Insight into the adsorption of tetracycline onto amino and amino–Fe functionalized mesoporous silica: Effect of functionalized groups
Ziyang Zhang
,
Haiyan Li
,
Huijuan Liu
DOI:10.1016/j.jes.2016.10.020
Received August 07, 2016,Revised October 13, 2016, Accepted October 26, 2016, Available online March 18, 2017
Volume 30,2018,Pages 171-178
In order to study the influences of functionalized groups onto the adsorption of tetracycline (TC), we prepared a series of amino and amino–Fe3 + complex mesoporous silica adsorbents with diverse content of amino and Fe3 + groups (named N,N-SBA15 and Fe-N,N-SBA15). The resulting mesoporous silica adsorbents were fully characterized by X-ray powder diffraction, Fourier transform infrared spectrometer and N2 adsorption/desorption isotherms. Furthermore, the effects of functionalized groups on the removal of TC were investigated. The results showed that the periodic ordered structure of SBA-15 was maintained after modification of amino/Fe3 + groups. The functionalized amino groups decreased the adsorption capacity while the coordinated Fe3 + increased the adsorption capacity. The adsorption kinetics of TC fitted pseudo-second-order model well and the equilibrium was achieved quickly. The adsorption isotherms fitted the Langmuir model well and with the Fe3 + content increased from 3.93% to 8.26%, the Qmax of the adsorbents increased from 102 to 188 mmol/kg. The solution pH affected the adsorption of TC onto amino complex adsorbents slightly while influenced the adsorption onto Fe-amine complex adsorbents greatly. The adsorption of TC on SBA15 and N,N-SBA15 may be related to the formation of outer-sphere surface complexes, while the adsorption of TC onto Fe-N,N-SBA15 was mainly attributed to the inner-sphere surface complexes. This study could offer potential materials that have excellent adsorption behavior for environmental remediation and suggested useful information for the preparing other adsorbents in environmental applications.
