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The Huixian Wetland is a natural ecosystem of immense ecological value, providing crucial ecosystem services such as water purification, water regulation, and a habitat for the region's flora and fauna. Its karst peak forest landforms and surrounding environment also possess unique ecological and landscape value. However, with the ongoing socioeconomic development, including the rise of industrial, agricultural, and aquaculture activities in the wetland area, the nutrient composition of the Huixian Wetland has been altered. This paper reviews the current status of nitrogen, phosphorus, heavy metals, emerging pollutants, and biodiversity in various environmental media of the Huixian Wetland. It synthesizes the literature to identify the factors influencing these changes and projects future research directions for the wetland. This work is of significant practical importance, providing scientific foundations for the restoration and protection of the Huixian Wetland. [ABSTRACT FROM AUTHOR]

The Yellow River holds significant developmental and historical importance for China. Over the past decade, there has been a growing recognition of the river basin's complexity as a hydrological, ecological, economic, political, and social system. Therefore, analyzing its research hotspots and trends helps to anticipate future research directions. This study utilized bibliometric software (such as VOSviewer and CiteSpace) to analyze the articles and research trends related to the ecological environment of the Yellow River Basin over the past 11 years (2014–2024). The results indicate that a total of 2096 articles have been published on this topic, with an almost annual increase in publications. Keyword co-occurrence and clustering network analysis indicate that the middle and lower reaches of the Loess Plateau, the delta, and the water quality and flow changes in the Yellow River Basin have been long-term research focuses. Climate change plays a dominant role in Yellow River runoff variation. In recent years, water quality has steadily improved, although delta erosion issues remain unresolved. Research on the sustainable development and ecosystem services of the Yellow River Basin has become a recent trend. With continuous policy development, refinement, and advancements in research, significant progress has been made in enhancing ecosystem services and achieving sustainable development in the Yellow River Basin. Regarding international collaboration, China, the United States, Australia, the United Kingdom, and Germany rank among the top five, with the most intensive collaborations occurring between China and the US, the UK, and Germany. [ABSTRACT FROM AUTHOR]

Anammox bacteria can remove ammonium directly, which is different from what was previously believed. This is an important process for the global nitrogen cycle. Anammox bacteria were first identified in sewage treatment systems and were later proven to exist widely in natural ecosystems. To better understand the relationship between the anammox reaction and different systems, and to maintain the stability of the nitrogen cycle, anammox functional microorganisms found in different natural environments were summarized. In addition, anammox nitrogen production rate and the contribution of anammox to nitrogen were discussed under different ecological environments. A literature analysis showed that the contribution rate of nitrogen removal of anammox was the highest in the Terrestrial ecosystem, up to 87.5%. The Terrestrial ecosystem is more likely to form an anoxic or even anaerobic environment conducive to anaerobic ammoxidation. Therefore, the control of DO is an important factor in the activity of anaerobic ammoxidation. Other environmental factors affecting the contribution of anammox to nitrogen removal include temperature, pH, organic matter content, inorganic nitrogen concentration, and salinity. However, the dominant influencing factors of anammox reactions in different ecosystems are evidently different. Therefore, the mechanism of the impact of different environmental factors on the anaerobic ammonia oxidation process is necessary to discuss. This provides a scientific basis for the global nitrogen cycle and is of great significance to improve nitrogen's biogeochemical cycle in the ecosystem. [ABSTRACT FROM AUTHOR]

To assess the application potential of sewage sludge biochar produced by industrial-scale pyrolysis (ISB), the release characteristics of nutrients (NH 4 +, PO 4 3−, K, Ca, Mg and Fe) and heavy metals (Mn, Cu, Zn, Pb, Ni and Cr) were investigated. Their release amounts increased with decreasing initial pH and increasing solid-liquid ratios (R S-L) and temperature. The release types of NH 4 +, K, Mg, and Mn were diffusion/dissolution, while those of Cu, Zn, Pb, Ni, and Cr were diffusion/resorption. The release types of PO 4 3− and Ca varied with initial pH and R S-L , respectively. The chemical actions played dominant roles in their release, while particle surface diffusion and liquid film diffusion determined the rates of diffusion and resorption phases, respectively. The release of NH 4 +, PO 4 3−, K, Ca, Mg, Mn and Zn was a non-interfering, spontaneous (except PO 4 3−), endothermic, and elevated randomness process. The release efficiency of NH 4 +, PO 4 3− and K met the Chinese standard for slow-release fertilizers, while the total risk of ISB was low. The eutrophication and potential ecological risks of ISB were acceptable when the dose was less than 3 g L−1 and the initial pH was no lower than 3. In conclusion, ISB had potential as a slow-release fertilizer and adsorbent. • Release behavior of nutrients and HMs significantly relied on initial pH, R S-L and T. • Pseudo-secondary kinetic model better described the release of nutrients and HMs. • Their release was a non-interfering, spontaneous, endothermic and entropic process. • Release rates and HSEI confirmed ISB's potential as a slow-release fertilizer. • ISB could be as an adsorbent for water treatment (initial pH ≥ 3, dose <3 g L−1). [ABSTRACT FROM AUTHOR]