In situ formed CaSO4 on waste dander biochar to inhibit the mineralization of soil organic carbon

In order to reduce CO2 emissions, as well as realize the resource utilization of waste dander (WD) and the goal of international "peak carbon dioxide emissions" and "carbon neutrality", Biochar was prepared with WD via pyrolysis technology, achieving CaSO4 in situ generated on its surface, which could be used to inhibit soil organic carbon (SOC) from mineralizing and enhance soil carbon sequestration ability. The characterization results showed that the unstable carbon (C) structures as well as more conjugated structures were generated on Ca-BC, obtaining an increased C sequestration of Ca-BC to 21.70 %. With the application of Ca-BC, the mineralization rate of SOC was reduced to 0.451 mg CO2/(g·d), and the soil moisture content, pH and TOC content were increased to 45.48 %, 7.96 and 47.19 %. In addition, the bioinformatics analysis and redundancy analysis revealed that the application of Ca-BC promoted bacteria to convert into the stable C-dominant phyla (Firmicutes).

Recent Advances on the Development of Protein-Based Adhesives for Wood Composite Materials-A Review

The industrial market depends intensely on wood-based composites for buildings, furniture, and construction, involving significant developments in wood glues since 80% of wood-based products use adhesives. Although biobased glues have been used for many years, notably proteins, they were replaced by synthetic ones at the beginning of the 20th century, mainly due to their better moisture resistance. Currently, most wood adhesives are based on petroleum-derived products, especially formaldehyde resins commonly used in the particleboard industry due to their high adhesive performance. However, formaldehyde has been subjected to strong regulation, and projections aim for further restrictions within wood-based panels from the European market, due to its harmful emissions. From this perspective, concerns about environmental footprint and the toxicity of these formulations have prompted researchers to re-investigate the utilization of biobased materials to formulate safer alternatives. In this regard, proteins have sparked a new and growing interest in the potential development of industrial adhesives for wood due to their advantages, such as lower toxicity, renewable sourcing, and reduced environmental footprint. This work presents the recent developments in the use of proteins to formulate new wood adhesives. Herein, it includes the historical development of wood adhesives, adhesion mechanism, and the current hotspots and recent progress of potential proteinaceous feedstock resources for adhesive preparation.

Conversion of tannery solid waste to an adsorbent for high-efficiency dye removal from tannery wastewater: A road to circular utilization

The high value-added use of tannery solid waste and elimination of tannery liquid waste in the leather-making industry have attracted widespread attention. In this study, a MgO-doped biochar (MgO/BC) adsorbent was successfully prepared by utilizing tannery solid waste (i.e., non-tanned hide wastes) as the biomass material for dye removal from tannery wastewater. Characterization results indicated that MgO was uniformly embedded into the porous BC structure. The adsorption capacity of acid orange II by MgO/BC reached up to 448.4 mg g^-1, which drastically exceeded the pure BC and other reported adsorbents. The adsorption behavior of acid orange II by MgO/BC matched nicely with Langmuir isotherm and pseudo-second-order kinetic model. This satisfactory adsorption capacity of MgO/BC for acid orange II was mainly due to the large specific surface area and the enhanced electrostatic interaction. According to the BET, zeta potential and XPS analysis, the possible mechanism towards acid orange II removal was attributed to the pore filling, surface complexation, electrostatic attraction and π-π interaction. In addition, MgO/BC showed the efficient removal towards anionic dyes from actual tannery wastewater. This work could provide guidance for the value-added utilization of tannery solid waste and a practical way to remove dyes from tannery wastewater.

Film-forming ability of collagen hydrolysate extracted from leather solid wastes with chitosan

Discharges of huge quantities of leather solid wastes by leather industries and the increased use of synthetic packaging films have raised serious concerns on account of their environmental impacts. The paper focuses on the development and characterization of potential environmentally friendly composite films using collagen hydrolysate (CH) extracted from leather solid wastes and chitosan (C) to assess the feasibility of producing polymeric materials suitable for applications in packaging and wrapping purposes. Solid collagen-based protein hydrolysate was extracted from chromium-tanned leather wastes and analyzed to determine its chemical properties. With the goal of improving the physico-chemical performance of CH, three types of composite films (CH75/C25, CH50/C50, CH25/C75) were prepared with increasing concentrations of C, and some of their physical and functional properties were characterized. The results indicated that the addition of C caused increase (p < 0.05) in the thickness, tensile strength (TS), elasticity modulus (EM), and water vapor permeability (WVP), leading to stronger films as compared with CH film, but significantly (p < 0.05) decreased the elongation at break (EAB) and solubility of films (p < 0.05). The light barrier measurements present low values of transparency at 600 nm of the CH/C films, indicating that the films are very transparent and they have excellent barrier properties against UV light. The structural properties investigated by FTIR and DSC showed total miscibility between both polymers. Scanning electron micrographs revealed that CH/C composite films showed a compact homogeneous structure. These results demonstrate the potential application of CH/C composite films in packaging industry.