In Situ Fenton Triggered PDA Coating Copper Mesh with Underwater Superoleophobic Property for Oily Wastewater Pretreatment

Abstract

The issue of oily wastewater treatment has become a worldwide challenge due to increasing industrial oily wastewater and frequent oil spill accidents. As an integral part of practical sewage treatment, pretreatment is conducted to remove inorganic particles, floating oil, and some emulsified oil, and to pave the way for post-treatment. Here, we report a facile fabricated, hydrostable, and rapid underwater-formed superoleophobic copper mesh with polydopamine (PDA) coating for efficient oily wastewater pre-treatment. Unlike with traditional technologies, using the interface phenomenon to solve the problem of oil/water mixture separation provided a new approach for the low energy input pretreatment process. The PDA coating formed by the in situ Fenton method not only rapidly constructs a protection layer for the etched hierarchical micro-size particles on mesh and results in enhanced hydrophilicity, but also exhibits high uniformity and enhanced stability in acid/alkali medium. Benefiting from the above processes, a very high flux of 25 L m−2 s−1 and high separation efficiency of 99.0% toward various oil/water mixtures were achieved, revealing excellent prospects for practical usage. Therefore, this new approach offered insight into the development of a cost-effective and functional method for efficient pretreatment of oily wastewater.