Department of Civil, Environmental, and Construction Engineering, University of Central Florida, Orlando, FL, USA.
Department of Civil, Environmental, and Construction Engineering, University of Central Florida, Orlando, FL, USA.
Environ Pollut. 2020 Nov;266(Pt 1):115172. doi: 10.1016/j.envpol.2020.115172. Epub 2020 Jul 13.
Recycled materials were used in three types of green sorption media for nutrient removal and possible recovery in high nutrient-laden agricultural discharge and stormwater runoff. The three types of green sorption media included in this comparative study were two new aluminum-based green environmental media (AGEM) and one existing iron-filings based green environmental media (IFGEM). The corresponding adsorption isotherm, thermodynamics, and kinetics models were simulated based on isotherm studies to determine their removal efficiency and potential for recovery of nitrate, phosphate, and ammonia when used as a soil amendment in crop fields or in a filter for water treatment. AGEM-2 exhibited the shortest contact time required to achieve nutrient removal above 80% with an average of 7 h, followed by AGEM-1 and IFGEM with 10.6 and 28 h, respectively. Natural soil was included as a control and exhibited minimal nutrient removal. Ammonia, which may be recovered as fertilizer for drop fields in a soil-water-waste nexus, was generated by all three green sorption media mixes, therefore indicating their potential for use as soil amendments in agricultural and forested land after engineering filter applications. The kinetics analysis indicated that nitrate adsorption follows pseudo-first-order kinetics, while phosphate adsorption follows pseudo-second-order kinetics. The Gibbs free energy indicated that most of the adsorption reactions proceeded as exothermic. Lastly, a few equilibrium models, including the Langmuir, Freundlich, First Modified Langmuir, Temkin, Jovanovic, and Elovich models, were ranked and three were selected for use with IFGEM, AGEM-1, and AGEM-2, respectively, as below: (1) Langmuir, (2) Freundlich, and (3) First Modified Langmuir, according to three indices.
在高营养负荷农业排放和雨水径流中，三种类型的绿色吸附介质均使用了再生材料，以去除营养物质并可能进行回收。在这项比较研究中，三种绿色吸附介质包括两种新型铝基绿色环境介质（AGEM）和一种现有的铁粉基绿色环境介质（IFGEM）。根据等温研究模拟了相应的吸附等温线、热力学和动力学模型，以确定它们作为农田土壤改良剂或水处理过滤器时去除硝酸盐、磷酸盐和氨的效率以及回收的潜力。AGEM-2 表现出最短的接触时间，达到 80%以上的养分去除所需的平均时间为 7 小时，其次是 AGEM-1 和 IFGEM，分别为 10.6 和 28 小时。天然土壤作为对照，表现出最小的养分去除。所有三种绿色吸附介质混合物均产生氨，氨可作为水土废物共生体中滴灌田的肥料回收，这表明它们在工程过滤应用后作为农业和林地土壤改良剂的潜力。动力学分析表明，硝酸盐吸附遵循准一级动力学，而磷酸盐吸附遵循准二级动力学。吉布斯自由能表明，大多数吸附反应是放热的。最后，对包括 Langmuir、Freundlich、First Modified Langmuir、Temkin、Jovanovic 和 Elovich 模型在内的几种平衡模型进行了排序，并根据以下三个指标，分别为 IFGEM、AGEM-1 和 AGEM-2 选择了三个模型：（1）Langmuir，（2）Freundlich 和（3）First Modified Langmuir。
