Competitive Adsorption Characteristics Of Sulfa Antibiotics In River Sediment

OECD Guideline batch equilibrium method were used in the expriment,studied the competitive adsorption characters for three antibiotics（SD、SMZ、SM₂）in the sediments of Daling Baishi Reservoir Bridge.The results showed that:in a single antibiotic component adsorption experiments,Langmuir model fit best for the three kinds of antibiotics thermodynamics.Fit for the three models of Langmuir、Freundlich、D-R for antibiotics in the sediment adsorption,By analyzing the judgment,Conducted that the three sulfa antibiotics adsorption isotherms on sediment are L-shaped thermal curve,Langmuir model fit the data best,By Langmuir model to predict the adsorption capacity of three antibiotics size relationship is SMZ>SD>SM₂;And the adsorption on the sediment of three antibiotics begin physical adsorption based.By analysis three sulfa antibiotics on sediment thermal dynamics,The results show that,Three antibiotics in the sediment adsorption Gibbs free energy change are all negative and entropy are positive;This shows that the adsorption of three antibiotics in the river sediment is a spontaneous reaction,And the antibiotices-sediments system were disordered with the process of adsorption.In the competitive expriment,Antibiotics in the sediment of the adsorption isotherm does not render conventional H,L,S,C four types of adsorption isotherms.It shows irregular,erratic changes.The adsorption of river sediment to sulfa antibiotic is selective.The adsorption performance of SMZ,SD is above the SM₂.By inductive analysis of antibiotic partition coefficient,Conducted that antibiotics adsorbed on the river sediment sequence is SMZ>SD>SM₂.