Oil and grease is defined as any material recovered as a substance soluble in extracting solvent. It can be composed of fatty matter from animal and vegetable sources and from hydrocarbons of petroleum origin. Oil and grease in water can cause surface films and shoreline deposits leading to environmental degradation, and can induce human health risks when discharged in surface or ground waters. Presence of excessive amounts may interfere with aerobic and anaerobic biological processes and lead to decreased wastewater treatment efficiency. Liquid-liquid partition by solvent extraction is the most widely used method for the determination of oil and grease.
