Details

Autor(en) / Beteiligte

• Wang, Xinjun
• Chen, Jiding
• Kong, Yaping
• Shi, Xianming

Titel

Sequestration of phosphorus from wastewater by cement-based or alternative cementitious materials

Ist Teil von

• Water research (Oxford), 2014-10, Vol.62, p.88-96

Ort / Verlag

Kidlington: Elsevier Ltd

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• 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. [Display omitted] •We tested the P-sequestration capability of hydrated cementitious materials.•Both Langmuir and Freundlich adsorption isotherms were suitable.•Four mortars showed maximum P-adsorption of 30.96, 23.75, 20.20, and 12.7 mg g−1 respectively.•P-removal rates of three mortars exceeded 94% for P solutions at 20–1000 mg/L.•The underlying mechanisms were examined using FESEM/EDX/XRD.