ObjectiveAgainst the backdrop of rising global trade protectionism, it is of strategic importance to actively assess the export performance of China’s light industry and reshape its international competitive edge, thereby advancing the nation’s manufacturing power strategy. MethodsAfter theoretically examining the mechanism by which industrial chain integration enhances the global competitiveness of China’s light industry, an empirical exploration was conducted by using the trade databases from the United Nations Conference on Trade and Development. ResultsThe findings indicate that China’s light industry exports have long been dominated by medium- and low-technology-density products, while facing dual pressures from the technological suppression by developed countries and cost substitution from emerging economies. As a result, the industry’s international competitive advantage has been gradually weakened. Analysis of industrial chain integration suggests that China’s light industry urgently needs to achieve critical breakthroughs in strategic pivots, such as collaboration capability, development resilience, and value realization.ConclusionsThis paper proposes specific pathways, including the coordinated development of "resource resilience and endogenous intelligent manufacturing", the integration of "standard leadership, channel control, and digital dominance" and the convergence of "operational innovation, value realization, and ecosystem empowerment." These approaches aim to facilitate the strategic transition of China’s light industry from a "technology follower" to a "rule setter" and "value leader", providing valuable insights for the high-quality global expansion of Chinese light industrial manufacturing.
ObjectiveTo address the limited expressiveness of traditional leather decorative techniques and the insufficient application of the cyanotype process on leather, this study investigates the feasibility of applying the cyanotype process to sheep leather and expands its application methods in the design of women’s sheep leather bags, thereby broadening the application scope of the cyanotype process and providing a new technical approach for the visual expression of leather materials in bag design.MethodsResponse surface methodology (RSM) was employed to design the process optimization experiments. Following single-factor experiments, chrome-tanned sheep leather was used as the experimental material. With exposure time, photosensitizer dosage, photosensitizer (ammonium ferric citrate) concentration, and washing time as independent variables, and ΔE*Blue (total color difference between the exposed blue area and the original leather) and ΔE*White (total color difference between the masked white area and the original leather) as response values, a four-factor, three-level RSM experiment was designed using the Box-Behnken module in Design-Expert 13.0 software. A quadratic regression equation model was constructed to investigate the optimal process conditions for cyanotype on sheep leather, aiming to maximize ΔE*Blue and minimize ΔE*White. Subsequently, the cyanotype sheep leather prepared under the optimal conditions was tested for color fastness to rubbing and physical-mechanical properties. At the design practice level, a design method for women’s sheep leather bags based on the cyanotype process was proposed, which specifically includes two parts: the design and production of cyanotype sheep leather and its application in women’s bags.Results(1) The optimal process parameters determined by model optimization were: exposure time of 27 min, photosensitizer dosage of 1 mL, photosensitizer concentration of 0.123 mol/L, and washing time of 16 min. Under these conditions, the theoretical values of ΔE*Blue and ΔE*White for cyanotype sheep leather could reach 45.77 and 4.11, respectively. Validation experiments yielded an average ΔE*Blue of 43.69 (relative error 4.54%) and an average ΔE*White of 4.05 (relative error 1.17%), resulting in clear pattern imaging. Performance tests showed that dry rubbing color fastness reached level 4-5, and wet rubbing color fastness reached level 3-4, meeting the requirements of the QB/T 5087-2017 standard for "Leather for Cases and Bags". The reduction rates of tensile strength (2.84 MPa), elongation at break (41.30%), and softness (5.69 Ri/mm) compared to the original leather were all within 15%, indicating no significant negative impact on the physical properties of the leather. (2) A women’s sheep leather bag featuring blue-and-white porcelain elements was designed, and the design extension of cyanotype sheep leather was achieved through pattern application and multiple decorative techniques.ConclusionsThe cyanotype process under the optimal parameters can produce stable and clear blue–white patterns on the sheep leather surface, with good color fastness and physical properties, and can be used for women’s sheep leather bags. In the future, further exploration can be conducted on the application effect of this process on other types of leather or sheep leather tanned by different methods, as well as its color stability under complex temperature and humidity conditions, and the applicability of other patterns in this cyanotype leather bag design.
ObjectiveDeliming is a key operation connecting liming and bating in leather manufacture. However, ammonium salts, which are widely used as industrial deliming agents, markedly increase the concentration of ammonia nitrogen in wastewater and release ammonia gas, thereby causing environmental burdens. Composite amino acids prepared from keratinous wastes are regarded as a potential alternative to ammonium salts. However, after acid hydrolysis of keratin, large amounts of precipitates are formed during neutralization and usually removed as waste, which results in insufficient resource utilization. In this study, waste wool was used as the raw material, and its whole hydrolysate was directly utilized as a deliming agent (WKH). This strategy aims to reduce ammonia nitrogen pollution at the source while achieving resource utilization of waste biomass. MethodsThe effects of sulfuric acid concentration and hydrolysis temperature on the degree of wool hydrolysis were investigated via single-factor experiments, with hydrolysis rate serving as the evaluation index. The hydrolysate was neutralized with sodium hydroxide to pH 1 to 14, and the neutralization endpoint was determined according to the precipitation characteristics. WKH powder, containing both the supernatant and precipitates formed in neutralization, was prepared under the optimal hydrolysis and neutralization conditions. Its total ash, crude protein, fat content, and amino acid composition were analyzed. Limed cattle hide was employed to compare the deliming performances of 3% ammonium sulfate and different dosages of WKH (4%-8%). During deliming, the pH variation, penetration time at different hide regions, and calcium removal rate were characterized. The delimed hides were processed into crust leather through subsequent procedures, and their softness and mechanical strength were determined. The concentrations of ammonia nitrogen, total organic carbon, and total nitrogen in the deliming float, as well as the release of NH3 and H2S, were measured to assess environmental impact. ResultsThe hydrolysis rate of wool increased significantly with elevated sulfuric acid concentration and hydrolysis temperature. Balancing hydrolysis efficiency and neutralization costs, the optimal hydrolysis conditions were identified as follows: sulfuric acid concentration of 3 mol/L, temperature of 110 ℃, hydrolysis duration of 6 h, and solid-to-liquid ratio of 1∶4. The hydrolysis rate reached approximately 85% under such conditions. During neutralization, the hydrolysate remained homogeneous at pH ≤ 1; precipitation occurred when the pH increased to 2; the amount of precipitate reached its maximum at pH 3-5; and the precipitate gradually redissolved when the pH was further adjusted to the alkaline range. This phenomenon indicated that the precipitate originated from reversible aggregation of amino acids and small peptides near their isoelectric points, which could dissolve in the alkaline environment of pH 12-13 at the initial stage of deliming. Therefore, removal of the precipitate was unnecessary. Accordingly, pH 3 was chosen as the neutralization endpoint. The WKH prepared under the optimal hydrolysis and neutralization conditions contained 59.6% total ash, 32.5% crude protein, and 7.9% fat. Seventeen amino acids were detected, with a total content of 30.8%. In terms of deliming efficiency, the float pH of the 7% WKH group reached 8.6 after deliming for 10 min, which was comparable to that of the 3% ammonium sulfate group. The pH remained stable at 8-9 throughout the deliming process, demonstrating that WKH exhibited a good buffering capacity. In the penetration test, WKH completely penetrated the back and belly regions within 30 min, while complete deliming of the butt and neck regions required 30-50 min. This observation indicated that WKH penetrated slightly more slowly than ammonium sulfate (which achieved complete deliming in all regions within 30 min) but was superior to most reported organic acid deliming agents. In terms of calcium elimination, the calcium removal rates of the 5%-8% WKH groups were all higher than those of the 3% ammonium sulfate group. This was attributed to the ability of carboxyl groups in amino acids to form soluble calcium salts with calcium ions that were fixed on the limed hide. The crust leather prepared by WKH deliming showed softness and mechanical strength comparable to those of the ammonium sulfate group, demonstrating that WKH had no adverse effect on the physical properties of the crust leather. Compared with ammonium sulfate deliming, 7% WKH deliming reduced the concentration of ammonia nitrogen in the wastewater from 4267.2 mg/L to 199.3 mg/L, corresponding to a removal efficiency of 95.3%. The carbon-to-nitrogen ratio increased from 0.2 to 2.0, which was beneficial for improving the biodegradability of wastewater. With respect to the release of odorous gases, the NH3 release from WKH deliming was 4.5 mg/m3, representing an 80.3% reduction compared with ammonium sulfate deliming, which released 22.9 mg/m3. The H2S release was only 37.9 μg/m3, much lower than that of the formic acid-treated group. ConclusionIn summary, a deliming agent was prepared via the full-component utilization of waste wool, which effectively avoids resource loss associated with the disposal of neutralization precipitates generated during conventional keratin hydrolysis. The deliming performance of WKH was comparable to that of ammonium sulfate, while it achieved a remarkable reduction in the sources of ammonia nitrogen and odorous gases. This work provides a feasible technical route for cleaner leather manufacturing and the resource utilization of waste.
BackgroundVarious pollutants present in industrial wastewater, such as heavy metal ions, radionuclides and organic compounds, are high-toxic and refractory, posing a severe threat to ecological environmental safety and human health. Adsorption method is one of the best technologies for the purification of wastewater due to its advantages of simple operation and controllable cost. Lignin shows innate advantages as an adsorbent for the treatment of industrial wastewater, in terms of unique aromatic skeleton, three-dimensional network structure, and diverse sources. Analysis/ProgressIn this paper, the sources, structural characteristics, and reactivity of lignin were elaborated to facilitate the preparation of lignin-based adsorbents. Meanwhile, the core five modification methods, which convert lignin into functional adsorbents, were also analyzed. In detail, activation and carbonization focus on optimizing pore structure and increasing specific surface area, aiming to enhance adsorption capacity. Modification via lignin nanoparticle preparation centers on improving dispersibility and surface activity through nanonization, with an emphasis on accelerating adsorption rate. Composite modification with magnetic materials is based on synergistic adsorption and magnetic separation, focusing on enhancing practical application convenience. Grafting modification targets precise introduction of functional groups, emphasizing improved adsorption selectivity. In practical applications, either a single modification method or a combined modification strategy (such as activation-grafting combination or magnetic-carbonization combination) can be selected according to the type of target pollutants, cost budget, and application scenario. For heavy metal ions, as one of the key concerns in wastewater, which exhibit distinct charge states in aqueous solution, targeted chemical and physical modification of lignin is effective to enhance the adsorption performance. For instance, grafting amino groups onto lignin can achieve the effective chelation of anionic metals (Cr2O72− and AsO43−), while immobilizing carboxyl groups onto the lignin surface enables the adsorption of cationic metals (Zn2+ and Pb2+) via forming stable carboxylate complexes. For the organic pollutants, introducing hydrophobic groups (such as alkyl groups and benzene rings) and porous structure onto the lignin surface can realize efficient adsorption of organic contaminants via multiple interaction mechanisms. In particular, the composite modification of lignin with advanced materials, such as reduced graphene oxide and carbon nanotubes, can construct a synergistic system of "porous structure-strong π-π interaction", thereby significantly improving the adsorption capacity of lignin-based materials for refractory organic pollutants. For other categories of contaminants, metal ion doping and amination are recognized as effective approaches for remarkably enhancing the adsorption performance of lignin-based materials. The radionuclides, such as uranium (U(Ⅵ)), cesium (Cs+), and strontium (Sr2+), are characterized by long half-lives, high toxicity, and high mobility. They can be effectively disposed by lignin-based adsorbents due to the strong functional modifiability and good selectivity, which have become a potential alternative to traditional expensive ion-exchange resins. Conclusion/ProspectAs a novel, low-carbon, green, and low-cost adsorbent material, lignin-based adsorbents show broad application prospects in wastewater treatment. Through techniques such as activation modification, nano crystallization modification, magnetic composite modification, and graft copolymerization modification, the structure and surface properties of lignin can be effectively regulated, thereby significantly improving its adsorption performance and enabling the efficient adsorptive removal of various pollutants from wastewater, including heavy metal ions, organic pollutants, nitrogen and phosphorus compounds, radionuclides, and others. Although current lignin-based adsorbents still face challenges such as unstable raw material quality, difficulties in large-scale preparation, and unsatisfactory regeneration performance, with the continuous optimization and innovation of modification technologies, the precise regulation of adsorbent structures, and the development of green and efficient preparation and regeneration technologies, lignin-based adsorbents are expected to achieve large-scale industrial application. This will provide important support for solving water resource pollution problems and promoting the high-value utilization of renewable resources.
ObjectiveIn response to the growing concern over the potential health and environmental risks posed by dichlorophen residues in leather and textile products, this study established an analytical method based on ultrasonic extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was developed to enable sensitive and reliable determination of dichlorophen in complex matrices. Furthermore, the applicability of this method for product quality safety risk monitoring was evaluated through interlaboratory validation and the analysis of real-world samples, aiming to provide technical support for regulatory compliance and industrial upgrading. MethodsThe optimal analytical conditions were determined through the systematic optimization of sample pretreatment conditions (extraction method, solvent type and volume, extraction temperature and time) and instrumental parameters (mobile phase composition and flow rate, mass spectrometric ionization mode and monitored ion pairs). Specifically, the sample was accurately weighed, followed the addition of 10 mL of methanol for thorough saturation, and the ultrasonic extraction was then performed in a 60 ℃ water bath for 50 min. After cooling to room temperature, the extract was purified through a 0.22 μm organic filter membrane. Chromatographic separation was carried out on a C18 column with isocratic elution using acetonitrile-water as the mobile phase. Mass spectrometric detection was performed in electrospray negative ion mode (ESI−) under multiple reaction monitoring (MRM) mode, and quantification was achieved by the external standard method. The selection of ultrasonic extraction over conventional methods was based on its higher extraction efficiency and lower solvent consumption. The optimization process involved univariate experiments to identify the most influential factors, ensuring robustness and reproducibility. ResultsUnder the optimized conditions, dichlorophen showed a good linear relationship in the concentration range of 5-1000 μg/L, with a correlation coefficient (R2) of 0.999 9. The wide linear range indicates the method’s suitability for both trace-level and relatively high-concentration analyses. The limit of detection (LOD) was calculated as 0.05 mg/kg, based on a signal-to-noise ratio of 3 times the background. This low LOD ensures the method’s capability to detect dichlorophen residues at levels far below the strictest regulatory limits, such as those specified in OEKO-TEX Standard 100. Recovery tests were performed using blank matrices of leather, artificial leather, and textiles spiked at low, medium, and high concentration levels. The average recoveries of dichlorophen ranged from 92.15% to 111.62%, indicating satisfactory accuracy of the method. The relative standard deviations (RSDs) obtained from eight parallel measurements were between 2.83% and 7.61%, demonstrating good precision. The method was further validated through interlaboratory comparison, and the results exhibited good repeatability across different laboratories, confirming its robustness and transferability.ConclusionsThis method features simple pretreatment steps, low consumption of organic solvents, high sensitivity, and good reproducibility. It can effectively eliminate the interference from complex matrices, meeting the requirements for rapid qualitative and quantitative determination of dichlorophen residues in actual samples. The use of methanol as the sole extraction solvent minimizes environmental impact and operational hazards. The method is particularly suitable for routine screening of large batches of leather and textile products, where time efficiency and accuracy are critical. It also provides reliable technical support for quality and safety control, risk early warning, and compliance testing of leather and textile products, demonstrating good potential for wide application and promotion.
