Magnetic carboxyl functional nanoporous polymer: synthesis, characterization and its application for methylene blue adsorption.

ABSTRACT

Magnetic carboxyl functional nanoporous polymer (MCFNP) was chemically fabricated by incorporation of magnetic Fe3O4 precursor into the carboxyl functional nanoporous polymer (CFNP). The as-synthesized MCFNP was characterized and used as an adsorbent for rapid adsorption removal of methylene blue (MB) from wastewater. Several experimental parameters affecting the adsorption efficiency were investigated including initial pH, adsorbent dosage, initial MB concentration, contact time and temperature. The adsorption behavior of MCFNP displayed that adsorption kinetics and isotherms could be well fitted to the pseudo-second-order and Langmuir models, respectively. The experimental results showed that MCFNP was an effective adsorbent with a maximum adsorption capacity of 57.74 mg g-1 for MB at 298 K. The negative free energy (ΔG) and positive enthalpy change (ΔH) confirmed that the adsorption reaction was a spontaneous and endothermic process. In addition, ethanol was used as an effective extractant for the regeneration of MCFNP, and the adsorption efficiency could remain 80% after the ninth regeneration cycle.