The Conventional Oil-Water Separator as A Polluter Due to Lack of Maintenance – A Case Study

In addition to the common knowledge that lack of maintenance of conventional oil-water separators causes release of excessive amounts of oil in the effluent wastewater, this study has revealed that excessive amounts of other pollutants are released alongside the oil. The disappearance of fishes from a stream in the Niger Delta after the continual discharge of the wastewater of a company prompted this study. The company has a conventional oil-water separator but no maintenance was done on it, five months after commissioning. Research methods include sampling of the effluent wastewater for a period of two weeks (ten working days) and analysis of the wastewater for pH, oil & grease content, total suspended solids, total dissolved solids, sulfate and chloride contents. Results showed that the concentration of total dissolved solids was consistently less than the regulatory limit but much higher than the concentration obtained at the commissioning of the separator. Results showed that the oil & grease content, chloride, sulfate and total suspended solids concentrations were consistently higher than the regulatory limits and also much higher than the concentrations obtained at the commissioning of the separator. Results showed that the pH values of the effluent wastewater were consistently outside the optimum range for survival of aquatic life. Monthly maintenance of the separator and further treatment of its effluent wastewater were recommended for protection of the environment and public health.