Removal of Monoethylene Glycol from Gas Field Wastewater Using Aspergillus tubingensis and a New Bioreactor

Abstract

Monoethylene glycol (MEG) is used in the oil and gas industry to prevent freezing along well-to-refinery natural-gas transmission lines. Once the gas reaches the refinery, the MEG is then separated from the gas. In this process MEG is introduced to the refinery wastewater, making it extremely polluted and hazardous to the aquatic environment. Therefore, it is important to remove this substance from refinery wastewaters. This study examined the use of a microorganism in a glass reactor to remove MEG from wastewater generated at South Pars Gas Field Phase 4, Bushehr, Iran. A novel reactor satisfying the experimental conditions was built. The microorganism Aspergillus tubingensis was isolated from wastewater containing MEG and identified using a polymerized chain reaction buffer. The microorganism was fixed on a packed bed and transported to the glass reactor. Sampling and measurements of chemical oxygen demand (COD), pH values, and MEG concentration were performed at different periods. After 240 h, a 65 % decrease in COD was achieved and MEG concentration was reduced by more than 40 %.