An evaluation of oily wastewater treatment by a pilot scale land treatment system

摘要

A common waste by-product of metal fabrication industries is a dilute oil in water emulsion. In this study, an oil in water emulsion (0.5percent) is generated by an aluminum rolling mill from a coolant used to dissipate heat during the hot rolling fabrication process. This wastewater is collected in two lined ponds where free oil separates from the wastewater and is periodically removed. The pond effluent, with an oil and grease concentration varying between 500 to 5000 mg/L, is sprayed onto an non-vegetated unlined land treatment system where optimum degradation of the oil and grease by indigenous microorganisms occurs in the top 6" of soil. The hydraulic loading rate to this system is 0.5 inches per week. Impending groudnwater regulations have alerted the aluminum rolling mill to the need to seek alternative treatment. A pilot-scale study was instituted to evaluate five technologies on removal of oil and grease from this wastewater. Lined land treatemnt was one of these technologies. The principal objective of the research was to evaluate the performance of a vegetated (V) and nonvegetated (NV) lined land treatment system on oil and grease (O/G) removal.