Huang Dongye, Liu Nana, Guan Chen, Zhang Jingwen, Wang Ruotong, Chen Qiuyu, Tian Fei, Liu Xiaochen, Wu Zhansheng
School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Engineering Research Center of Biological Resources Development and Pollution Control Universities of Shaanxi Province, Key Laboratory of Textile Dyeing Wastewater Treatment Universities of Shaanxi Province, Xi'an Polytechnic University, Xi'an, 710048, China.
State Key Laboratory of Eco-Hydrology in Northwest Arid Regions of China, Xi'an Univ. of Technology, No. 5 Jinhua South Rd., Beilin District, Xi'an, Shaanxi, 710048, China.
Environ Res. 2025 Nov 15;285(Pt 4):122602. doi: 10.1016/j.envres.2025.122602. Epub 2025 Aug 12.
Addressing global phosphorus resource scarcity and low utilization efficiency of traditional phosphorus fertilizers, this study presents an innovative strategy for modifying biochar-based slow-release phosphorus fertilizer (BSPF) with Mg-Al layered double hydroxides (LDH-BSPF), to enhance phosphorus slow-release performance through multi-level synergistic regulation. A novel slow-release system was fabricated via co-pyrolysis technology integrating biomass, phosphorus sources, and LDH. The effects of Mg/Al molar ratios (2:1-5:1) and pyrolysis temperatures (400-600 °C) on material structural properties were systematically investigated. The interlayer structure of LDH significantly optimized the pore architecture of biochar, increasing the BET specific surface area by 1.48-9.94 times, while simultaneously immobilizing phosphorus through mechanisms of interlayer adsorption and chemical bonding. Phosphorus fixation in the LDH-BSPF followed a hierarchical pathway comprising "surface adsorption-interlayer adsorption-pore entrapment". Furthermore, structural evolution of LDH during pyrolysis was found to modulate the slow-release performance. Results from the 28-day static water release experiment demonstrated that 4:1-LDH-BSPF achieved a 36.8 % cumulative phosphorus release rate, representing a 44.6 % decrease relative to unmodified BSPF (66.5 %), with release kinetics primarily following diffusion mechanisms. Comprehensive characterization and phosphorus fractionation analysis confirmed that multi-level phosphate retention-transformation within LDH interlayers, coupled with the synergistic effects of LDH structural modulation on biochar pore architecture and functional groups, constitute the key mechanisms underlying the enhanced slow-release performance. Pot experiments verified that LDH-BSPF significantly outperformed conventional commercial phosphorus fertilizers in promoting pepper growth. This research provides a theoretical basis for developing high-efficiency biochar-based slow-release fertilizers and improving phosphorus utilization efficiency.
针对全球磷资源稀缺以及传统磷肥利用效率低下的问题，本研究提出了一种创新策略，即采用镁铝层状双氢氧化物对生物炭基缓释磷肥（BSPF）进行改性（LDH-BSPF），以通过多级协同调控提高磷的缓释性能。通过整合生物质、磷源和LDH的共热解技术制备了一种新型缓释系统。系统研究了Mg/Al摩尔比（2:1 - 5:1）和热解温度（400 - 600°C）对材料结构性能的影响。LDH的层间结构显著优化了生物炭的孔隙结构，使BET比表面积增加了1.48 - 9.94倍，同时通过层间吸附和化学键合机制固定磷。LDH-BSPF中的磷固定遵循“表面吸附 - 层间吸附 - 孔隙截留”的分级途径。此外，发现热解过程中LDH的结构演变调节了缓释性能。28天静态水释放实验结果表明，4:1-LDH-BSPF的累积磷释放率为36.8%，相对于未改性的BSPF（66.5%）降低了44.6%，释放动力学主要遵循扩散机制。综合表征和磷分级分析证实，LDH层间多级磷酸盐保留 - 转化，以及LDH结构调节对生物炭孔隙结构和官能团的协同作用，构成了缓释性能增强的关键机制。盆栽实验验证了LDH-BSPF在促进辣椒生长方面明显优于传统商业磷肥。本研究为开发高效生物炭基缓释肥料和提高磷利用效率提供了理论依据。
