Adsorption and flotation in one step: A new method for treating petroleum wastewater

Developing process intensification technologies to treat Petroleum Wastewater (PW) is crucial to maintaining the economic and environmental safety of the process. Therefore, a one-step combination of adsorption and flotation was tested in this study for the first time to remove organic compounds from PW using a biochar-derived composite. High salinity PW samples from Brazilian oil wells were used to test the efficiency of the new method. The tests in synthetic petroleum wastewater found that applying the composite in the combined technique is an efficient alternative for removing organic compounds, presenting better results than using a commercial surfactant. In addition, applying the composite in real-petroleum wastewater showed that it can remove up to 83.89% of oil and grease concentration, even in complex and highly competitive environments. Therefore, its application in batch adsorption and in biosorptive flotation has technical and environmental potential as a viable alternative for treating produced water. [Display omitted] •An easy-to-separate composite was designed to be used in wastewater treatment.•The composite achieved 91.59% oil and grease removal via batch adsorption.•One-step adsorption and flotation method was proposed for produced water treatment.•The combined adsorption/flotation method obtained higher removal efficiency than the separated ones.•Produced water parameters significantly reduced after combined method application.