Zheng Wen-Jing, Lin Jian-Wei, Zhan Yan-Hui, Fang Qiao, Yang Meng-Juan, Wang Hong
College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China.
Huan Jing Ke Xue. 2013 Nov;34(11):4325-32.
Surfactant-modified activated carbon (SMAC) was prepared by loading cetylpyridinium chloride (CPC) onto activated carbon and used as adsorbents to remove nitrate from aqueous solution. The SMAC was effective for removing nitrate from aqueous solution. The SMAC exhibited much higher nitrate adsorption capacity than that of the unmodified activated carbon. The nitrate adsorption capacity for SMAC increased with increasing the CPC loading. The adsorption kinetics of nitrate on SMAC followed a pseudo-second-order kinetic model. The equilibrium adsorption data of nitrate on SMAC could be described by the Langmuir isotherm model. Based on the Langmuir isotherm model, the maximum nitrate adsorption capacity for SMAC with CPC loading amount of444 mmol per 1 kg activated carbon was determined to be 16.1 mg x g(-1). The nitrate adsorption capacity for SMAC decreased with the increasing solution pH. The presence of competing anions such as chloride, sulfate and bicarbonate reduced the nitrate adsorption capacity. The nitrate adsorption capacity for SMAC slightly decreased with the increasing reaction temperature. Almost 95% of nitrate molecules adsorbed on SMAC could be desorbed in 1 mol x L(-1) NaCl solution. The main mechanisms for the adsorption of nitrate on SMAC are anionic exchange and electrostatic attraction. The results of this work indicate that SMAC is a promising adsorbent for removing nitrate from aqueous solution.
通过将十六烷基吡啶氯化物（CPC）负载到活性炭上制备了表面活性剂改性活性炭（SMAC），并将其用作吸附剂以从水溶液中去除硝酸盐。SMAC对从水溶液中去除硝酸盐是有效的。SMAC表现出比未改性活性炭更高的硝酸盐吸附容量。SMAC的硝酸盐吸附容量随着CPC负载量的增加而增加。硝酸盐在SMAC上的吸附动力学遵循准二级动力学模型。硝酸盐在SMAC上的平衡吸附数据可以用Langmuir等温线模型来描述。基于Langmuir等温线模型，对于每1千克活性炭CPC负载量为444 mmol的SMAC，其最大硝酸盐吸附容量被确定为16.1 mg x g(-1)。SMAC的硝酸盐吸附容量随着溶液pH值的增加而降低。诸如氯离子、硫酸根离子和碳酸氢根离子等竞争阴离子的存在降低了硝酸盐吸附容量。SMAC的硝酸盐吸附容量随着反应温度的升高而略有降低。吸附在SMAC上的硝酸盐分子几乎95%可以在1 mol x L(-1) NaCl溶液中解吸。硝酸盐在SMAC上吸附的主要机制是阴离子交换和静电吸引。这项工作的结果表明，SMAC是一种从水溶液中去除硝酸盐的有前景的吸附剂。
