高效和环境可持续的 P 封存和废水处理技术提供了广阔的前景。
