Grass-modified graphene aerogel for effective oil-water separation

• Published in: Process safety and environmental protection 2019-09, Vol.129, p.119-129
• Main Authors: Song, Yan, Li, Huihui, Gao, Yue, Yue, Qinyan, Gao, Baoyu, Kong, Wenjia, Zang, Yanan, Jiang, Wenqiang
• Format: Article
• Language: English
• Subjects: Adsorption; Aerogels; Contact angle; Environmental cleanup; Filter media; Graphene; Graphene aerogel; Grass-modified; Grasses; Heat treatment; Hydrophobicity; Hydrothermal treatment; Oil; Oil-water separation; Oils & fats; Performance enhancement; Recoverability; Regeneration; Selective adsorption; Selectivity; Separation; Thermal stability; Water purification
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2019.06.018

[Display omitted] •GGA was fabricated by a facile, green and low-cost method.•GGA exhibits ultralight, good thermostability, excellent hydrophobicity.•GGA shows good selectivity, high adsorption capacities and recoverability.•Oil-water separation can be achieved by GGA in different manipulation ways.•Biomass waste was used to treat pollutants achieving waste utilization. Grass-modified graphene aerogel (GGA) was successfully fabricated via simple, low-cost and environment-friendly hydrothermal treatment. The samples exhibited porous structure, low density of 6.99mg/cm3, good thermostability, excellent hydrophobicity with water contact angle of 146°. The properties of graphene aerogel have been significantly improved by introducing grass powder, leading to highly efficient selective adsorption. The adsorption capacity of GGA ranged from 68.40 to 145.84g/g for various liquid solvents, which is superior to that of unmodified graphene aerogel (GA). Moreover, GGA can be regenerated by repeated heat treatment and its adsorption capacity maintaining at above 90% of initial value after regeneration. GGA can realize oil-water separation of mixed solution by different manipulation methods. On one hand, GGA removed little oils in water through adsorption. On the other hand, GGA can act as filter media dealing with oil-water mixtures and collecting oils continuously by gravity or peristaltic pump. Good selectivity, high adsorption capacities and satisfactory recoverability make it possible to become a potential candidate in the field of oil-water separation and spill oil cleanup to realize environmental remediation. In the meantime, the incorporation of grass improves the performances of graphene aerogel in hydrophobicity, mechanical property and oil adsorption efficiency, providing a new path for high-value utilization of biomass waste.