Natural superhydrophobic/superoleophilic Juncus effusus pith separation column with ordered porous network structure for rapid and efficient oil/water separation

Abstract

Oily wastewater and oil spills have adverse impacts on aquatic ecosystems and even the human environment. Developing highly efficient nonfluorinated superoleophilic separation materials for oil/water separation is urgently needed. Herein, a natural Juncus effusus pith was directly used as a raw material to prepare novel separation columns via a facile compression strategy. The pith possessed natural superoleophilicity (oil contact angle almost 0°) with inherent oleophilic properties and regular multilayer, porous, network structure. These pith characteristics endowed related separation columns with superior oil selectivity. The pore size of the prepared columns was controlled by adjusting the degree of compression. In this strategy, the separation efficiency the column reached up to 99.99 and 97.7% for eight types of oil/water mixtures and surfactant-stabilized emulsions under gravity, respectively. After repeated column recycling, these columns retained excellent separation performance and the separation mechanism was investigated. No new pollutants and hazardous substances were introduced into the environment in column fabrication and separation processes. Therefore, this study provided the basis for an ecofriendly, low-cost, and scalable strategy for reasonable utilization of natural biomaterials with superoleophilicity, thus exhibiting great potential for the rapid treatment of oil spillage and industrial oily wastewater.