Pérez M M, Bossens J, Rosa E, Tack F M G
Study Center of Applied Chemistry, Chemical Pharmacy Faculty, Central University of Las Villas, Cuba E-mail:
Department of Applied Analytical and Physical Chemistry, Bioscience Engineering Faculty, Ghent University, Belgium.
Water Sci Technol. 2014;70(9):1561-8. doi: 10.2166/wst.2014.410.
In this study the main physical-chemical characteristics of red ferralitic soil to use as substrate in subsurface wetlands was determined. The P-removal was evaluated in a short-term isotherm batch experiment and in a column percolation experiment. The acid characteristic and high content of iron minerals in the red ferralitic soil facilitated the phosphorus removal. Also the sorption isotherms at two different temperatures were obtained. The results showed that the sorption capacity increases with an increase in solution temperature from 25 to 35 °C. The experimental data were fitted to Langmuir and Freundlich models, having a better fit to the Freundlich isotherms. The maximum P-sorption capacities estimated using the Langmuir isotherm were 0.96 and 1.13 g/kg at 25 and 35 °C respectively. Moreover a column experiment was carried out at two different flows. Sequential extractions of the phosphorus-saturated soil indicated that phosphorus is mainly bound with iron or aluminum minerals. The results have demonstrated a good potential for red ferralitic soil for phosphorus removal from urban wastewater.
本研究测定了赤红壤用作潜流湿地基质的主要物理化学特性。在短期等温间歇实验和柱渗流实验中评估了磷的去除情况。赤红壤的酸性特征和高含量的铁矿物有利于磷的去除。同时还获得了两种不同温度下的吸附等温线。结果表明，吸附容量随着溶液温度从25℃升高到35℃而增加。实验数据拟合了朗缪尔和弗伦德利希模型，弗伦德利希等温线拟合效果更好。使用朗缪尔等温线估计的25℃和35℃下的最大磷吸附容量分别为0.96和1.13 g/kg。此外，在两种不同流速下进行了柱实验。对磷饱和土壤的连续提取表明，磷主要与铁或铝矿物结合。结果表明，赤红壤在去除城市废水中的磷方面具有良好的潜力。
