氯化十六烷基吡啶改性活性炭对水中硝酸盐的吸附作用  

Removal of Nitrate from Aqueous Solution Using Cetylpyridinium Chloride ( CPC)-Modified Activated Carbon as the Adsorbent

作　　者：郑雯婧 林建伟[1] 詹艳慧[1] 方巧[1] 杨孟娟[1] 王虹[1] 

机构地区：[1]上海海洋大学海洋科学学院,上海201306

出　　处：《环境科学》2013年第11期4325-4332,共8页Environmental Science

基　　金：国家自然科学基金项目(50908142);上海市科学技术委员会科研项目(10230502900);上海高校青年教师培养资助计划项目(ZZhy12012);上海市教委重点学科建设项目(J50702);长江水环境教育部重点实验室开放基金项目(YRWEF201107)

摘　　要：采用阳离子表面活性剂氯化十六烷基吡啶(CPC)对活性炭进行了改性,并通过实验考察了CPC改性活性炭对水中硝酸盐的吸附作用.结果表明,CPC改性活性炭对水中的硝酸盐具备较好的吸附能力.CPC改性活性炭对水中硝酸盐的吸附能力明显高于未改性的活性炭.CPC改性活性炭对水中硝酸盐的吸附能力随着CPC负载量的增加而增加.CPC改性活性炭对水中硝酸盐的吸附动力学满足准二级动力学模型.CPC改性活性炭对水中硝酸盐的吸附平衡数据可以较好地采用Langmuir等温吸附模型加以描述.根据Langmuir等温吸附方程,CPC负载量(以活性炭计)为444 mmol·kg-1的改性活性炭对水中硝酸盐的最大单位吸附量为16.1 mg·g-1.CPC改性活性炭对水中硝酸盐的吸附能力随着pH的增加而降低.水中共存的氯离子、硫酸根离子和碳酸氢根离子会抑制CPC改性活性炭对水中硝酸盐的吸附.升高反应温度略微降低了CPC改性活性炭对水中硝酸盐的吸附能力.采用1 mol·L-1的NaCl溶液可以使95%左右吸附到CPC改性活性炭上的硝酸盐解吸下来.CPC改性活性炭吸附水中硝酸盐的主要机制是阴离子交换和静电吸引作用.上述实验结果说明,CPC改性活性炭适合作为一种吸附剂用于去除水中的硝酸盐.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 of 444 mmol per 1 kg aetivated carbon was determined to be 16.1 mg.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. L-I NaC1 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.

关 键 词：氯化十六烷基吡啶改性活性炭 硝酸盐 吸附 再生 

分 类 号：X131.2[环境科学与工程—环境科学]