Fig. 1. A schematic diagram of rotating biological contactors (RBC). 1, Polycyclic aromatic hydrocarbon (PAH) contained wastewater tank; 2, effluent wastewater tank; 3, air condenser; 4, RBC reactor; 5, electrical motor; 6, air filter; 7, airflow meter; 8, air pump; 9, recycling water bath.