Adsorptive removal of phosphorus from aqueous solution using sponge iron and zeolite

• Published in: Journal of colloid and interface science Vol. 402; pp. 246 - 252
• Main Authors: Jiang, Cheng, Jia, Liyue, He, Yiliang, Zhang, Bo, Kirumba, George, Xie, Jie
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 15.07.2013; Elsevier
• Subjects: Adsorption; Adsorptive removal; Adsorptivity; Aluminum oxide; Aqueous solutions; Chemistry; electrostatic interactions; Exact sciences and technology; General and physical chemistry; Ion-exchange; ions; iron; phosphates; Phosphorus; silicon; sorption isotherms; Sponge iron; subsurface flow; Surface chemistry; Surface physical chemistry; wastewater; wetlands; Zeolite; Zeolites; Zeolites: preparations and properties; Adsorptive removal; Phosphorus; Sponge iron; Zeolite; Transition metal; Iron; Aqueous solution; Molecular sieve
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2013.03.057

[Display omitted] •Mechanisms of adsorptive P onto sponge iron and zeolite were investigated.•The analysis of different P adsorption mechanisms for the different P forms was conducted.•By desorption experiment, analyze the physical/chemical adsorption properties.•Adsorption of phosphorus onto sponge iron was inclined to chemical combination.•Adsorption of zeolite was inclined to electrostatic attraction or ion-exchange. Phosphorus adsorptive removal is an important and efficient treatment process in constructed subsurface flow wetlands. Many materials have been proposed for removal of excess phosphorus from wastewater. Selecting a substrate with a high phosphorus adsorption capacity is therefore important in obtaining significant phosphorus removal. In this study, the phosphorus removal capacities of sponge iron and zeolite were evaluated and related to their physico-chemical characteristics. The potential mechanisms affecting the adsorptive removal of phosphorus from aqueous solutions onto sponge iron and zeolite were investigated in batch experiments. The pseudo-second-order kinetics were useful since the adsorption rate data fitted well. The Freundlich and Langmuir models well described the adsorption isotherm data. The results of static experiments and dynamic experiments (column experiments) indicated that the adsorption of phosphorus onto sponge iron was more apt to chemical combination, but zeolite was more apt to electrostatic attraction or ion-exchange. For sponge iron, some iron (iii) (Fe3+) or iron (ii) (Fe2+) and phosphate ions (P) form Fe–P, the solid phases compound was fixed. For zeolite, aluminum oxide and silicon oxide formed complexes in aqueous solution. It was observed that positive or negative charge surface sites favored the adsorption of phosphate due to the electrostatic attraction or ion-exchange.