ABSTRACT
These petroleum products are made from crude oil through a refining process. During the refining process, petroleum refineries unavoidably generate large amounts of oily wastewater. These wastes occur at different stages of oil processing, such as during production, transportation and refining. However, during the production phase large amounts of oily wastes are generated, which become mixed with the sea water and cause pollution. Coelho et al. (2006) reported that the quantity of water used in the oil refinery processing industry during the production stage ranges from 0.4 to 1.6 times the volume of processed oil, and this wastewater may, if untreated, cause serious damage to the environment.
