Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province / School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province / School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
J Environ Manage. 2024 Sep;368:122210. doi: 10.1016/j.jenvman.2024.122210. Epub 2024 Aug 14.
The positive contributions of carriers to aerobic granulation have been wildly appreciated. In this study, as a way resource utilization, the dredged sediment was thermally-treated to prepared as carriers to promote aerobic granular sludge (AGS) formation and stability. The system was started under low superficial gas velocity (SGV, 0.6 cm/s)for a lower energy consumption. Two sequencing batch reactors (SBR) labeled R1 (no added carriers) and R2 (carriers added), were used in the experiment. R2 had excellent performance of granulation time (shortened nearly 43%). The maximum mean particle size at the maturity stage of AGS in R2 (0.545 mm) was larger compared to R1 (0.296 mm). The sludge settling performance in R2 was better. The reactors exhibited high chemical oxygen demand (COD) and ammonia nitrogen (NH-N) removal rates. The total phosphorus (TP) removal rate in R2 was higher than R1 (almost 15% higher) on stage II (93-175d). R2 had a higher microbial abundance and dominant bacteria content. The relative abundance of dominant species was mainly affected by the carrier. However, the enrichment of dominant microorganisms and the evolution of subdominant species were more influenced by the increase of SGV. The results indicated that the addition of carriers induced the secretion of extracellular polymeric substances (EPS) by microorganisms and accelerated the rapid formation of initial microbial aggregates. This work provided a low-cost method and condition to enhance aerobic granulation, which may be helpful in optimizing wastewater treatment processes.
载体对好氧颗粒化的积极贡献得到了广泛的认可。在这项研究中，为了资源利用，将疏浚沉积物进行热处理，制备成载体以促进好氧颗粒污泥（AGS）的形成和稳定性。该系统在低表面气速（SGV，0.6cm/s）下启动，以降低能耗。实验中使用了两个序批式反应器（SBR），分别标记为 R1（未添加载体）和 R2（添加载体）。R2 具有出色的颗粒化时间性能（缩短了近 43%）。AGS 在成熟阶段的最大平均粒径在 R2（0.545mm）中比 R1（0.296mm）更大。R2 的污泥沉降性能更好。反应器表现出高的化学需氧量（COD）和氨氮（NH-N）去除率。在第二阶段（93-175d），R2 的总磷（TP）去除率高于 R1（高 15%左右）。R2 具有更高的微生物丰度和优势细菌含量。优势种的相对丰度主要受载体影响。然而，优势微生物的富集和亚优势种的演替更多地受到 SGV 增加的影响。结果表明，载体的添加诱导微生物分泌胞外聚合物（EPS），并加速初始微生物聚集体的快速形成。这项工作提供了一种低成本的方法和条件来增强好氧颗粒化，这可能有助于优化废水处理工艺。
