POLYNUCLEAR AROMATIC COMPOUNDS IN COAL AND OIL SHALE WASTEWATER: AN ENVIRONMENTAL CONCERN

A solvent refining coal liquefaction process recycle water (No. 3) from Du Pont, Washington, a true in-situ oil shale retort water (Omega-9) from Rock Springs, Wyoming, and a ten-ton unit simulated in-situ oil shale retort water (No, 16) from Laramie, Wyoming, were subjected to solvent extraction procedure and subsequent instrumental analysis including: (a) high performance liquid chromatography (HPLC) of polynuclear aromatics (PNA's) having more than four rings; (b) capillary gas chromatography (GC) of low molecular weight volatile PNA's; and (c) gas chromatography-mass spectrometry (GC-MS) for complementary identification of PNA's having functional and heterocyclic modifications.A total of 41 PNA's were identified. Identification of 28 PNA's in the coal derived water (No. 3) was attained, whereas that of the true in-situ retort water (Omega-9) and the simulated retort water (No. 16) were 24 and 18, respectively. Thirteen PNA's were found to be common to all three wastewater samples. Thirteen PNA's were exclusively found in sample No. 3 whereas that of samples Omega-9 and No. 16 were 8 and 4, respectively. It was estimated that the concentration of PNA's in all samples ranged from traces to 30.0 ppb.