On the Characteristic of Polycyclic Aromatic Hydrocarbons Emission and Removal in the Petroleum Refining Process

Through the method of sampling inspection, this article studied emission and elimination characteristic of EPA 16 kinds Polycyclic Aromatic Hydrocarbons (PAHs) in petroleum refining wastewater. The analysis shows: concentrations, components and emissions quantity of PAHs in refining wastewater of different units vary significantly. Catalytic cracking unit and delayed coking unit are major sources of wastewater PAHs generation and emission. The mass concentration of catalytic cracking unit emission is 1076~1179g/L, while of delayed coking unit is 87~681g/L, accounted for 54% and 27% of the total emissions respectively. The PAHs components in the refining units and sewage treatment units are following same pattern: low rings PAHs, such as fluorine, acenaphthylene, phenanthrene are the most predominates, which concentration accounted for 83% of the total components concentration. The removal rates of wastewater PAHs reduces along the sewage treatment process, which decreased gradually from 40% to 7.5%. The removal rate of high rings PAHs was 95%, which was higher than 90% removal rate of low rings PAHs.