3种四环素类抗生素在石油污染土壤上的吸附解吸

以OECD Guideline 106为基础,采用批量平衡方法研究了3种四环素类抗生素在不同石油污染程度土壤上的吸附和解吸作用,并探讨了土壤中此类抗生素与石油污染物形成的复合污染环境行为.结果表明,3种四环素类抗生素在高石油污染和低石油污染土壤上的吸附和解吸均不同程度地偏离线性模型,其中Freundlich模型对吸附和解吸数据具有良好的非线性拟合性(P四环素>金霉素,差异达到极显著水平(P<0.01).对于同一种四环素类抗生素,石油污染土壤的不同程度并未对抗生素的吸附容量、吸附强度、吸附等温线形状、吸附机理以及解吸滞后性产生显著影响.因此四环素类抗生素进入石油污染土壤将加重土壤污染的程度和复杂性.

Adsorption and desorption of three tetracycline antibiotics in petroleum-contaminated soils

On the basis of the OECD Guideline 106,batch adsorption methods were employed to reveal the adsorption and desorption process of three tetracycline antibiotics in petroleum-contaminated soils.The Freundlich model was the best isotherm to describe all experimental data of adsorption and desorption(P<0.01).In petroleum-contaminated soils,chlortetracycline adsorption isotherms resembled S-type curves,oxytetracycline adsorption isotherms resembled the L-type curves,and tetracycline adsorption isotherms resembled the linear curves according to adsorption strength(1/n value).The three antibiotics had strong adsorption in petroleum-contaminated soils,and the adsorption capacity(lgKf) was in the order of chlortetracycline(4.168 and 4.514) > tetracycline(2.975 and 2.771) > oxytetracycline(2.340 and 2.337).The dominant mechanism of three tetracycline antibiotics adsorption was physical adsorption in petroleum-contaminated soils.HI was in the order of oxytetracycline > tetracycline > chlortetracycline with significant difference(P<0.01).For same antibiotic,the petroleum-contaminated extent could not affect the adsorption and desorption of three antibiotics in soil.Thus soil pollution would be greatly increased and complicated with the antibiotic occurring in petroleum-contaminated soils.