NaOH改性活性白土对低浓度氨氮的吸附研究  

Adsorption of low concentration ammonia nitrogen on modified activated clay by NaOH

作　　者：陈徐庆 唐玉朝[1] 伍昌年[1] 黄显怀[1] 薛莉娉[1] 王品之 王坤[1] 刘俊 张彬彬 CHEN Xu-qing;TANG Yu-chao;WU Chang-nian;HUANG Xian-huai;XUE Li-ping;WANG Pin-zhi;WANG Kun;LIU Jun;ZHANG Bin-bin(Anhui Key Laboratory of Environmental Pollution Control and Waste Resource Utilization,Anhui Jianzhu University,Hefei 230601,Anhui Privince,China;Anhui Zhonghuan Environmental Protection Technology Co.,Ltd.,Hefei 230001,Anhui Privince,China)

机构地区：[1]安徽建筑大学环境污染控制与废弃物资源化利用安徽省重点实验室,安徽合肥230601 [2]安徽中环环保科技股份有限公司,安徽合肥230001

出　　处：《化学工程》2022年第9期30-36,共7页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(51978003,51578002)。

摘　　要：以NaOH溶液对活性白土进行改性,研究改性白土对低浓度氨氮的吸附性能。使用扫描电镜、傅里叶红外光谱、Zeta电位对吸附剂的表征结构进行分析。考察了pH、投加量、接触时间对氨氮去除率的影响,研究了改性吸附剂对氨氮的吸附动力学、热力学、吸附等温线的特性,并对吸附机理进行探讨。结果表明:改性白土对氨氮的吸附符合准二级动力学模型。Langmuir吸附等温线模型能更好拟合改性白土吸附行为,拟合后的最大吸附量为5.4632 mg/g。改性后白土表面明显变得粗糙,孔径减小,氨氮吸附容量得到提升。当pH值为9.0,吸附剂投加量为2.5 g/L,吸附时间为2 h时效果最好,平衡时氨氮的吸附容量为5.2138 mg/g,去除率约为24%。傅里叶光谱表征了改性后的白土含有—OH,吸附后白土内部存在NH_(4)^(+)。Activated clay was modified with NaOH solution,and the adsorption performance of modified clay to low concentration ammonia nitrogen was studied.In the experiment,the characterization structure of the adsorbent was analyzed by scanning electron microscope,Fourier transform infrared spectroscopy and Zeta potential.The effects of pH,dosage and contact time on the removal rate of ammonia nitrogen were investigated.The adsorption kinetics,thermodynamics and adsorption isotherms of the modified adsorbent on ammonia nitrogen were studied,and the adsorption mechanism was discussed.The results show that the adsorption of ammonia nitrogen by modified clay conforms to the pseudo-second-order kinetic model.The Langmuir adsorption isotherm model can better fit the adsorption behavior of modified clay,and the fitted maximum adsorption capacity is 5.4632 mg/g.After the modification,the surface of the clay becomes obviously rough,the pore size is reduced,and the adsorption capacity of ammonia nitrogen is improved.When the pH value is 9.0,the dosage of adsorbent is 2.5 g/L,and the adsorption time is 2 h,the effect is the best.At equilibrium,the adsorption capacity of ammonia nitrogen is 5.2138 mg/g,and the removal rate is about 24%.Fourier transform shows that the modified clay contains—OH,and there is NH_(4)^(+) in the adsorbed clay.

关 键 词：活性白土 氨氮 吸附 NAOH 

分 类 号：X703[环境科学与工程—环境工程]