Characterization and assessment of process water from oil and gas production: A case study of process wastewater in Qatar

This study characterized and assessed three different process water (PWWs) (S-1, S-2, and S-3) from oil and gas production in Qatar. The wastewater generated in various processing stages contains many harmful components including polyaromatic hydrocarbons, phenol, heavy metals, ammonia, and other hydrocarbons and non-hydrocarbons. The results revealed that S-2 had higher pH (8.5) followed by S-3 (8.3) and S-1 (7.8). Lastly, S-1 reported the highest concentration of gasoline range organics (GRO) and extractable petroleum hydrocarbons (EPH), and polycyclic aromatic hydrocarbons (PAHs) followed by S-2 and S-3. In addition, biological oxygen demand (BOD) was the highest in S-1 44,300 mg/L followed by S-2 and S-3 26,300 and 14,600 mg/L, respectively. Moreover, salinity was also the highest in S-3 at 260 ppt, followed by S-2 at 38.2 ppt and S-1 at 38.9. Overall, S-1 reported the highest concentration of GRO, EPH, and all PAHs followed by S-2 and S-3. Additionally, the PWWs consisted of high organic containing wastes. The results also revealed that all three PWWs were enriched with zinc and iron, and sixteen different hydrocarbon compounds were identified, amongst which acenaphthene, acenaphthylene, fluorene, anthracene, phenanthrene, benzo(a)anthracene, and pyrene were dominating in all three samples.