有机膨润土对溶液中阿莫西林的吸附性能研究

应用膨润土吸附阿莫西林,探讨了4种吸附剂的吸附效果,并以改性十六烷基三甲基铵盐(DK1)为试验材料,研究了吸附时间、溶液pH值、投加量、初始质量浓度和温度等因素对有机膨润土吸附溶液中阿莫西林效果的影响。结果表明,在自然pH值条件下,DK1的吸附剂效果最佳,且吸附在15min内快速达到平衡。吸附过程符合伪二级动力学方程,同时符合Freundlich、Langmuir和Temkin型等温吸附方程,是个吸热的过程,Langmuir理论最大吸附容量在30℃时可达27.86mg/g。对等温方程的研究表明,DK1对阿莫西林的吸附呈单分子层形式,吸附性能良好,易于进行。

Adsorptivity of amoxicillin from the aqueous solutions with organic bentonite

This paper is concerned about our research report of the adsorptivity of amoxicillin from the aqueous solutions with the help of organic bentonite.As a technical process,amoxicillin is a widely used in penicillin-like antibiotic,though its residue may have toxic impact on the algae and other lower organisms within the food chain.Adsorption,as a chemical process to remove contaminants from water and/or other liquids,has also been widely used in modern technology.So far as we know,of the four bentonites,DK1 modified with hexadecyl trimethyl ammonium is generally regarded as the most effective absorbent.The removal percentages of amoxicillin account for 97.9 and 13.8% for DK1 and NaB,respectively.More modified bentonite proves much more effective than unmodified one.The conditions influencing the adsorption of DK1 for amoxicillin may include the contact time,pH value,the initial concentration and temperature,dosage to be used,etc.The results of our batch adsorption experiments indicate that under the natural pH,the adsorption of DK1 can reach its equilibrium quickly in a period of time of 15 min,with pH being a crucial factor that may affect the adsorption.However,with the increase of amoxicillin and the dosage from 1 to 15 g/L,the adsorption capacity(qe) tends to decrease.The dynamic adsorption can well be described by the pseudo second-order-rate model at various temperatures,with the kinetic constant being 0.022 5 g/(mg·min).The adsorption process and data also prove to be in conformity with the Freundlich,Langmuir and Temkin adsorption isotherm.More exactly speaking,Langmuir isotherm suggests that the optimal adsorption capacities of 27.86 mg/g has been found at 30 ℃.The thermodynamic par suggests that the adsorption of amoxicillin onto DK1 was physisorptive,spontaneous and endothermic in nature.The adsorption is caused actually by the amoxicillin interactions with surfactant cations on the clay’s surface as well as within the clay interlayer space.Further elaboration can also be able to reveal a few more likely mechanisms for the adsorption systems.And,finally,it can be found that less than 5% of amoxicillin was desorbed from DK1,for organobentonites are good adsorbent and,therefore,its adsorptivity is both feasible in actual sewage purification and beneficial for the study of desorption and actual sewage treatment.