Research On The Adsorption&Degradation Mechanism Of Tetracyclines In The Clay Minerals

Recently,a new series of pollutants attract people's attention including POPs,PTs,PBTs,EDCs.The pollutants are harmful to the ecosystem and body though they exist in trace in the environment.Antibiotics is a kind of important trace pollutants with the character of wide usage,increasing amount and projected harm.In China,the amount of livestocks'faeces is huge and the chance of enter into the farmland is increasing,thus will be also affected.Tetracyclines?TCs?is the widely used antibiotics,it is of large probability to affect the agricultural products such as cereal,vegetable and fruits.Research on the absorption mechanism of TCs is useful to lucidate the law of the adsorption behavior of TCs in the environment and to get new technology to remove the TCs from the environment.Presently,the research on the TCs focused on the exsit,concentration and its'absorption,desorption and migration in the soils.there are also initial interest in the degradation and environmental toxicology though it is not systematic.Based on the current situation,the thesis begin our research specially in the adsorption mechanism,find the key function of hydroxyl group in the study of clay adsorption of TC using High Performance Liquid Chromatography?HPLC?and spectrophotometry?SP?,firstly confirm the adsoption-facilitated rule of hydroxyl group in TC through Infrared Spectroscopy and Thermogravemetric adsorption.Furthermore,we apply the conclusion in the degradation of TC through catalytic reaction on the Magnetic Sludge Carbon,explain the molecular mechanism of TC's adsorption and the variation of-OH,the main conclusions are as below:?1?The thesis take TC as object,study the structure variation under different surroundings in the laboratory simulation.Results show that in the same pH,the adsoption ability of Oxytetracycline?OTC?,TC and Aureomycin?AM?is deceasing one by one,NH₄⁺can promote the content of Anhydro-tetrcycline while K⁺has slightly effect on the TCs with different structure.The findings reveal that TCs with different structure change its'adsorption ability mainly because of its'R group of side chain,the adsorption ability in acid surroundings is stronger than in alkaline surroundings in normal;?2?The thesis research on the adsoption behavior in clay minerals and the variation of its'main group in the adsorption,taking Montmorillonite?Mont.?and Kaolin?Kao.?as main adsorption medium.Results show that hydroxyl group of side chain can promote adsorption through formation of H bond,the amount and location of hydroxyl group is the important factor affecting adsorption behavior??3?To explain the effect of hydroxyl group in the adsorption behavior furtherly,the thesis design the degradation test using Magnetic sludge carbon as catalyst.The findings show that the amount and formation of HO·can promote the degradation of TC,More and more HO·is formed,the degradation degree is higher.The results show the similar role of hydroxyl group in adsorption behavior.The thesis conduct correlative research between the group variation and adsorption/degradation behavior,find that–OH can promote the adsorption and degradation.The change of surroundings related variation of hydroxyl group can affect the adsorption significantly.The adsorption behavior of TCs also changes with the change of the amount&locatin of hydroxyl.The conclusion afford theory support to the remove and degradation of TCs.