Researchers from Nanjing University in China have developed an effective oil separation technique to remove oil — spilled from sources such as ships, offshore drilling operations and pipeline leaks — from wastewater.

According to the researchers, the new method for separating oil-water mixtures relies on solar thermal energy. By using solar energy, the technique can reportedly separate two-phase mixtures with little environmental impact. Further, the method will work on virtually any oil-contaminated seawater surface with sunlight.

Graphical abstract. Source: Higher Education Press

The researchers suggest that other benefits of the technology include the ability to simultaneously produce electricity, high oil removal efficiency nearing 100% and long-term stability.

Making this possible is the inclusion of a wood absorber, which is carbonized and demonstrates appropriate light adsorption capability, according to the researchers. The end product has been designed by applying the Janus structure, which is commonly used in oil and water separation applications.

In the lab, the Janus wood absorber demonstrated what the researchers suggest was an “excellent” oil removal rate.

The research is detailed in the article, "Solar evaporation for simultaneous oil-water separation and electricity generation with Janus wood-based absorbers," which appears in the journal Frontiers of Environmental Science & Engineering.