Spectroscopic investigation reveals the interference mechanism of surfactants on the removal of 1-naphthol by activated biochar

Removal of polycyclic aromatic hydrocarbons (PAHs) in treated wastewater by adsorbents is a simple and efficient method. However, most of investigations were focused on the adsorption of single pollutant, and little is known about the interference of coexisted pollutants, especially the ubiquitous surfactants. In this study, the interference mechanism of surfactants on biochar adsorption performace to 1-naphthol was investigated by fluorescence spectrum coupling X-ray photoelectron spectroscopy analysis. Although the adsorption performance of activated biochar cannot be hindered by low concentration of surfactant (10 mg/L) both in synthetic and real wastewater, high concentrations of surfactant significantly inhibit the adsorption performance of activated biochar. Fluorescence spectra suggested that a new complex may form by the interaction of SDBS and 1-naphthol, although it could not be structurally identified, which does impede the adsorption of 1-naphthol. Competition of surfactants for the active sites on the adsorbent and replacement of the adsorbed 1-naphthol are other effective factors.