Efficient adsorbent based on construction and demolition wastes functionalized with 3-aminopropyltriethoxysilane (APTES) for the removal ciprofloxacin from hospital synthetic effluents

Abstract

An inorganic sludge from construction and demolition wastes (ICDW) was grafted with APTES to obtain an inorganic-organic modified adsorbent ICDW-APTES. This adsorbent was successfully employed for ciprofloxacin (CFX) adsorption and treatment of synthetic hospital effluent. The chemical composition of ICDW presented large quantities of SiO2 and Al2O3, which supports its application for being functionalized by APTES that occurred through a chemical reaction between the surface oxygen groups of oxides with the silanol groups of the APTES. The characterization data suggested that APTES was successfully grafted on the ICDW structure. The kinetic studies showed that the general-order provided the best fitness for CFX adsorption on ICDW-APTES. Liu isotherm model presented the best fitness for the equilibrium studies, and it provided a Qmax of 138.0 mg g−1 at 40.0 °C. Electrostatic interaction was the primary mechanism involved in the adsorption process. The ICDW-APTES also exhibited a good percentage of removal of the two synthetic effluents (71.0 % and 69.0 %).