Yuanyan Zhang

As a major economic corridor and ecological barrier in China, the Yangtze River Economic Belt (YREB) has experienced substantial land-use changes that have significantly influenced regional landscape patterns and sustainability. However, the long-term evolution of landscape patterns and their driving mechanisms remain insufficiently understood, particularly considering the spatial heterogeneity among different regions. Based on land-use datasets from 1993 to 2023, this study integrated land-use transfer analysis, grid-based landscape metrics, and the Geodetector model to examine the spatiotemporal evolution of landscape patterns and their driving factors across the YREB. The results showed that cultivated land decreased from 34.63% to 32.78%, forest land increased from 51.51% to 52.36%, and built-up land expanded from 1.36% to 3.61%. Rapid urban expansion was the primary driver of landscape pattern change, leading to increased fragmentation and landscape complexity. Significant regional differences were observed, with relatively stable landscape structures in the upper reaches, transitional changes in the middle reaches, and intensive landscape reorganization in the lower reaches. Both natural and socioeconomic factors influenced landscape evolution, while their interactions generally exerted stronger explanatory power than individual factors. These findings provide valuable support for ecological conservation, land-use optimization, and territorial spatial planning in the YREB.

Iron–carbon micro-electrolysis and combined processes were used to treat simulated dyeing wastewater containing direct Big Red 4BE dye (concentration of 1500 mg/L, chromaticity of 80,000 times, and salt content of 20 g/L). Through single-factor experiments, the optimal reaction conditions were determined as follows: reaction time of 110 min, initial pH of 5, and iron and carbon mass ratio of 1:2. Under the optimal conditions, the concentration was reduced to 14.51 mg/L, the chromaticity was reduced to 3000 times, and the decolorization rate reached 99.03%. In order to further decrease the wastewater chromaticity, coagulation and Fenton oxidation were respectively employed for in-depth treatment after iron–carbon micro-electrolysis. The total decolorization rate of the dye wastewater exceeded 99.7%, with the treated effluent meeting the specified chromaticity discharge standard (80-fold). The integrated processes of iron–carbon micro-electrolysis combined with either coagulation sedimentation or Fenton oxidation demonstrated superior performance in treating direct Big Red 4BE dye wastewater.

IIron-carbon micro-electrolysis and combined process were used to treat printing and dyeing wastewater, which was formulated with direct Big Red 4BE dye (concentration of 1500mg/L, chromaticity of 80,000 times, and salt content of 20g/L). The optimal conditions were determined by one-factor experiments, with a reaction time of 110 min, an initial pH of 5, and an iron and carbon mass ratio of 1:2. Under the optimal conditions, the concentration was reduced to 14.51mg/L, the chromaticity was reduced to 3,000 times, and the decolourization rate reached 99.03%. In order to further reduce the chromaticity of the wastewater, coagulation and Fenton oxidation were used to treat the wastewater in depth after the iron-carbon micro-electrolysis, respectively. The total decolorization rate of the dye wastewater reached more than 99.7%, and the treated wastewater met the emission standard of 80 times the chromaticity in the "Discharge Standard of Water Pollutants for Textile Dyeing and Finishing Industry" (GB4287-2012). The combination of iron-carbon micro-electrolysis and coagulation sedimentation or Fenton oxidation had a good effect on the treatment of direct Big Red 4BE dye wastewater.