Abstract

Aerobic granular sludge (AGS) is a microbial biofilm self-aggregation, which is effective for nutrient and pollutant removal, through the development of dense microbial layers bound together with extracellular polymeric substances (EPSs). However, long start-up times and granule disintegration are still challenges ahead. An array of external additives, including ion chelating agents, sludge-based enhancers, and magnetic influence have been tested to overcome these barriers. The application of such additives may promote enhanced EPS production, neutralization of charges on the bacterial surface, acts as a core-induced agent, or as a bridge to connect EPSs and cell surfaces. Although additives may improve the granule formation without reducing treatment efficiencies, there are still environmental concerns due to the fate and toxicity of discharged excess sludge. This mini-review identifies an array of external additives and their mechanisms to improve granulation properties, and proposes discussion about the technical and economic viability of these additives.

Key points

• Additives reduce granulation time and repair granule disintegration.

• Biopolymer-based additives fulfill technical and environmental requirements.

• Sludge-based additives are cheap and in line with the resource recovery concept.

• The need for environmental-friendly additives for aerobic granular sludge process.

• External additives affect granular biomass size distribution.

中文翻译：

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添加剂的应用对建立快速稳定的好氧制粒的影响。

摘要

好氧颗粒污泥（AGS）是一种微生物生物膜自聚集体，通过形成与细胞外聚合物（EPS）结合在一起的致密微生物层，可有效去除营养和污染物。然而，长的启动时间和颗粒崩解仍然是未来的挑战。已测试了一系列外部添加剂，包括离子螯合剂，基于污泥的增强剂和磁性影响剂，以克服这些障碍。此类添加剂的应用可以促进增强的EPS产生，中和细菌表面上的电荷，充当核心诱导剂或充当连接EPS和细胞表面的桥梁。尽管添加剂可以改善颗粒的形成而不会降低处理效率，由于排出的过量污泥的命运和毒性，仍然存在环境问题。这份小型综述确定了一系列外部添加剂及其改善造粒性能的机理，并提出了有关这些添加剂的技术和经济可行性的讨论。

关键点

•添加剂可减少制粒时间并修复颗粒崩解。

•基于生物聚合物的添加剂符合技术和环境要求。

•基于污泥的添加剂价格便宜，符合资源回收的概念。

•对好氧颗粒污泥工艺需要环保添加剂。

•外部添加剂影响颗粒状生物量的大小分布。