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In this study, high-purity cellulose nanofibrils (CNFs) were environmentally friendly extracted from natural bamboo. Physical, chemical, and mechanical treatments were comprehensively investigated, and then ensembled to effectively and efficiently remove lignin and hemicellulose with low energy from raw bamboo fibers, which combine microwave liquefaction, hydrogen peroxide-acetic acid delignification, alkaline treatment, and along with acid hydrolysis. This was able to allow for the extraction of CNFs. Compositional analysis, Fourier-transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis were performed to investigate and confirm the successful removal of undesirable lignin and hemicellulose. The resultant cellulose fibers were then subjected to a mechanical treatment to obtain the cellulose nanofibrils. It was found that the obtained CNFs have an average diameter of 13 nm with a cellulose purity of 94.52%. Without any further surface modification, the incorporation of bamboo-based CNFs into natural rubber (NR) exhibits significant improvement in their mechanical properties including modulus (~66.67%), tensile strength (~120.83%), toughness (~139.34%), and elongation at break (~31.41%). Interestingly, there is no compromise between tensile strength and elongation at break for the nanocomposites. DMA results also showed that both storage and loss moduli were dramatically enhanced over those of neat NR in their glassy region, which is typically unusual. This study can show, if optimized for material extraction, the great promise to the potential use of natural materials to develop environmentally friendly composites with multi-functionality in a variety of real-world engineering structural applications. [ABSTRACT FROM AUTHOR]

Recently, MXenes have attracted considerable attention owing to their unique physical and chemical properties. Construction of MXenes to three-dimensional (3D) porous aerogel structures can play a critical role in realizing the profound implications of MXenes, especially for environmental remediation. Nevertheless, developing mechanically robust MXene-based aerogels with reversible compressibility under harsh conditions, such as liquid environments, remains challenging due to the insufficient interfacial strength between MXene nanosheets. Herein, 3D porous MXene-based nanocomposite aerogels are developed by dual physical and chemical crosslinking strategy with poly(vinyl alcohol) and formaldehyde in this study. The developed MXene-based nanocomposite aerogels with designed interfacial engineering exhibit outstanding structural stability and extremely high reversible compressibility up to 98% strain as well as unprecedented mechanical durability (2000 cycles at 50% strain) in water environment. Moreover, the aerogels show adaptable compressibility when exposed to different solvents, which is explained with the Hansen solubility parameter. Thanks to their high compressibility in water, the robust MXene-based aerogels exhibit excellent methylene blue adsorption performance (adsorption capacity of 117.87 mg·g−1) and superior recycling efficiency (89.48% at the 3rd cycle). The porous MXene-based nanocomposite aerogels are also demonstrated with outstanding thermal insulation capability. Therefore, by synergistically taking their porous structure and super elasticity in liquid environment, the MXene-based aerogels show great promise in diverse applications including adsorption and separation, wastewater purification desalination, and thermal management. [ABSTRACT FROM AUTHOR]

Natural manganese ore (NM) is selected as a distinguished constructed wetland (CW) substrate for nutrient pollutants removal, however, the study on municipal wastewater treatment plant (WWTP) effluent treatment remains scarce. The current study was to investigate the sorption characteristics of NM and the removal efficiency of ammonium and phosphorus from one WWTP effluent in a simulated vertical flow NM constructed wetland (NM-VFCW). Results indicated that NM could effectively sorb ammonium and phosphorus within 24 h, and the desorption ratio was less than 7%. The sorption of ammonium and phosphorus enhanced when increasing the particle size of NM, but was not sensitive with temperature. The removal efficiencies for ammonium and phosphorus were 65% and 76% in NM-VFCW, which were 61% and 31% in gravel VFCW. The much higher removal efficiency for phosphorus was mainly attributed to the precipitation of phosphorus which was identified by the SEM and EDS spectrum. Therefore, the manganese ore sand is highlighted as a powerful substrate for simultaneous advanced removal of phosphorus and ammonium in constructed wetland systems. [ABSTRACT FROM AUTHOR]