# Development and Performance Study of Continuous Oil–Water Separation Device Based on Superhydrophobic/Oleophilic Mesh

## TL;DR

This paper presents a new device for efficiently separating oil and water using superhydrophobic mesh, achieving high separation efficiency and long-term stability.

## Contribution

The study introduces a novel superhydrophobic/oleophilic mesh-based device for continuous oil–water separation with optimized structural and process parameters.

## Key findings

- Single-stage and two-stage oil–water separation efficiencies reached 92.79% and 98.96%, respectively.
- The multi-channel device maintained high separation efficiency (94.60% and 98.76%) after 36 hours of continuous operation.
- The modified stainless mesh retained superhydrophobic properties for 34 days with a contact angle above 150°.

## Abstract

Oil–water separation is an important method for treating oily wastewater and recovering oil resources. Based on the different affinities of superhydrophobic surfaces to water and oil, long-term oil–water separation devices with low-energy and high efficiency can be developed through the optimization of structure and process parameters. Superhydrophobic coatings were prepared on stainless-steel mesh surfaces using a spray method to construct single-channel oil–water separation equipment with superhydrophobic/oleophilic meshes, and the effects of structural and process parameters on separation efficiency were systematically investigated. Additionally, a multi-channel oil–water separation device was designed and fabricated to evaluate the feasibility and stability of long-term continuous operations. The optimized single V-shaped channel should be horizontally placed and made from 150-mesh stainless-steel mesh folded at an angle of 38.9°. For the oil–water mixtures containing 20 wt.% oil, the oil–water separation efficiencies for single and two-stage separation were 92.79% and 98.96%, respectively. After 36 h of continuous operation, the multi-channel separation device achieved single-stage and two-stage separation efficiencies of 94.60% and 98.76%, respectively. The maximum processing capacity of the multi-channel device reached 168 L/h. The modified stainless mesh can remain stable with a contact angle (CA) higher than 150° to water for 34 days. The average residence time and contact area during the oil–water separation process significantly affect separation efficiency. By optimizing oil–water separation structures and process parameters, and using a superhydrophobic spray modification method, separation efficiency can be improved while avoiding the generation of secondary pollutants.