A hydrophilic surface molecularly imprinted polymer on a spherical porous carbon support for selective phenol removal from coking wastewater

A novel hydrophilic surface molecularly imprinted polymer from bi-functional monomers on a porous carbon nanosphere support (AMPS-Am/MIP) was prepared to improve the selective adsorption capacity towards phenol from coking wastewater using hydrophilic 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and acrylamide (Am) as the monomers, and phenol as the imprinting molecule. The surface morphology, functional groups, thermal stability and hydrophilicity of AMPS-Am/MIP were investigated, and the adsorption properties including kinetics, isotherms, selectivity and regeneration were tested. Results showed that the adsorption of AMPS-Am/MIP towards phenol in water reaches equilibrium in 180 min and the highest adsorption capacity was 96.59 mg g^-1. Its selection factor for phenol is as high as 1.67 in the presence of structural analogs, quinoline and hydroquinone. The adsorption capacity remained above 80% of the initial adsorption value after five adsorption-regeneration cycles. When the pH value of the phenol-containing water was around 8, close to that of coking wastewater, the adsorption capacity reached 46.84 mg g^-1, indicating the applicability and high efficiency of AMPS-Am/MIP for phenol adsorption in alkaline coking wastewater.