Removal of ciprofloxacin and carbamazepine by adsorption on inorganic porous materials

Abstract

Ciprofloxacin (CIP) and Carbamazepine (CBZ) are widely used pharmaceutical products for treatment of many symptoms. It was reported that they are persistent and can be detected from several water sources. The discharged CIP and CBZ in environment can affect to microorganism or aquatic ecology even for very low concentration; therefore, the elimination of CIP and CBZ from water has to be investigated. The objectives of this research were to study the adsorption of CIP and CBZ by using synthesized hexagonal mesoporous silicate (HMS), functionalized HMSs, SBA-15, and superparamagnetic magnetite, comparing with powdered activated carbon (PAC). The results showed that mercapto functional groups grafted on HMS provided highest CIP and CBZ adsorption capacities; however, it was still lower than that of PAC. The saturation time of HMSs and PAC were achieved at 9 hr, while 3 hr for SBA-15 and superparamagnetic magnetite. The kinetic results were compatible with pseudo-second order. The hydrophobicity and hydrogen bonding might play a key role on the adsorption. Furthermore, the capacities were impacted by varying pH values due to the strength of hydrogen bonding between targeted compounds and adsorbents. The adsorption capacities of both CIP and CBZ on the studied adsorbents were fitted with Langmuir isotherm model implying that the adsorption phenomena of the targeted compounds were monolayer adsorption.