With the advancement of China’s agricultural modernization and scientific and technological progress, there has been a substantial increase in corn production, resulting in significant agricultural waste of materials such as corncobs. Conventional incineration methods fail to efficiently utilize the recyclable resources present in corncobs. In this investigation, corncob biochar film (CBC) was synthesized through the pyrolysis of corncob. Single-factor and orthogonal experiments were used to determine the conditions needed to prepare biochar film with the best Cr(VI) adsorption effect. The experiments showed that at a heating rate of 5 °C/min, pyrolysis temperature of 500 °C and pyrolysis time of 120 min, the Cr(VI) removal rate of prepared biochar film reached 73.55% and the adsorption capacity was 18.39 mg/g. Meanwhile, the factors affecting the removal of Cr(VI), including pH value, initial concentration of Cr(VI) solution, dosage of adsorbent, adsorption kinetics and isothermal adsorption, were analyzed in detail. The structures of CBC before and after Cr(VI) adsorption were analyzed by SEM, FTIR, XRD, XPS, and BET. These findings demonstrate the efficacy of corncob biochar film in Cr(VI) removal.

Microbial fuel cells (MFCs) generate electricity through the microbial oxidation of organic waste. However, the inherent electrochemical performance of carbon felt (CF) electrodes is relatively poor and requires enhancement. In this study, nickel oxide (NiO) was successfully loaded onto CF to improve its electrode performance, thereby enhancing the electricity generation capacity of MFCs during the degradation of treated wastewater. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy diffusion spectrometer (EDS) analyses confirmed the successful deposition of NiO on the CF surface. The modification enhanced both the conductivity and capacitance of the electrode and increased the number of microbial attachment sites on the carbon fiber filaments. The prepared CF–NiO electrode was employed as the anode in an MFC, and its electrochemical and energy storage performance were evaluated. The maximum power density of the MFC with the CF–NiO anode reached 0.22 W/m², compared to 0.08 W/m² for the unmodified CF anode. Under the C1000-D1000 condition, the charge storage capacity and total charge output of the CF–NiO anode were 1290.03 C/m² and 14,150.03 C/m², respectively, which are significantly higher than the 452.9 C/m² and 6742.67 C/m² observed for the CF anode. These results indicate notable improvements in both power generation and energy storage performance. High-throughput gene sequencing of the anodic biofilm following MFC acclimation revealed that the CF–NiO anode surface hosted a higher proportion of electroactive bacteria. This suggests that the NiO modification enhances the biodegradation of organic matter and improves electricity generation efficiency.

This study addresses the challenge of chitosan (CS) being difficult to dissolve in water due to its highly ordered crystalline structure. Chitosan is modified with chloroacetic acid to reduce its crystallinity and enhance its water solubility. Through single-factor experiments, the optimal conditions for preparing carboxymethyl chitosan film (CMCS) were determined: under conditions of 50 °C, a cellulose substrate (CS) concentration of 18.75 g/L, a NaOH concentration of 112.5 g/L, and a chloroacetic acid concentration of 18.75 g/L, the reaction proceeded for 5 h. Under these conditions, the resulting carboxymethyl chitosan film exhibited the best flocculation effect, forming chitosan films in water that had flocculation activity toward mung bean starch protein wastewater. The successful introduction of carboxyl groups at the N and O positions of the chitosan molecular chain, which reduced the crystallinity of chitosan and enhanced its water solubility, was confirmed through analysis using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The prepared carboxymethyl chitosan film (CMCS) was applied in the flocculation recovery of protein. Through single-factor and response surface experiments, the optimal process conditions for flocculating and recovering protein with CMCS were determined: a CMCS dosage of 1.1 g/L, a reaction time of 39.6 min, a reaction temperature of 42.7 °C, and a pH of 5.2. Under these conditions, the protein recovery rate reached 56.97%. The composition and amino acid profile of the flocculated product were analyzed, revealing that the mung bean protein flocculated product contained 62.33% crude protein. The total essential amino acids (EAAs) accounted for 52.91%, non-essential amino acids (NEAAs) for 47.09%, hydrophobic amino acids for 39.56%, and hydrophilic amino acids for 12.67%. The ratio of aromatic to branched-chain amino acids was 0.31, and the ratio of basic to acidic amino acids was 1.68. These findings indicate that the recovered product has high surface activity and good protein stability, foaming ability, and emulsifying properties.

In this study, pomelo peel waste was utilized as the raw material to extract flavonoids, which were subsequently microencapsulated with β-cyclodextrin (β-CD) and incorporated into a corn starch/konjac glucomannan composite film matrix, aiming to develop biodegradable candidate films containing an antioxidant extract for potential food packaging applications. The extraction conditions for pomelo peel flavonoids (PF) were optimized via response surface methodology, yielding the optimal parameters as follows: extraction time of 123.88 min, temperature of 69.07 °C, etc., under which the total PF extraction rate reached 5.958%. At high concentrations, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacities of the obtained PF did not differ significantly from those of ascorbic acid. The fabricated PF-loaded β-cyclodextrin microcapsules (PF-CD-MCs) achieved an encapsulation efficiency of 71.24 ± 0.21%, the morphological and spectroscopic results suggested the successful formation of the inclusion complex and were incorporated into the composite films at varying addition levels ranging from 0% to 40% (w/w). The results demonstrated that the loading content of PF-CD-MCs played a critical regulatory role in the microstructure and macroscopic properties of the films. At 10% loading, the water vapor permeability (WVP) reached its minimum, whereas 20% loading provided the best overall compromise: the microcapsules remained uniformly dispersed without recrystallization, the film retained acceptable barrier and mechanical performance, and the active loading was higher than that at 10%. At 30%–40%, aggregation and recrystallization caused structural defects and marked deterioration in WVP, mechanical strength, and water resistance. Therefore, 20% is recommended as a comprehensive loading level rather than a single-property optimum. This study provides important theoretical foundations and technical references for the high-value utilization of pomelo peel waste and the rational design of biodegradable active packaging materials.

Microbial Fuel Cell (MFC) is a novel bioelectrochemical system that catalyzes the oxidation of chemical energy in organic waste and converts it directly into electrical energy through the attachment and growth of electroactive microorganisms on the electrode surface. This technology realizes the synergistic effect of waste treatment and renewable energy production. A CF-NiO-PANI capacitor composite anode was prepared by loading polyaniline on a CF-NiO electrode to improve the capacitance of a CF electrode. The electrochemical characteristics of the composite anode were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the electrode materials were analyzed comprehensively by scanning electron microscopy (SEM), energy diffusion spectrometer (EDS), and Fourier transform infrared spectroscopy (FTIR). MFC system based on CF-NiO-PANI composite anode showed excellent energy conversion efficiency in potato starch wastewater treatment, and its maximum power density increased to 0.4 W/m³, which was 300% higher than that of the traditional CF anode. In the standard charge–discharge test (C1000/D1000), the charge storage capacity of the composite anode reached 2607.06 C/m², which was higher than that of the CF anode (348.77 C/m²). Microbial community analysis revealed that the CF-NiO-PANI anode surface formed a highly efficient electroactive biofilm dominated by electrogenic bacteria (accounting for 47.01%), confirming its excellent electron transfer ability. The development of this innovative capacitance-catalytic dual-function anode material provides a new technical path for the synergistic optimization of wastewater treatment and energy recovery in MFC systems.

In this study, a dual-crosslinked Ca²⁺-SA/LMCP hydrogel network with both elasticity and toughness was constructed via Ca²⁺ crosslinking of low-methoxyl citrus pectin (LMCP) and sodium alginate (SA). Cellulose Nanofiber (CNF) was then incorporated as a physical reinforcing phase, interacting with the Ca²⁺-SA/LMCP network through hydrogen bonding and physical entanglement to further enhance the physical framework strength. Finally, rutin (RTN) was loaded into this system as an antibacterial agent, and the system was freeze-dried to fabricate antibacterial aerogel preservation sheets with an ionically crosslinked and physically entangled dual-network structure composed of Ca²⁺-SA, LMCP, and CNF. The effects of RTN concentration on the porous structure and mechanical properties of the composite aerogels were investigated. The surface micromorphology, functional groups, thermal behavior, and crystalline structure of the LMCP/SA/CNF/RTN composite aerogels were characterized in detail by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and X-Ray Diffraction (XRD). Notably, a well-developed porous structure was observed in the composite aerogel when the Ca²⁺ concentration was 15 mmol/L, pH was 4, the LMCP/SA mass ratio was 1:1, and the CNF concentration was 15 mg/mL. The antibacterial activity, loading capacity, and mechanical properties of the aerogels were further verified through mechanical tests, swelling tests, and antibacterial assays. The experimental results showed that the maximum compressive modulus of the LMCP/SA/CNF aerogel was 6.57 MPa, and the compressive stress was 1.313 MPa. The swelling ratio of the LMCP/SA/CNF/RTN composite aerogel in PBS reached 2246%. Antibacterial assays revealed that composite aerogels with different RTN concentrations all exhibited inhibitory effects against Staphylococcus aureus; notably, the inhibition zone diameter of the aerogel containing 0.5 g RTN reached 9.8 mm. In summary, the development of this innovative antibacterial aerogel material demonstrates its application potential as a packaging cushioning material, providing new technical insights for this field.