Federal University of Pernambuco, Department of Civil and Environmental Engineering, Laboratory of Environmental Sanitation, Av. Acadêmico Hélio Ramos s/n, Recife, 50740-530, Brazil; Institute of Urban Water Management and Environmental Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum, 44801, Germany.
Institute of Urban Water Management and Environmental Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum, 44801, Germany.
Environ Res. 2022 Sep;212(Pt D):113578. doi: 10.1016/j.envres.2022.113578. Epub 2022 May 29.
This study investigated the influence of temperature (20 and 30 °C) on the formation and stability of aerobic granules in sequential batch reactors (SBR). Therefore, two lab-scale SBRs operated at 20 and 30 °C (SBR and SBR) were used. The reactors were fed with municipal wastewater (COD:TN:TP 100:15:1.7), leading to mean organic loading rates (OLR) of 1.3 ± 0.4 kgCOD m day. Both reactors had the same height/diameter ratio of 4.2 and were inoculated with activated sludge from a municipal wastewater treatment plant. The operational conditions were also the same for both temperatures and lasted in stable process parameters for over 100 days. By optimizing the aeration and oxygen concentration, a high removal efficiency of NH-N (∼99%) and COD (∼90%) was achieved in both reactors, despite the poor C:N:P ratio at the influent. Furthermore, a relatively low oxygen concentration of 2 mg L was defined as the set point for the control strategy. Nevertheless, granulation at 30 °C was significantly faster, resulting in more stable sludge volume index (SVI) values (SVI/SVI < 1.1). The granules formed at 30 °C were also larger, more compact, and considerably more stable against system disturbances. However, at higher temperatures, larger granules might be required for nitrate removal because of the increased oxygen diffusion rates. Finally, microbiological 16S rRNA gene amplicon analysis for both systems indicated major differences relatively to the inoculum sludge only for nitrogen-degrading organisms.
本研究考察了温度（20 和 30°C）对序批式反应器（SBR）中好氧颗粒形成和稳定性的影响。因此，使用了两个在 20 和 30°C 下运行的实验室规模 SBR（SBR 和 SBR）。反应器以城市污水（COD：TN：TP 为 100：15：1.7）为进水，导致平均有机负荷率（OLR）为 1.3±0.4 kgCOD m day。两个反应器的高度/直径比均为 4.2，接种自城市污水处理厂的活性污泥。操作条件也在两种温度下相同，并在稳定的工艺参数下持续超过 100 天。通过优化曝气和氧气浓度，在两个反应器中均实现了 NH-N（99%）和 COD（90%）的高去除效率，尽管进水的 C:N:P 比很差。此外，定义 2 mg L 的相对较低氧气浓度作为控制策略的设定点。然而，在 30°C 下的颗粒化速度明显更快，导致更稳定的污泥体积指数（SVI）值（SVI/SVI<1.1）。在 30°C 下形成的颗粒也更大、更紧凑，并且对系统干扰的稳定性大大提高。然而，在较高的温度下，可能需要更大的颗粒来去除硝酸盐，因为氧气扩散速率增加。最后，两个系统的微生物 16S rRNA 基因扩增子分析仅相对于接种污泥表明在氮降解生物方面存在主要差异。
