Simultaneous removal of PAHs and metal contaminants from water using magnetic nanoparticle adsorbents

Many industrial wastewaters are contaminated with both heavy metal ions and organic compounds, posing a major threat to public health and the environment. In this study, magnetic nanoparticle adsorbents, namely Mag-PCMA-T, which contain a maghemite core and a silica mesoporous layer that permanently confines surfactant micelles within the mesopores, were synthesized to achieve simultaneous removal of polycyclic aromatic hydrocarbons (PAHs) (1mg/L) and metal contaminants (1mg/L). The individual removal efficiency of Cd(2+) and acenaphthene using Mag-PCMA-T was evaluated under a range of initial ion concentrations and adsorbent dosages, as well as the competitive adsorption with Cd(2+) and acenaphthene simultaneously present. The isotherms and kinetics of Cd(2+) and acenaphthene sorption onto Mag-PCMA-T were determined. Mag-PCMA-T removed >85% of the acenaphthene in <30min, with relatively high sorption capacity (up to 1060mg/kg). Mag-PCMA-T also exhibited high sorption capacity for Cd(2+) (up to 2250mg/kg). The simultaneous sorption performance was stable across a wide pH range (4-9) as well as in the presence of competitive metal ions (Ca(2+) and Mg(2+)) or natural organic matters. The Mag-PCMA-T can be regenerated and reused, providing a sustainable, fast, convenient, and efficient approach for water treatment.