Wang Xiao-Ling, Qiao Bin, Li Song-Min, Li Jian-Sheng
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300072, China.
School of Environment Science and Engineering, Tianjin University, Tianjin, 300072, China.
Environ Sci Pollut Res Int. 2016 Mar;23(6):5342-51. doi: 10.1007/s11356-015-5743-5. Epub 2015 Nov 13.
The potential of natural Chinese zeolite to remove ammonium from rainfall runoff following urea applications to a paddy rice field is assessed in this study. Laboratory batch kinetic and isotherm experiments were carried out first to investigate the ammonium adsorption capacity of the natural zeolite. Field experiments using zeolite adsorption barriers installed at drain outlets in a paddy rice field were also carried out during natural rainfall events to evaluate the barrier's dynamic removal capacity of ammonium. The results demonstrate that the adsorption kinetics are accurately described by the Elovich model, with a coefficient of determination (R (2)) ranging from 0.9705 to 0.9709, whereas the adsorption isotherm results indicate that the Langmuir-Freundlich model provides the best fit (R (2) = 0.992) for the equilibrium data. The field experiments show that both the flow rate and the barrier volume are important controls on ammonium removal from rainfall runoff. A low flow rate leads to a higher ammonium removal efficiency at the beginning of the tests, while a high flow rate leads to a higher quantity of ammonium adsorbed over the entire runoff process.
本研究评估了天然中国沸石在稻田施用尿素后从降雨径流中去除铵的潜力。首先进行了实验室批量动力学和等温线实验，以研究天然沸石对铵的吸附能力。在自然降雨事件期间，还在稻田排水口处使用沸石吸附屏障进行了田间实验，以评估屏障对铵的动态去除能力。结果表明，吸附动力学可以用埃洛维奇模型准确描述，决定系数（R²）在0.9705至0.9709之间，而吸附等温线结果表明，朗缪尔-弗伦德利希模型对平衡数据的拟合效果最佳（R² = 0.992）。田间实验表明，流速和屏障体积都是降雨径流中铵去除的重要控制因素。低流速在测试开始时导致较高的铵去除效率，而高流速在整个径流过程中导致较高的铵吸附量。
