Aerobic composting is an effective method of resource treatment for agricultural and forestry solid waste; however, while wheat straw is usually used as a conditioner and is not the main body as in aerobic composting, wheat straw is abundant in annual production, and fertilization is one of the main ways of resource utilization of wheat straw, how to use wheat straw as the main body of aerobic composting for efficient treatment is, therefore, a meaningful research direction. In this paper, to achieve the efficient and economic resource utilization of wheat straw and livestock manure, aerobic composting was carried out with wheat straw as the main body, and pig manure and cow manure were mixed with wheat straw crops at ratios of 20%, 30%, and 40%, respectively, for barrel suspension composting. The changes in pH, EC, NH₄⁺-N, NO₃⁻-N, TN, TP, organic matter and seed germination index, and shoot length inhibition rate before and after composting were compared between treatment groups using different material ratios in the aerobic composting process. The changes in the physicochemical properties and nutrient elements of compost products were studied. The results show that the co-composting of livestock manure and wheat straw can promote the decomposition of the pile, and the addition of 40% cow manure and 30% pig manure has the best effect in promoting decay. In contrast, the addition of excessive pig manure inhibits the decomposition of the pile. Organic matter degradation in the treatment groups using cow manure was more effective than in those using pig manure, and the best results were obtained with 40% cow manure. The pile was alkaline at the end of each treatment, and the wheat straw compost treated with 40% cow manure had the best nitrogen and phosphorus retention. The wheat straw compost treated with 40% cow manure had the highest integrated degree of decomposition, which promoted the deterioration of the pile and provided a research basis for the use of wheat straw as an efficient resource.

Different types of subsidence lakes formed by underground coal mining are severely polluted by mine-production wastewater, domestic sewage, and agricultural irrigation water. Microbial communities perform a crucial role in biogeochemical cycling processes and responses to natural and anthropogenic disturbances in lake waters. Therefore, it is important to investigate the characteristics of microbial community diversity in subsidence lakes for the utilization of water resources in mining areas. In this study, we collected water samples from open and closed subsidence lakes and explored the bacterial communities based on Illumina amplicon high-throughput sequencing. Results showed that bacterial diversity and community and functional composition in open and closed lakes differed greatly, and the bacterial diversity in open lakes was significantly higher than that in closed lakes (p < 0.001). Canonical correspondence analysis found that pH explained 31.73% and 39.98% of the variation in the bacterial community and functional composition in closed lakes, while NH₄⁺ and COD accounted for 29.73% and 26.02% of the changes in the community and functional composition in open lakes, respectively. Modified stochasticity ratios based on null-model analysis demonstrated that stochastic processes were the main factor affecting bacterial community assembly in both closed (MST = 0.58) and open lakes (MST = 0.63). In the closed-lake network, hgcI_clade was inferred to be a keystone species, while Lactococcus, Acinetobacter, Psychrobacter, and Chryseobacterium were detected as keystone species in the open-lake network. By way of discussion, we provide evidence regarding the bacterial community diversity, structure, co-occurrence patterns, and assembly processes in closed and open subsidence lakes. This study contributes to providing a reference for the utilization of subsidence water resources.

In ecologically fragile arid and semi-arid mining regions, open-pit mining has created extensive spoil dumps characterized by extreme soil moisture and temperature regimes, constituting the primary challenge for vegetation restoration and ecological rehabilitation. To address this challenge, there is an urgent need to explore novel rehabilitation approaches that reconcile energy development with ecological conservation. This study investigated retaining wall on open-pit coal mine spoil dump, utilized an integrated approach of field monitoring and numerical simulation to elucidate the regulatory effects and mechanisms of retaining wall on soil moisture and temperature distribution. The results indicated that the retaining wall significantly improved the water retention and temperature regulation ability on the leeward side. The influence of the retaining wall on the leeward side was concentrated in the range of 1-1.5 m, and the depth of influence was mainly concentrated in the surface layer and 10 cm soil layer. In the surface soil layer, the soil moisture on the leeward side (average 23.93%) increased by 2.66% compared to the windward side (average 21.27%), and the variation range of soil temperature on the leeward side (21.0-26.5 °C) was less than that on the windward side (19.5-25.4 °C). Furthermore, the soil water dissipation rate on the leeward side (linear fit slope: -0.10) was 33.3% lower than that on the windward side (linear fit slope: -0.15). Numerical simulations further elucidated that by altering local airflow patterns, retaining wall facilitated the formation of a windless zone extending over 3 m horizontally on the leeward side under wind speeds of 4 m·s ^-1 , thereby mitigating evaporation and temperature fluctuations. This study elucidates the ecological regulation potential of retaining walls beyond traditional mechanical functions, providing new theoretical support and technical approaches for low-cost ecological restoration of open-pit coal mine waste dumps in arid and semi-arid regions.

A comprehensive analysis of the regional and temporal distribution characteristics of carbon sequestration ecological carrying capacity (ESC), along with their affecting factors, is crucial for attaining the “double carbon” objective. This study analyzes the regional and temporal distribution of ESC in Anhui Province from 2008 to 2022, employing the Moran index and cold hotspot analysis. The principal social, economic, and environmental influencing factors of 16 prefectural-level cities in Anhui Province have been identified using the Random Forest Model (RFM), and the spatial effects of these factors have been examined through the Spatial Durbin Model (SDM). The ESC in Anhui Province revealed that southern Anhui had a bigger capacity than central Anhui, which surpasses northern Anhui. The ESC in Anhui Province from 2008 to 2022 demonstrated an initial increase, followed by a subsequent decline. The ESC in Anhui Province exhibits significant geographic aggregation effects, with no discernible areas of low ESC and a more stable hotspot region throughout the study period. Subsequent study indicates that water network density and population size are the primary determinants of ESC across 5-, 10-, and 15-year intervals, exhibiting notable regional spillover effects. The study’s results offer significant theoretical insights for examining regional ESC and developing low-carbon solutions.