Chemical fertilizer is widely used in agricultural fertilization, but over-fertilization has caused soil quality degradation. Some studies have shown that the application of organic fertilizer is beneficial to soil quality, but there are few studies researching the long-term organic fertilizer application effect on tea plantation soil. In this paper, we studied the physical and chemical properties and microbial communities of tea plantation soil through long-term field experiments by applying organic fertilizer with equal nitrogen amounts. The experiment showed that the soil’s physical and chemical properties were improved after long-term application of total organic fertilizer. Respectively, the soil organic matter (SOM), available potassium (K), available zinc (Zn), available copper (Cu), and pH were significantly enhanced, the soil bulk density was significantly increased, the water-stable aggregates were improved, the soil microbial diversity was increased. It was found that the main bacteria in tea soil were Proteobacteria, Acidobacteria, and Actinobacteria. Moreover, results from redundancy analysis showed t hat t he S OM ( p = 0 .001), A lkali h ydrolyzed n itrogen ( p = 0 .049) a nd p H ( p = 0 .008) h ad significant effects on the soil bacterial community composition. Thus SOM increased the relative richness of non-dominant bacteria, such as Bacteroidetes, Gemmatimonadestes, and Firmicutes. Overall, our results suggest that the use of organic fertilizer instead of chemical fertilizer could effectively improve the quality of tea plantation soil.

The increasing generation of industrial solid wastes, such as red mud and phosphogypsum, poses significant environmental challenges due to their complex chemical compositions and low utilization rates. This study aims to develop an innovative composite material by combining RM and PG, modified with ferric chloride (FeCl₃) and sodium silicate (Na₂SiO₃), to address their environmental risks and enhance their potential for soil and ecological remediation. The modification mechanisms and immobilization of toxic ions were investigated through leaching behavior analysis and advanced microscopic techniques, including BET and XRD. Under the optimal ratio (RM:PG = 7:3), the composite material exhibited excellent performance, with stable pH (8.03), low electrical conductivity (4.89 mS/cm), and significantly reduced concentrations of phosphate (PO₄³⁻: 0.36 mg/L) and fluoride ions (F⁻: 1.34 mg/L), achieving an upgrade from industrial Class II to Class I slag. The modification process increased the specific surface area, optimized pore structure, and enhanced surface activity and structural stability. Pot experiments demonstrated that the modified composite supported normal plant growth, with leachate meeting Grade I wastewater discharge standards. This study not only provides a sustainable approach for the utilization of RM and PG, but also offers valuable insights into the development of eco-friendly materials for soil remediation and ecological restoration, benefiting both the scientific community and environmental management practices.

Large volumes of coal mine drainage sludge (CMDS), a byproduct of acid mine drainage (AMD) treatment, impose both environmental and operational burdens. This review comprehensively evaluates the potential of CMDS as a sustainable resource and introduces a novel integrated framework covering its formation mechanisms, physicochemical properties, environmental risks, and application pathways. Rich in iron, aluminum, and manganese oxides, CMDS features a high specific surface area and porosity, making it suitable for use as an adsorbent. Pretreated CMDS can adsorb arsenic at capacities reaching 67 mg g ^− 1 , with strong desorption and reusability. When applied as an iron source in Fenton-like oxidation, it achieves up to 98% chemical oxygen demand and total organic carbon removal. In combination with calcium-based wastes, it significantly reduces As, Cu, and Pb leaching by more than 90% in soil. Nevertheless, concerns over secondary metal release persist. This study discusses these limitations and proposes a “dual-core” strategy integrating AMD treatment optimization with targeted CMDS modification, offering a new direction for ecological remediation and circular resource utilization in mining-impacted areas.