This study demonstrated high-efficient dye adsorption for wastewater using MoS 2 -glue sponge as an easy-separative and regenerative adsorbent. Flower-like molybdenum disulfide (MoS 2 ) nanopowders with rich polar edge sites were firstly synthesized by a facile one-pot hydrothermal method . Chemical and morphological features of MoS 2 nanoflowers were then examined by XRD , XPS , SEM and TEM . Afterwards, different concentrations of the MoS 2 -glue sponges with easy separability were successfully fabricated by a convenient two-step dip-coating method. The adsorption performance was estimated by the removal of Rhodamine B (RhB) dyes. The results proved that the maximum adsorption capacity of MoS 2 -glue sponge was 127.39 mg RhB/g product in 60 min. The RhB uptake behaviors can be well described by the Sips isotherm model and pseudo-second-order kinetic model , indicating a multilayer and chemical adsorption process. The adsorption mechanism proposed that the zwitterionic RhB molecules in aqueous solution would aggregate on the surface of negative charged MoS 2 in a head-to-tail way through electrostatic interaction . Furthermore, RhB dyes could desorb easily from MoS 2 -glue sponges when changing the polarity of solvent and the reusability experiment showed that the MoS 2 -3% glue sponge could be reused for 15 times with above 85.8% of the adsorption capacity retained. Thus, the novel MoS 2 -glue sponge is considered as a competitive adsorbent for treatment of dyestuff waste water.
Zhi Liu,Xiaohai Huang,Yi Miao,Bing Gao,Yiling Shi,Jianghui Zhao,Soon Huat Tan
Adsorption techniques have been successfully applied in water purification for their simplicity, efficiency, and negligible byproducts. Porous carbon materials are effective dye adsorbents but have relatively low adsorption efficiency, slow adsorption rate, and high production cost, all of which need to be addressed for conducive practical applications. Herein, natural eggplant-based porous carbon materials (EPCMs) have been studied and successfully constructed to perform with high efficiency and fast rate of removal of dyes from wastewater. The hierarchical pore structure and well-developed mesoporous had a total pore volume of 0.6379 cm 3 /g and a maximum specific surface area of 516.0060 m 2 /g, which contributed to the high efficiency of adsorption (100%). The complete adsorption of Rhodamine B (basic and cationic dyes) solution within 25 min demonstrated its fast and high adsorption performance. The EPCMs also showed its efficiency in the absorption of various dyes, including methyl orange (acidic and anionic dye), methylene blue (basic and cationic dyes), and Yuan’qing B (reactive dye). Furthermore, the EPCMs were tested with actual wastewater from a production-based factory and recorded excellent removal effects as well, suggesting its prospective expansion for industrial applications. Therefore, this eggplant biomass-based porous carbon provides a promising approach for fast and highly efficient wastewater purification from dye-based contaminations.
The traditional polyvinyl alcohol composite hydrogel exhibited poor swelling and mechanical properties, which limited its application. To solve these issues, we use biomass lignin as raw material, PVA as matrix template and epichlorohydrin as cross-linker to prepare the Lignin-PVA super-absorbent hydrogels with the swelling ratio of up to 456 g/g under mild condition. When the lignin concentration was increased from vacancy to 5%, the swelling ratio of the Lignin-PVA hydrogels was increased from 92 g/g to 456 g/g. The lignin-based hydrogel synthesized by the higher molecular weight PVA showed better swelling performance. Softwood lignin, hardwood lignin and corncob lignin could also be used to fabricate the Lignin-PVA super-absorbent hydrogels with the swelling ratio of higher than 500 g/g. However, the optimum amount varied from different lignin types, which was related to the molecular weight and phenolic hydroxyl content of lignin. The structural mechanism of the Lignin-PVA hydrogel was proposed to clearly certify the enhancing role of lignin. The adsorption capacity of the Lignin-PVA hydrogel with respect to rhodamine 6G, crystal violet and methylene blue dyes was up to 196, 169 and 179 mg/g, respectively. The Lignin-PVA hydrogel presents great potential applications in the fields of soil water retention and seed cultivation in agriculture, and dye pollutant removal.
危险品化学品经营许可证（带存储）