The Study On Environmental Behavior Of Tetracycline Antibiotics In Different Texture Soils

Tetracycline antibiotics abuse leads to the low concentration of antibiotics in environment.Antibiotics can induce antibiotic resistance genes,which is a potential threat to the ecological security.Soil is the main warehouses of the antibiotics,as well as the inevitable path of the migration into the water environment.The paper is inclined to reveal the adsorption,desorption and migration process of tetracycline(TC)and oxytetracycline(OTC)in three types of soils from different soil texture.The results indicate below:(1)The results show that,the adsorption and desorption of tetracycline antibiotics in clay,loam and sandy soil can all be divided into two stages: fast adsorption balance and slow phase.There was significant difference between TC and OTC for the adsorption behavior in the same soil.For the three different texture soils,the adsorption capacity is in the order: loam > clay>sandy soil.(2)For TC and OTC,they can all be best described by the Freundlich model in the three different texture soils.There have obvious desorption hysteresis constant between TC and OTC for the adsorption behavior in the same soils.Without organic matter,the adsorption ability of OTC in soil is reduced.The result of pH for tetracycline antibiotics adsorption in soils has a dual role.(3)TC has more strong vertical migration in the different texture soils than OTC.There is the most obvious migration effect on the sand for TC and OTC.Increasing the concentration of the antibiotics and the leaching velocity can accelerate the migration of antibiotics in soils.(4)In simulating rainfall conditions,migrated antibiotic partly flows away with runoff and sediment,others penetrates into the soil.The antibiotic in the runoff of three texture soils show a law of increasing firstly,then declining and finally stable.Total loss in runoff of three texture soils show a trend of sandy soil> clay > loam.