Adsorptive Removal Of Antibiotics From Water Using XAD-4 Resin

In our country,extensive applications of antibiotics are in line with increasing ecologicalrisks.Aimingatthetypicalantibiotics(tetracycline(TCN),sulfamethoxazole(SMX)and amoxicillin(AMX)).The adsorption behaviors on macroporous resins XAD-4 were studied in this paper,which could provide theoretical supports in treating and recycling antibiotics wastewater.The main study contents were listed as follows:The results of static adsorption kinetics showed the adsorption data of tetracycline,sulfamethoxazole and amoxicillin antibiotics were fitted to the pseudo-second-order kinetic model by nonlinear regression(R~2>0.99),indicating the pore size was the main effect on the adsorption rate,the more initial solution concentration is,the more initial reaction rates are.At 25 degrees centigrade,the adsorption data of tetracycline,sulfamethoxazole and amoxicillin antibiotics were fitted to the Langmuir model by nonlinear regression(R~2>0.99),indicating the adsoptions of tetracycline,sulfamethoxazole and amoxicillin antibiotics are monolayer adsorption.Maximum adsorption capacity of TCN,SMX and AMX antibioticsbyXAD-4resinsis133.071,142.414,96.129mg/g,respectively.ComparedwithGAC,XAD-4resinshasahigher removal efficiency for SMX and AMX.The effect of solution chemistry on the adsorption behavior and mechanism had been studied by static adsorption experiments in this paper:(1)the effect of pH:it was found that the higher percentages of neutral species in the solution,the more adsorption capacity of TCN,SMX and AMX on the adsorbents,which indicated the contribution of force between the molecules(such as?-?-EDA interaction,hydrophobic effects)was stronger than those between the functional groups on the adsorption process;(2)the effect of ion concentration:adsorption capacity of TCN,SMX and AMX on the adsorbents increased with the rise of sodium ions.this might largely result from the well-known salting out effect and electrostatic interactions.(3)the effect of humic acid:adsorption amount of TCN,SMX and AMX on the adsorbents slightly increased with the concentration of humic acid,when the concentration of humic acid rises to 100 mg/L,the adsorption amount of TCN,SMX and AMX on the adsorbents have no obvious increase,indicating macroporous resins XAD-4 have good anti-contamination performance.(4)Regeneration:The XAD-4resin could be easily regenerated by 2 mol/L NaCl solution and maintained high adsorption removal for TCN,SMX and AMX after repeated use of seven times.Thus,the high adsorption capacity,fast adsorption rate and prominent reusability make the macroporous resins XAD-4 a potential adsorbent in the application for removing antibiotics from water?...