Jang Am, Seo Youngwoo, Bishop Paul L
Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA.
Environ Pollut. 2005 Jan;133(1):117-27. doi: 10.1016/j.envpol.2004.05.020.
A series of adsorption experiments was conducted in order to assess the ability of three mulches to remove several of the heavy metal ions typically encountered in urban runoff. Three types of mulch, cypress bark (C), hardwood bark (H), and pine bark nugget (P), were selected as potential sorbents to capture heavy metals in urban runoff. The hardwood bark (H) mulch had the best physicochemical properties for adsorption of heavy metal ions. In addition, because of its fast removal rate and acceptably high capacity for all the heavy metal ions, it was concluded that the H mulch is the best of the three adsorbents for treatment of urban runoff containing trace amounts of heavy metals. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. The sorption of these metals on H mulch conformed to the linear form of the Langmuir adsorption equation. At pH 5 and 6, the Langmuir constants (S(m)) for each metal were found to be 0.324 and 0.359 mmol/g (Cu); 0.306 and 0.350 mmol/g (Pb); and 0.185 and 0.187 mmol/g (Zn) at 25 degrees C.
为了评估三种覆盖物去除城市径流中几种常见重金属离子的能力，进行了一系列吸附实验。选择了三种覆盖物，即柏树皮（C）、硬木树皮（H）和松树皮块（P），作为捕获城市径流中重金属的潜在吸附剂。硬木树皮（H）覆盖物对重金属离子的吸附具有最佳的物理化学性质。此外，由于其对所有重金属离子的去除速度快且容量较高，得出结论，H覆盖物是三种吸附剂中处理含微量重金属的城市径流的最佳选择。为了研究吸附等温线，分析了两种平衡模型，即Freundlich等温线和Langmuir等温线。这些金属在H覆盖物上的吸附符合Langmuir吸附方程的线性形式。在25℃下，在pH值为5和6时，每种金属的Langmuir常数（S(m)）分别为0.324和0.359 mmol/g（铜）；0.306和0.350 mmol/g（铅）；以及0.185和0.187 mmol/g（锌）。
