An expanding horizon: Recyclable dual-functional size-adjusted fluorinated mesh devices for large-scale oily wastewater remediation

The general lack of water resources makes the treatment of oily wastewater as an urgent concern, which causes catastrophic damage to ecosystems and environment. Construction of a universal oil/water separator is not an easy task, because the reported processes are relatively complex and it is difficult to achieve industrial large-scale production. To overcome this problem, herein, using the low-cost and frequently-used metal (stainless steel, etc.) meshes as raw materials, two kinds of oil/water separators with different moving models have firstly designed via a universal technique of a facile chemical etching and fluoridation coating process. The newly synthesized superhydrophobic/superoilphilic stainless steel or copper mesh with surface morphology, high purity and structure stability displayed an excellent anti-wetting property (high water contact angle of >157 degrees) after a series of tests of immersion, droplet rolling-off, anti-impacting process, 30days exposure aging in open-air, etc. In addition, experimental results revealed that the fresh and aging separators can maintain excellent oily wastewater remediation efficiency up to similar to 99% even after 25 separation cycles, making them economical and commercially viable. This study provides a novel perspective for advancement in designing oil/water separator with low cost, less energy consumption and high efficiency for universal application.

Automated summary

The lack of water resources and the urgent need for oily wastewater treatment have caused catastrophic damage to ecosystems and the environment. However, the construction of a universal oil/water separator is challenging due to complex processes and difficulties in achieving large-scale production. To address this issue, this study designed two types of oil/water separators using low-cost metal meshes as raw materials. The newly synthesized stainless steel or copper mesh displayed excellent anti-wetting properties and maintained high oily wastewater remediation efficiency even after repeated separation cycles, making them economically viable for widespread application.