Study On Removal Of Triclosan From Aqueous Solution By Adsorption Of Various Activated Carbons

Triclosan(TCS),as the representative of PPCPs,can disturb the endocrine system of the human body,and the harm is serious.The paper investigated the removal and adsorption behavior of TCS in water on various activated carbon.According to the influence of different factors on the adsorption process,and combined with the characterization results of the physicochemical properties of activated carbons,the action mechanism of TCS adsorption by activated carbon was analyzed,at the same time,the dynamic penetration experiment was simulated.In this research,the adsorption behavior studies showed that the adsorption of TCS on three activated carbon(AC)W20,830,F20 was balanced at 48 h,40h and 48 h,respectively,and The adsorption behaviors of TCS on the three ACs were followed the pseudo-second-order kinetic model.The adsorption of TCS on the three ACs fitted to the Langmuir model.The adsorption capacity of TCS on W20 was 386.84mg/g which was obviously higher than on 830(278.11mg/g)and F20(234.23mg/g).Study on influence factors showed that the adsorption capacity of activated carbon increased with the increase of concentration about TCS.It was improved that the ability of TCS transferred from liquid phase to solid phase with the increasing of concentration about TCS,which increased the ability of TCS from solution to activated carbon,resulting in the adsorption capacity of TCS to be promoted.The adsorption capacity of activated carbon decreased with the increase of temperature.The adsorption of TCS on there ACs was a spontaneous exothermic process and mainly physical adsorption,which was accompanied by chemisorption.The change of the solution pH value may change the form of TCS and fine charge of ACs surface.With the increase of pH,the adsorption capacity of TCS on there ACs firstly increased and then decreased,and the optimum pH for TCS adsorption on W20 was 5(adsorption capacity was 401.46mg/g);accordingly,the optimum pH was 7 for 830(adsorption capacity was 285.72mg/g)and was 7 for F20(adsorption capacity was 239.65mg/g),respectively.Further studies showed that the introduction of ionic strength led to a decrease in the charge shielding in the solution,thereby,the electrostatic interaction was reduced between activated carbon and TCS.Meanwhile,the solubility of TCS in solution could be reduced by salting out,which could affect the adsorption of TCS on activated carbon.The adsorption capacity of TCS increased with the increase of ionic strength to some extent.Basing on the characterization results of surface properties of ACs and effects of different factors on the TCS adsorption,the ?-? dispersion interaction and physical adsorption could play the major role for the adsorption of TCS on the ACs surface.The research of column breakthrough curve indicated that the penetration time of three activated carbons was 84 h,68h and 72 h,respectively.The saturated adsorption capacities of TCS on three activated carbons was 615.79mg/g,280.47mg/g and 318.85mg/g,respectively.The adsorption capacity of TCS on W20 was still better than that of on the other two activated carbons.The adsorption capacity of W20 and 830 was higher than that of static test,while the adsorption capacity of 830 was decreased.