摘要
针对低温微污染水中(7℃)低质量浓度As(Ⅲ)/As(Ⅴ)离子(0.5 mg/L),通过优化配煤、改进制备工艺制备,制备一种中孔型活性炭(NCPAC),以普通商品活性炭PVAC为对照,研究了NCPAC的表面物理化学特性,并进行了pH影响和吸附等温线、吸附动力学方程及吸附热力学拟合研究.结果表明,NCPAC的孔径分布、总孔容积和表面极性大小等方面均得到改善.在酸性/偏中性范围内(pH=4.0~8.0),NCPAC对As(Ⅲ)、As(Ⅴ)均有较好的去除效果,除砷效果明显高于普通商品活性炭.NCPAC对As(Ⅲ)/As(Ⅴ)的吸附平衡可用Langmuir进行较好的拟合;动力学研究表明NCPAC对As(Ⅲ)/As(Ⅴ)的吸附过程可用假二级动力方程进行很好的拟合(R2>0.999),且As(Ⅲ)/As(Ⅴ)在活性炭表面的吸附过程以化学吸附为主;热力学数据显示,NCPAC对As(Ⅲ)、As(Ⅴ)的吸附过程均为放热反应.共存离子方面,天然水体中常见的磷酸氢根、硅酸根、碳酸根对NCPAC除砷效果有一定的抑制作用,铝离子会降低其对As(Ⅲ)的吸附效果,其他阴阳离子对除砷效果影响不大.
An innovative mesoporous activated carbon（ NCPAC） using optimizations of coal-blending and preparation procedure were developed for effective removal of arsenic from drinking water. Compared with the ordinary commercial activated carbon（ PVAC）,the surface chemical and physical properties of NCPAC was measured,and effects of pH,adsorption isotherms,kinetics,thermodynamic were investigated at 7 ℃. The results showed that the pore structure distribution,total pore volume and surface polarity etc. of NCPAC were improved. NCPAC could remove arsenic more efficiently than PVAC,and the removal of arsenic occurred in a wide range of p H as examined from 4. 0 to 8. 0. Adsorption of As（ Ⅲ）/As（Ⅴ） on NCPAC better matched the Langmuir adsorption model. The Pseudo-second-order model described adsorption kinetics well（ R2 0. 999） indicating that chemical adsorption was rate-controlling step in adsorption process of As（ Ⅲ）/As（Ⅴ） on NCPAC.The thermodynamic study indicated that the adsorption of As（ Ⅲ） and As（Ⅴ） was a spontaneous and exothermic process. The presence of phosphate,carbonate and silicate could significantly decrease arsenic removal,while the effects of other ions were minimal.
作者
公绪金
GONGXu-jin(School of Energy and Civil Engineering,Harbin University of Commerce,Harbin 150028,China)
出处
《哈尔滨商业大学学报（自然科学版）》
CAS
2018年第3期300-306,314,共8页
Journal of Harbin University of Commerce：Natural Sciences Edition
基金
国家自然科学基金资助项目(51708162)
关键词
活性炭
吸附
砷
深度活化
配煤
共存离子
activated carbon
adsorption
arsenic
depth - steam - activation
coal blending
co - existing ions
