Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran E-mail:
Center for Social and Behavioral Sciences Research, Shahroud University of Medical Sciences, Shahroud, Iran.
Water Sci Technol. 2020 Jan;81(2):358-366. doi: 10.2166/wst.2020.116.
Ammonia nitrogen levels are very high in leachate. This study was conducted to optimize the removal of ammonia nitrogen from fresh landfill leachate using a combination of ultrasound waves and ultraviolet irradiation. A sample of fresh landfill leachate was obtained from a municipal landfill site, located in Shahroud (Semnan, Iran) and its ammonia nitrogen was measured by spectrophotometric method. Ultrasound and ultraviolet irradiation were simultaneously used to remove ammonia nitrogen. Box-Behnken design (BBD) based on response surface method (RSM) was applied to analyze and optimize ammonia nitrogen removal by different variables, including pH, contact time, ultrasound frequency and UV intensity. Based on this method, 29 samples with three replications were tested. The analysis of variance indicated quadratic model was significant for removal of ammonia nitrogen from leachate. According to the model, 99.7% removal efficiency (%) of ammonia nitrogen was obtained in the optimal conditions (pH at 9.7, contact time of 59.1 min, ultrasound frequency of 54 kHz and UV intensity of 40 W). The removal efficiency of ammonia nitrogen was obtained 98.6% from the laboratory experiment in these conditions, which agrees well with the predicted response value.
渗滤液中的氨氮含量很高。本研究旨在通过超声波和紫外线辐射联合作用，优化新鲜垃圾渗滤液中氨氮的去除。从位于伊朗 Semnan 的 Shahroud 市的一个城市垃圾填埋场获得了新鲜的垃圾渗滤液样品，并通过分光光度法测量其氨氮含量。同时使用超声波和紫外线辐射来去除氨氮。基于响应面法（RSM）的 Box-Behnken 设计（BBD）用于分析和优化不同变量（包括 pH 值、接触时间、超声波频率和 UV 强度）对氨氮去除的影响。根据该方法，共测试了 29 个具有三个重复的样本。方差分析表明，二次模型对渗滤液中氨氮的去除具有显著意义。根据该模型，在最佳条件下（pH 值为 9.7、接触时间为 59.1 分钟、超声波频率为 54 kHz 和 UV 强度为 40 W），氨氮的去除效率达到 99.7%。在这些条件下，实验室实验中氨氮的去除效率达到 98.6%，与预测的响应值吻合较好。
