EDW generally contains a small amount of crude oil, inorganic salt, sulfide, phenol, suspended particles, organic matter, and other chemicals such as demulsifier. The sidetrack experiment of removing oil from EDW was conducted in an oil refinery. The treated EDW had an oil concentration of 4000–60,000 mg/L and temperature range of 50–90 C. The kinematic viscosity of crude oil was 476.1mm2/s (50 1C). The other main properties are listed in