OPW contains a complex mixture of

The water stream originated has a typical oil content varying from 0.02 to 0.2% w/w. This stream is usually treated by hydrocyclones and dissolved gas flotators, which are unable to remove suspended particles with particle size below 5.0 μm, as well as rarely reach the water quality for reinjection in terms of the suspended solids and O&G content (Li and Lee, 2009). The majority of Brazilian reservoirs require less than 5 mg L−1 for both parameters.