|
|
低基质CANDAN-HAP颗粒表层矿化与结构响应
|
Abstract:
为揭示低基质条件下CANDAN-HAP颗粒污泥在矿化增强过程中的结构演化特征及其潜在影响，文章以不同运行阶段颗粒污泥为对象，采用VSS/SS测定、体式显微镜、扫描电子显微镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)等方法，对颗粒宏观外观、微观晶体形貌、元素分布及矿物相变化进行分析。结果表明，在92 d运行过程中，体系脱氮功能总体保持稳定，磷去除随pH由7.5提高至8.1。随着矿化增强，颗粒污泥VSS/SS由76.3%降至52.0%和33.8%；SVI降低，表明无机组分累积促进了颗粒致密化和沉降性能改善。颗粒表面由相对均一的生物性外观逐渐转变为白化、粗糙化并伴有结节状沉积的复合外观；SEM-EDS结果显示，颗粒表层由致密微生物聚集结构逐步发展为Ca-P富集沉积，并在后期形成大面积板状晶体堆积。XRD半定量分析表明，阶段三31？~33？ HAP主特征峰区积分面积较阶段二提高约8.7%，说明HAP相关晶相的相对衍射信号增强。总体来看，低基质CANDAN-HAP颗粒表层矿化经历了由弱沉积、局部富集到晶体成熟的阶段性演化路径；适度矿化有利于颗粒致密化和磷固定，但后期表层晶体堆积可能增强结构异质性，并带来潜在传质和脆化风险。
To reveal the structural evolution characteristics and potential impacts of CANDAN-HAP particle sludge during the mineralization enhancement process under low substrate conditions, using different operational stages of the particle sludge as the objects, methods such as VSS/SS determination, body-type microscopes, scanning electron microscopes (SEM), energy-dispersive X-ray analysis (EDS), and X-ray diffraction (XRD) were employed to analyze the macroscopic appearance, microscopic crystal morphology, element distribution, and mineral phase changes of the particles. The results showed that during the 92-day operation, the nitrogen removal function of the system remained stable overall, and phosphorus removal increased as pH increased from 7.5 to 8.1. With mineralization enhancement, the VSS/SS of the particle sludge decreased from 76.3% to 52.0% and 33.8%, and SVI decreased, indicating that the accumulation of inorganic components promoted the densification of the particles and the improvement of their sedimentation performance. The particle surface gradually changed from a relatively uniform biological appearance to a bleached, roughened, and nodular deposition composite appearance. The SEM-EDS results showed that the surface of the particles gradually developed from a dense microbial aggregation structure to Ca-P-enriched deposition, and in the later stage, large-area plate-like crystal accumulations were formed. XRD semi-quantitative analysis indicated that the integrated area of the main HAP characteristic peak region at 31？~33？ in Stage III increased by approximately 8.7% compared with Stage II, suggesting enhanced relative diffraction signals of HAP-related crystalline phases. Overall, the surface mineralization of low-substrate CANDAN-HAP particles underwent a phased evolution path from weak deposition, local enrichment to crystal maturity; moderate mineralization was beneficial for particle
| [1] | Lin, L., Luo, Z., Zhang, Y., Ren, Y. and Li, Y. (2023) Partial Denitrification-Anammox Granular Sludge Domesticated from High-Strength Anammox Granules and the High-Efficiency Performance in Treating Low-Nitrogen Wastewater. Chemical Engineering Journal, 477, Article 147281. https://doi.org/10.1016/j.cej.2023.147281 |
| [2] | Magrí, A., Company, E., Gich, F. and Colprim, J. (2021) Hydroxyapatite Formation in a Single-Stage Anammox-Based Batch Treatment System: Reactor Performance, Phosphorus Recovery, and Microbial Community. ACS Sustainable Chemistry & Engineering, 9, 2745-2761. https://doi.org/10.1021/acssuschemeng.0c08036 |
| [3] | Boleij, M., Seviour, T., Wong, L.L., van Loosdrecht, M.C.M. and Lin, Y. (2019) Solubilization and Characterization of Extracellular Proteins from Anammox Granular Sludge. Water Research, 164, Article 114952. https://doi.org/10.1016/j.watres.2019.114952 |
| [4] | Xue, Y., Ma, H., Kong, Z. and Li, Y. (2021) Formation Mechanism of Hydroxyapatite Encapsulation in Anammox-HAP Coupled Granular Sludge. Water Research, 193, Article 116861. https://doi.org/10.1016/j.watres.2021.116861 |
| [5] | Song, Y., Lin, L., Qi, W., Sasaki, O. and Li, Y. (2023) Anammox-Mediated Hydroxyapatite Granules: Physicochemical Properties, 3D Hierarchy, and Biofilm Thickness. Environmental Science & Technology, 57, 10242-10251. https://doi.org/10.1021/acs.est.3c00596 |
| [6] | Fang, J., Lan, Y., Du, R., Ren, J., Li, X., Fan, X., et al. (2024) Understanding Partial Denitrification-Hydroxyapatite (PD-HAP) Coupled Granules to Enhance Process Stability and Phosphorus Removal by Investigating the Size Effect of Granules. Chemical Engineering Journal, 498, Article 155412. https://doi.org/10.1016/j.cej.2024.155412 |
| [7] | Ma, H., Zhang, Y., Xue, Y., Kubota, K. and Li, Y. (2021) Efficient Phosphorus Recovery by Enhanced Hydroxyapatite Formation in a High Loading Anammox Expanded Bed Reactor at 15˚C. Chemical Engineering Journal, 425, Article 130636. https://doi.org/10.1016/j.cej.2021.130636 |
| [8] | Li, Z., Li, D., Guo, H., et al. (2023) Uncover the Differences between Mineralized and Non-Mineralized Anammox Granular Systems from the Perspective of Physicochemical, Rheological Properties and Microbial Community. Chemical Engineering Journal, 474, Article 146020. |
| [9] | Cao, L., Yang, Y., Xue, Y., Ma, H., Li, Y. and Hu, Y. (2023) A Review of Efficient Nitrogen Removal and Phosphorus Recovery by Anammox-Hydroxyapatite Based Processes: Challenges and Opportunities. Journal of Environmental Chemical Engineering, 11, Article 111103. https://doi.org/10.1016/j.jece.2023.111103 |
| [10] | Wei, L., Hu, Y., Xue, Y., Tian, W., Xue, Y. and Chen, R. (2024) Granular Sludge Characterization and Microbial Response in a Hydroxyapatite (HAP)-Anammox Coupled Process at Different Nitrogen Loading Rates. Journal of Water Process Engineering, 64, Article 105582. https://doi.org/10.1016/j.jwpe.2024.105582 |
| [11] | Chen, L., Wu, Z., Niu, J., Wang, Y., Cai, M., et al. (2025) Simultaneous Nitrogen Removal and Phosphorus Recovery in Granular Sludge-Based Partial Denitrification/Anammox-Hydroxyapatite Precipitation (PD/A-HAP) Process under Low C/N Ratio and Dissolved Oxygen Limitation. Bioresource Technology, 419, Article 132045. https://doi.org/10.1016/j.biortech.2025.132045 |
| [12] | Lan, Y., Du, R., Fan, X., Cao, S. and Peng, Y. (2023) Simultaneous Nitrite Production and Phosphorus Removal by Partial Denitrification-Hydroxyapatite (PD-HAP) Coupled Process from High-Nitrate Wastewater. Chemical Engineering Journal, 474, Article 145428. https://doi.org/10.1016/j.cej.2023.145428 |
