An efficient superhydrophobic sludge-based activated char sponge for oil/ water separation

The recyclability and environmental friendliness of sponge-based materials for oil/water separation have attracted considerable attention recently. This study presents a proof-of-concept experiment by modifying a melamine sponge (MS) surface with superhydrophobic sludge-based activated char (AC) for oil/water separation. An easy dip-coating technique was used to embed the superhydrophobic nanomaterial into the MS threedimensional (3D) structure. In the absence of further surface modification and pretreatments, the sponge showed high oil uptake abilities. For different types of oils, absorption capacities of 120-180 times the coated-MS (CMS) weight were achieved in fresh and simulated seawater with only a slight pH dependence. Comparatively to previous studies, CMS had a low loading percentage of 6 wt% and a more recyclable function. The present work offers a relatively facile, cost-effective, and green strategy for fabricating efficient absorbent materials to meet the needs of oil spill cleanup and recovery.