Abstract: The distribution characteristics of organic pollutants in condensate water from blow blowdown tower of delayed coking unit were studied by using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). 340 kinds of hydrocarbons, 144 kinds of nitrogenous organic compounds, 69 kinds of organic-sulfur compounds, and 60 kinds of oxygen-containing organic compounds have been identified, which accounted for 60.20%, 11.77%, 15.42% and 8.09%, respectively. Among them, aromatic hydrocarbons (especially polycyclic aromatic hydrocarbons, such as pyrenes, benzanthracenes, naphthalenes and phenanthrenes) account for the largest proportion; nitrogenous organic compounds are mainly aromatic heterocyclic structures (pyridines, quinolines, indoles, carbazoles, pyrimidines, etc.) and aromatic amines; organosulfur compounds are mainly sulfur-containing heterocyclic structures and the sulfur-containing polycyclic aromatic hydrocarbons (benzothiophenes, benzonaphthothiophenes, dibenzothiophenes, phenanthrothiophene, naphthothiophenes, etc.) predominate; and phenols are the main oxygen-containing organic compounds. The organic pollutants (aromatic hydrocarbons, nitrogenous aromatic heterocyclic compounds, sulfur-containing heterocyclic compounds and phenols) have stable molecular structure, high toxicity and poor biodegradability.

Key words: delayed coking, wastewater, emulsification, organic pollutant, heterocyclic compound, pyridine, thiophene, phenol