RESUMEN
Thermal pretreatment (TP) was an effective method to improve the anaerobic digestion of waste-activated sludge. In order to balance the energy consumption of sludge TP integrated with anaerobic digestion, food waste was introduced as a co-substrate to achieve an energy self-sustainable sludge treatment system. An anaerobic biodegradability test was performed using thermal pretreated sludge and food waste in order to clarify the kinetics and mechanism of co-digestion, especially the synergetic effect on specific methane yield. The prominent synergetic effect was an initial acceleration of cumulative methane production by 20.7-23.8% observed during the first 15 days. The modified Gompertz model presented a better agreement of the experimental results, and it was a suitable tool for methane production prediction of mono- and co-digestion. The energy assessment showed that co-digestion with food waste was a sustainable solution. When the moisture content of the TP sludge was 80-90%, the energy compensation required was about 0.04-0.22 t VSFoodwaste/t VSSludge, which could maintain the integration of neutral or even positive energy between TP and anaerobic digestion.
RESUMEN
In this paper, nano/microfibrils were applied to enhance the mechanical and hydrophobic properties of the sugarcane bagasse fiber films. The successful preparation of nano/microfibrils was confirmed by scanning electron microscope (SEM), X-ray diffraction (XRD), fiber length analyzer (FLA), and ion chromatography (IC). The transparency, morphology, mechanical and hydrophobic properties of the cellulose films were evaluated. The results show that the nanoparticle was formed by the hemicellulose diffusing on the surface of the cellulose and agglomerating in the film-forming process at 40 °C. The elastic modulus of the cellulose film was as high as 4140.60 MPa, and the water contact angle was increased to 113°. The micro/nanostructures were formed due to hemicellulose adsorption on nano/microfilament surfaces. The hydrophobicity of the films was improved. The directional crystallization of nano/microfibrous molecules was found. Cellulose films with a high elastic modulus and high elasticity were obtained. It provides theoretical support for the preparation of high-performance cellulose film.
RESUMEN
Nanofibrillated cellulose and microfibrillated cellulose are potential raw materials separated from plant fibers with a high aspect ratio and excellent mechanical properties, which can be applied in various fields (packaging, medicine, etc.). They have unique advantages in the preparation of aerogels and foams, and have attracted widespread attention in recent years. Cellulose-based porous materials have good biodegradability and biocompatibility, while high porosity and high specific surface area endow them with strong mechanical properties and liquid retention performance, which can be used in wall construction, sewage treatment and other fields. At present, the preparation method of this material has been widely reported, however, due to various process problems, the actual production has not been realized. In this paper, we summarize the existing technical problems and main solutions; in the meantime, two stable systems and several drying processes are described, and the application potential of cellulose-based porous materials in the future is described, which provides a reference for subsequent research.