Maize straw decorated with sulfide for tylosin removal from the water

Abstract

MS-ZnS and MS-ZnS:Mn complexes were synthesized via a simple method. The results showed that sulfide was successfully loaded on the maize straw. The results of fitting the experimental data showed that the sorption conforms to the pseudo-second-order kinetics, and the TYL sorption on MS fit the Henry model well, but the Freundlich model was more suited to MS-ZnS and MS-ZnS:Mn. In addition, the k_f values of MS-ZnS (206.0(mg/kg)/(mg/L)ⁿ) and MS-ZnS:Mn (382.5(mg/kg)/(mg/L)ⁿ) were significantly greater than that of MS (72.2(mg/kg)/(mg/L)ⁿ), indicating that ZnS and ZnS:Mn could improve the sorption capacity of TYL on MS. The pH, ionic strength and temperature influence the sorption process, and the sorption ability of TYL on MS-ZnS and MS-ZnS:Mn showed little change when the solution pH was > 5; the amount of TYL sorption on the adsorbents gradually decreased with the increasing concentration of KNO₃. Electrostatic interactions, H bonding and hydrophobic interactions are involved in the sorption of TYL on MS, MS-ZnS and MS-ZnS:Mn, and compared with MS, the main mechanism is surface complexation. This research can provide technical support for the utilization of biomass and the restoration of water polluted by antibiotics.

Keywords: Maize straw; Sorption; Sulfide; Tylosin.