The aim of this study was to investigate the effects of the heat treatment time and initial moisture content of bamboo on the corresponding chemical composition, crystallinity, and mechanical properties after saturated steam heat treatment at 180 °C. The mechanism of saturated steam heat treatment of bamboo was revealed on the micro-level, providing a theoretical basis for the regulation of bamboo properties and the optimization of heat treatment process parameters. XRD patterns of the treated bamboo slices were basically the same. With the increase in the initial moisture content of bamboo, the crystallinity of bamboo increased first and then decreased after treatment. Due to the saturated steam heat treatment, the content of cellulose and lignin in bamboo slices increased while the content of hemicellulose decreased, but the content of cellulose in bamboo with a 40% initial moisture content increased first and then decreased. The shear strength of treated bamboo changed little within 10 min after saturated steam heat treatment, and then decreased rapidly. During the first 20 min with saturated steam heat treatment, the compressive strength, flexural strength, and flexural modulus of elasticity of the treated bamboo increased, and then decreased.
In recent decades, dye wastewaters produced by dye-manufacturing and dye-consuming industries have become a growing water pollution problem. Herein, a novel phenolic foam-derived magnetic carbon foam is synthesized by in-situ pyrolysis of iron acetylacetonate (Fe(acac)3) containing phenolic resin and its corresponding application as an adsorbent for the removal of Rhodamine B from effluent is investigated. The characterization of the as-prepared adsorbent is carried out by SEM, EDS, XRD, XPS, VSM, FT-IR, Raman, and BET. The magnetic carbon foam is observed to consist of a CFe15.1/C matrix modified with α-Fe/Fe3C/Fe2O3 composites, possessing a 3D porous architecture formed by inter-connected cells with diameters of 50–200 μm and narrow ligaments with thicknesses of ~20 μm. Experimental tests demonstrate that the equilibrium of adsorption behavior of Rhodamine B onto the obtained adsorbent can be reached within 40 min and the corresponding maximum adsorption capacity is 258.03 mg/g. The effects of contact time and adsorbent dosage on the adsorption performance are investigated. Besides, four models are introduced to fit the experimental data to evaluate the adsorption kinetics. The overall rate constant is determined by the chemisorption process, according to the pseudo-second order adsorption kinetics mechanism. Besides, the pH effect on RhB adsorption onto magnetic carbon foam is investigated, with the pH values varying from 3 to 10. The above results prove the application prospect of magnetic carbon foam prepared in this work in dye wastewater treatment.
With the scarcity of wood resources and calls for “substituting bamboo for wood” and “substituting bamboo for plastic”, bamboo has gained greater popularity for its abundant reserves and outstanding mechanical properties. However, Mildew is a common problem for bamboo, which can significantly reduce the quality and service lives of bamboo products. In this work, a safe, eco-friendly, controllable and efficient method of gamma-ray irradiation was used to modify bamboo. The irradiation dose, moisture content (MC), and irradiation dose rate were adopted as factors of an orthogonal experiment. The results showed that the bamboo strips reached their best mechanical properties under the condition of irradiation at 150 KGy doses, moisture content of 40%, and irradiation dose rate of 44 KGy/H. In addition, the change in the chemical composition of bamboo and mildew resistance was also explored in this paper. The major chemical components (cellulose, hemicellulose and lignin), as well as starch, were degraded, and the bamboo strips exhibited excellent mildew resistance after gamma-ray irradiation.