Cleanup of oils and organic solvents from contaminated water by biomass-based aerogel with adjustable compression elasticity

• Published in: Water research (Oxford) 2023-04, Vol.232, p.119684-119684, Article 119684
• Main Authors: Ding, Shaoqiu, Han, Xinhong, Zhu, Lingjun, Hu, Hanyu, Fan, Liwu, Wang, Shurong
• Format: Article
• Language: English
• Subjects: Adsorption; Biomass; Biomass-based aerogels; Carbonization; Compression elasticity; Elasticity; Oils - chemistry; Photothermal conversion; Polymorphic oil cleanup; Solvents; Water - chemistry
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2023.119684

•Citric acid crosslinking and carbonization contribute to compression elasticity.•CS6CA-300 exhibits high absorption capacities of 40‒125 g g−1.•The upper surface temperature of CS6CA-300 reaches 70 °C within 60 s under 1 sun.•Excellent photothermal effect promotes absorption up to 56 g g−1 for crude oil. Leakage of oils and organic solvents poses a significant threat to aquatic environments. Here, low-temperature carbonized aerogels with highly porous and anisotropic structures obtained only from biomass-derived materials were proposed to absorb polymorphic oils from contaminated water. Specifically, carbonized aerogels prepared at temperatures of 300 °C and 350 °C exhibited ultra-high absorption capacities (40‒125 g g−1) and oil-water separation efficiencies (> 99%) even in harsh environments, which were attributed to their exceptional properties, including high porosity, abundant macropores, excellent thermal stability, and hydrophobicity. Through citric acid crosslinking and low-temperature carbonization, the aerogels exhibited superior compression elasticity and could be cyclically utilized through simple extrusion while realizing the recovery of oils. Moreover, the outstanding photothermal conversion properties obtained through carbonization contributed to the high temperature and fluidity of the oils surrounding the aerogels, which is crucial for improving the absorption performance of high-viscosity oils. Such absorbent materials are used to separate crude oil from oil-water mixtures, which can achieve maximum absorption of 56 g g−1 and increase the absorption rate (from several days to 10 min) in a low-temperature (4 °C) seawater environment. [Display omitted]