碱水热净水污泥吸附剂对氨氮的吸附性能  

Adsorption Properties of Ammonia Nitrogen by Alkali-hydrothermal Water Treatment Sludge Adsorbent

作　　者：何李文泽 陈钰 赵玉婷 李艳君 杨顺生[1] HE Liwenze;CHEN Yu;ZHAO Yuting;LI Yanjun;YANG Shunsheng(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学地球科学与环境工程学院,四川成都610031

出　　处：《水处理技术》2022年第10期82-87,共6页Technology of Water Treatment

基　　金：国家自然科学基金面上项目(51779211)。

摘　　要：以净水污泥为原料,外加氢氧化钠溶液,采用水热炭化法在不同温度、时间和碱含量下,制备出碱水热净水污泥吸附剂,并用于去除水中氨氮。通过正交实验结果得到,在水热温度210℃、氢氧化钠质量分数5%、反应时间6h条件下制备的吸附剂对氨氮吸附效果最好。采用SEM-EDS、BET、FTIR对吸附剂进行表征及解析,考察溶液pH、吸附时间、吸附剂投加量等因素对吸附性能的影响。结果表明,碱水热改性后硅铝比降低,钠元素含量提高,增加了阳离子交换容量。pH为中性时吸附效果最佳,升高温度更有利于吸附的进行。对实验数据进行动力学、等温模型拟合及热力学参数计算,发现吸附过程符合准二级动力学模型和Freundlich模型,对氨氮的吸附为吸热、熵增的自发反应,主要吸附机理为静电引力和阳离子交换。Using water treatment sludge as raw material and adding sodium hydroxide solution,the alkali-hydrothermal water treatment sludge adsorbent was prepared by hydrothermal carbonization method at different temperatures and times,and used to remove ammonia nitrogen from water.The results of orthogonal experiment showed that the adsorbent prepared under the conditions of hydrothermal temperature of 210℃,mass fraction of sodium hydroxide of 5%and reaction time of 6 h had the best adsorption effect on ammonia nitrogen.SEM-EDS,BET and FTIR were used to characterize and analyze the adsorbents.The effects of pH adsorption time and adsorbent dosage on the adsorption properties were investigated.The results show that the ratio of Si to Al decreases,the content of sodium increases,and the cation exchange capacity increases.When pH is neutral,the adsorption effect is the best,and increasing temperature is more conducive to the adsorption.The experimental data were fitted with kinetic and isothermal models and calculated with thermodynamic parameters.It was found that the adsorption process was in line with the quasi-second-order kinetic model and Freundlich model.The adsorption of ammonia nitrogen was a spontaneous reaction with endothermic and entropy increase,and the main adsorption mechanism was electrostatic attraction and cation exchange.

关 键 词：净水污泥 水热改性 氢氧化钠 氨氮 吸附 

分 类 号：TQ424[化学工程]