Federal University of Santa Catarina, Trindade University Campus, Sanitary and Environmental Engineering Department, Florianópolis, Brazil.
Federal University of Santa Catarina, Trindade University Campus, Sanitary and Environmental Engineering Department, Florianópolis, Brazil.
J Environ Manage. 2020 Jun 1;263:110394. doi: 10.1016/j.jenvman.2020.110394. Epub 2020 Mar 10.
Alginate-like exopolymers (ALE) are present in the extracellular polymeric substances (EPS) of biological sludge such as aerobic granular sludge (AGS). The recovery of ALE from excess sludge produced by wastewater treatment plants (WWTP) is a relevant approach for the recovery of valuable products of industrial interest. However, little is known about dynamics of ALE content in sludge and associated factors. Thus, this study aimed at assessing the dynamics of EPS and ALE in terms of content, some chemical properties and influencing environmental factors along granulation in a sequencing batch reactor treating municipal wastewater. Results indicated that the EPS content was not correlated with the development of AGS, while the ALE content was higher, more stable and steadily increased after granulation achievement. Overall, 236 ± 27 mg VS/g VS was recovered from AGS and 187 ± 94 mg VS/g VS from flocs. However, the lower ALE content in flocs may be compensated by the higher sludge production rate in activated sludge systems. Principal component analysis (PCA) revealed that ALE content positively correlates with the nutrient and organic substrate conversion, and with the fraction of large AGS. Microbial analyses indicated that a stable microbial community composition was associated with a higher and more stable ALE content. ALE recovered from both flocs and AGS was endowed with hydrogel property, and no clear difference in their elemental composition and functional groups was observed. Therefore, our study provides insights about quantitative and qualitative aspects of ALE which are helpful for the improvement of waste biological sludge valorization.
藻酸盐样胞外聚合物 (ALE) 存在于好氧颗粒污泥 (AGS) 等生物污泥的细胞外聚合物物质 (EPS) 中。从污水处理厂 (WWTP) 产生的剩余污泥中回收 ALE 是回收具有工业价值的有价值产品的一种相关方法。然而，人们对污泥中 ALE 含量的动态及其相关因素知之甚少。因此，本研究旨在评估 EPS 和 ALE 在含量、一些化学性质和影响环境因素方面的动态，这些因素与市政废水处理的序批式反应器中的颗粒化有关。结果表明，EPS 含量与 AGS 的发展没有相关性，而 ALE 含量在颗粒化后更高、更稳定且稳步增加。总的来说，从 AGS 中回收了 236±27mg VS/g VS，从絮体中回收了 187±94mg VS/g VS。然而，絮体中较低的 ALE 含量可能会被活性污泥系统中较高的污泥产率所补偿。主成分分析 (PCA) 表明，ALE 含量与营养物和有机底物的转化以及大 AGS 的分数呈正相关。微生物分析表明，稳定的微生物群落组成与更高和更稳定的 ALE 含量有关。从絮体和 AGS 中回收的 ALE 具有水凝胶特性，其元素组成和官能团没有明显差异。因此，我们的研究提供了有关 ALE 的定量和定性方面的见解，有助于提高废生物污泥的增值。
