Arias C A, Brix H
Department of Biological Sciences, University of Aarhus, Ole Worms Alle, Building 135, 8000 Aarhus C., Denmark.
Water Sci Technol. 2005;51(9):267-73.
Removal of phosphorous in constructed wetlands is limited by the capacity of the media to adsorb, bind or precipitate the incoming P. To enhance P removal and the life span of constructed wetlands the approach might be to use natural sands rich in calcium or iron, to use an alternative 'artificial' medium with high P-binding capacity, or to establish external P-binding filters after the wetland. Our studies focused on the evaluation of calcium-rich materials potentially useful as P-binding media. The materials tested included calcite products, natural sands and seashells. Tests included assessment of physical and chemical properties of the materials, extractions in P-spiked water at different P concentrations to determine P-binding equilibrium isotherms, and column experiments. In addition, full-scale tests were performed with calcite in an external filter. The result showed that equilibrium isotherm is an indicator of the potential P-sorption capacity of the media, although the value is of limited application for the determination of the binding capacity in full-scale systems. The columns showed that the materials do bind phosphorus. However, the binding capacities are still insufficient for the establishment of external P-removal filter; the volumes of the filters would be too large to be of practical use.
人工湿地中磷的去除受介质吸附、结合或沉淀进入的磷的能力限制。为了提高磷的去除率和人工湿地的使用寿命，方法可能是使用富含钙或铁的天然砂，使用具有高磷结合能力的替代“人工”介质，或在湿地后建立外部磷结合过滤器。我们的研究集中在评估可能用作磷结合介质的富含钙的材料。测试的材料包括方解石产品、天然砂和贝壳。测试包括评估材料的物理和化学性质，在不同磷浓度的加磷水中进行萃取以确定磷结合平衡等温线，以及柱实验。此外，在外部过滤器中对方解石进行了全尺寸测试。结果表明，平衡等温线是介质潜在磷吸附能力的指标，尽管该值在确定全尺寸系统中的结合能力方面应用有限。柱实验表明这些材料确实能结合磷。然而，结合能力仍不足以建立外部除磷过滤器；过滤器的体积会太大而不实用。
