Understanding the distribution and transportation of phosphorus is vital for the sustainable development of aquatic environmental protection and ecological security. The spatial–temporal distribution of phosphorus fractions in water–sediment phases in river systems and their relationships remain unclear in Southwest China. In this study, the spatial and temporal distribution of phosphorus fractions in water–sediment phases in the Tuojiang River, a primary tributary of the Yangtze River which plays important roles in the economy and ecology of the region, and the relationships among the different phosphorus fractions were analyzed. These fractions were soluble reactive phosphorus (SRP), dissolved organic phosphorus (DOP), and total particulate phosphorus (PP) fractions in water, and exchangeable phosphorus (Ex-P), organic phosphorus (Or-P), phosphorus bound by Fe oxides (Fe-P), authigenic phosphorus (Ca-P), detrital phosphorus (De-P), and refractory phosphorus (Res-P) fractions in sediment. The SPR and Fe-P were the dominant phosphorus fractions in the water and sediment, respectively. The TP content was greater in the lower reaches than in the middle and upper reaches. The average abundances of most phosphorus fractions in water–sediment phases showed significant seasonal variations. The Fe-P, Org-P, and TP in sediments were released to the water interface, resulting in the increase of phosphorus in the overlying water. Redundancy analysis (RDA) indicated that the physicochemical properties of water and sediment have a certain influence on the spatial–temporal distribution of the phosphorus fractions. Principal component analysis (PCA) revealed that the main phosphorus source was anthropogenic activities. These results provide primary data regarding phosphorus fractions and contribute to understanding phosphorus cycling and controlling phosphorus pollution in the Tuojiang River.

The Chinese government has pledged to peak carbon emissions by 2030 and achieve carbon neutrality by 2060. Industrial parks are the key to achieving the carbon peak and neutrality in industrial sectors. Establishing the CO₂ emissions inventory is the first step to achieve the carbon peak in industrial parks. In this study, a comprehensive CO₂ emissions inventory was established for industrial parks, including three parts: energy consumption, industrial process, and waste disposal. We considered scope 1, 2, and 3 emissions and established an uncertainty analysis framework. Accordingly, scope 1 covered the emissions within the park boundary, scope 2 emissions covered those resulting from electricity and heat usage inside the boundary, and scope 3 included those indirect emissions beyond the boundary. The Maanshan Economic and Technological Development Area (MDA), a typical booming national eco-industrial park of China, was chosen for this case study. The results showed that the MDA CO₂ emissions increased yearly, from 376,836.57 tons in 2016 to 772,170.93 tons in 2021. From the industrial structure perspective, heavy industry contributed the highest emissions. By dividing the emissions into scope 1, 2, and 3, scope 2 could be identified as the largest emissions source. In addition, we conducted inventory uncertainty analyses incorporated by activity levels, emissions factors, and unspecific factors. Overall, these results may promote the establishment of greenhouse gas accounting standards for Chinese industrial parks.

Arsenic sulfide residue (ASR) is a solid waste that harms the environment, especially its inherent difficulty in handling sulfur (S). Here, a stabilization pathway based on fly ash (FA) is proposed by directional control and design of curing material proportion and conditions. The leaching behavior and the leaching suppression mechanism of ASR were studied systematically. The results demonstrate that FA-based cement materials effectively stabilize ASR. The leaching concentration of arsenic (As) decreased dramatically from 500 mg/L to 0.4 mg/L after 14 days of optimized curing, achieving a 99 % reduction in leaching toxicity. Response surface methodology (RSM) was employed to analyze the interactive effects of dual factors on solidification, and it was found that CaO, cement content, and liquid/solid (L/S) had strong interaction between the three factors, and L/S played a leading role. During the solidification process of FA-based materials, the initial network and scattered granular loose structure gradually changed to the network/fibrous and acicular dense structure. Moreover, the content of As (V) increased from 49.3 % (3 d) to 79.1 % (14 d), and the structure of metal As in ASR changed from S-As to S-Ca. The stabilization mechanism of arsenic involves four key path ways: calcium silicate hydrate (C-S-H) adsorption, calcium aluminosilicate hydrate (C-A-S-H) precipitation, ettringite incorporation, and physical encapsulation. Therefore, this study provides a stabilization pathway for the harmless treatment of hazardous material by treating it with waste.

The global consensus on sustainable development hinges on the coordinated advancement of economic, social, and environmental dimensions, with high-quality development serving as China’s pivotal pathway for practical implementation. As the primary implementers, cities are confronted with the dual challenge of defining the level of high-quality development and mapping out clear actionable pathways. Therefore, unraveling the driving mechanisms of high-quality urban development is significant. This study constructed a high-quality development evaluation index system, employing a sustainable development index to measure Lianyungang City’s development level from 2008 to 2023. The interrelationships among driving factors were revealed through the coupling coordination degree model, entropy weight method, and Pearson correlation coefficient. The study indicated that innovation stood out as the primary contributor, with contribution rising from 0.09 (2008–2017) to 0.10 (2017–2023). High-tech enterprises and valid invention patents were core drivers of the innovation index’s rise, with weights of 30.35% and 28.92%. Innovation investment promoted the transformation of cities toward technology-intensive development models while effectively supporting Sustainable Development Goals such as industrial upgrading, environmental improvement, and livelihood enhancement. Overall, advancing high-quality urban development required focusing on innovation-driven strategies while catalyzing other areas of development to achieve Sustainable Development Goals.