School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
J Colloid Interface Sci. 2013 Jul 15;402:246-52. doi: 10.1016/j.jcis.2013.03.057. Epub 2013 Apr 11.
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) (Fe(3+)) or iron (ii) (Fe(2+)) 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.
磷吸附去除是人工地下流湿地中一种重要且高效的处理工艺。许多材料已被提议用于从废水中去除过量的磷。因此，选择具有高磷吸附能力的基质对于获得显著的磷去除非常重要。在这项研究中，评估了海绵铁和沸石的磷去除能力，并将其与物理化学特性相关联。通过批处理实验研究了影响海绵铁和沸石从水溶液中吸附去除磷的潜在机制。准二级动力学非常有用，因为吸附速率数据拟合得很好。Freundlich 和 Langmuir 模型很好地描述了吸附等温线数据。静态实验和动态实验（柱实验）的结果表明，磷在海绵铁上的吸附更倾向于化学结合，但沸石更倾向于静电吸引或离子交换。对于海绵铁，一些铁（III）（Fe(3+)）或铁（II）（Fe(2+)）和磷酸根离子（P）形成 Fe-P，固定了固相化合物。对于沸石，氧化铝和氧化硅在水溶液中形成配合物。观察到由于静电吸引或离子交换，带正电荷或负电荷的表面位点有利于磷酸根的吸附。
