Journal of Hebei University(Natural Science Edition) ›› 2023, Vol. 43 ›› Issue (4): 395-407.DOI: 10.3969/j.issn.1000-1565.2023.04.008

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Periodic changes for adsorption of methyl oranges on natural hydrotalcite by online method

YE Jianhua1,YU Tao1,YU Haoqi1,LIU Huiyu1,YUAN Xueyan2   

  1. 1.School of Nuclear Science and Engineering, East China University of Technology, Nanchang 330013, China; 2. School of Chemical Biology and Materials Science, East China University of Technology, Nanchang 330013, China
  • Received:2022-07-12 Online:2023-07-25 Published:2023-08-03

Abstract: In order to study the periodic change law of adsorbance behavior of pollutants in water on adsorbent surface, explore the dynamic change mechanism of adsorption and desorption, and improve the adsorption efficiency, the online adsorption experiment was carried out by using the home-made online spectrophotometer, combined with the online measurement results of pH and electrical conductivity of adsorption system. The kinetic and thermodynamic properties of the adsorption of methyl orange on natural hydrotalcite were explained. Based on theoretical calculations, the equation of the periodic variation of adsorption was proposed and deduced. The 721 spectrophotometer was modified for the online determination of the real-time changes of adsorbent concentration in the adsorption system; the optimal online adsorption condition was determined by the experiment condition at pH 3.5 and solid-liquid ratio of 0.002 g/L, and the adsorption rate under this condition reached 83.6%. The online adsorption experiments- DOI:10.3969/j.issn.1000-1565.2023.04.008甲基橙在天然水滑石上的在线吸附周期性规律研究叶剑华1,于涛1,余豪奇1,刘会誉1,原雪燕2(1.东华理工大学 核科学与工程学院,江西 南昌 330013;2.东华理工大学 化学生物与材料科学学院,江西 南昌 330013)摘 要:为研究水体中的污染物在吸附剂表面吸附性行为的周期性变化规律,探讨吸附-解吸的动态变化机理,提高吸附效率,采用改造的分光光度计进行在线吸附实验,结合吸附体系pH、电导率的在线测定结果,解释了甲基橙在天然水滑石上的吸附动力学、热力学特性.根据理论计算,提出并推导出吸附周期性变化规律公式.通过改造的721分光光度计,在线测定吸附体系中吸附质浓度的实时变化;通过条件实验确定最佳在线吸附条件为pH 3.5,吸附剂质量浓度0.002 g/L,在此条件下的吸附率达83.6%.在线吸附实验显示,天然水滑石对甲基橙的在线吸附过程中,前10 min吸附率持续增长,10~15 min吸附率增长趋于平稳,15~20 min吸附率变化呈指数衰减,符合指数衰减规律.此后吸附量随接触时间的变化呈现出潮汐波动现象.此潮汐波动呈周期性变化,且变化周期受温度和浓度影响较小,每个周期的变化符合指数增长规律.关键词:甲基橙;天然水滑石;吸附;周期性变化;动力学中图分类号:X52 文献标志码:A 文章编号:1000-1565(2023)04-0395-13Periodic changes for adsorption of methyl oranges on natural hydrotalcite by online methodYE Jianhua1,YU Tao1,YU Haoqi1,LIU Huiyu1,YUAN Xueyan2(1.School of Nuclear Science and Engineering, East China University of Technology, Nanchang 330013, China; 2. School of Chemical Biology and Materials Science, East China University of Technology, Nanchang 330013, China)Abstract: In order to study the periodic change law of adsorbance behavior of pollutants in water on adsorbent surface, explore the dynamic change mechanism of adsorption and desorption, and improve the adsorption efficiency, the online adsorption experiment was carried out by using the home-made online spectrophotometer, combined with the online measurement results of pH and electrical conductivity of adsorption system. The kinetic and thermodynamic properties of the adsorption of methyl orange on natural hydrotalcite were explained. Based on theoretical calculations, the equation of the periodic variation of adsorption was proposed and deduced. The 721 spectrophotometer was modified for the online determination of the real-time changes of adsorbent concentration in the adsorption system; the optimal online adsorption condition was determined by the experiment condition at pH 3.5 and solid-liquid ratio of 0.002 g/L, and the adsorption rate under this condition reached 83.6%. The online adsorption experiments- 收稿日期:2022-07-12 基金项目:国家自然科学基金资助项目(21561001);江西省自然科学基金资助项目(20202BABL203004) 第一作者:叶剑华(1998—),男,云南曲靖人,东华理工大学在读硕士研究生,主要从事环境放射化学方向研究. E-mail:2513172134@qq.com 通信作者:于涛(1979—),男,吉林白城人,东华理工大学副教授,博士,主要从事环境放射化学方向研究.E-mail:xiaoshan770@163.com第4期叶剑华等:甲基橙在天然水滑石上的在线吸附周期性规律研究showed that the adsorption rate of natural hydrotalcite on methyl orange continued to increase in the first 10 min, and then stabilized from 10 to 15 min and declined exponentially from 15 to 20 min, which was in accordance with the exponential decay law. After that, the adsorption amount showed a tidal fluctuation with the contact time. The tidal fluctuation was cyclical, and the cycle of change was less affected by temperature and concentration, and the change of each cycle was in accordance with the exponential growth law.

Key words: methyl orange, natural hydrotalcite, adsorption, periodic change, kinetics

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