Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
Department of Civil and Environmental Engineering, University of Florence, Via di Santa Marta 3, 50139 Florence, Italy.
Sci Total Environ. 2021 Jan 20;753:142051. doi: 10.1016/j.scitotenv.2020.142051. Epub 2020 Sep 2.
Granular sludge (GS) is a special self-aggregation biofilm. Extracellular polymeric substances (EPS) are mainly associated with the architectural structure, rheological behaviour and functional stability of fine granules, given that their significance to the physicochemical features of the biomass catalysing the biological purification process. This review targets the EPS excretion from GS and introduces newly identified EPS components, EPS distribution in different granules, how to effectively extract and recover EPS from granules, key parameters affecting EPS production, and the potential applications of EPS-based biomaterials. GS-based EPS components are highly diverse and a series of new contents are highlighted. Due to high diversity, emerging extraction standards are proposed and recovery process is capturing particular attention. The major components of EPS are found to be polysaccharides and proteins, which manifest a larger diversity of relative abundance, structures, physical and chemical characteristics, leading to the possibility to sustainably recover raw materials. EPS-based biomaterials not only act as alternatives to synthetic polymers in several applications but also figure in innovative industrial/environmental applications, including gel-forming materials for paper industry, biosorbents, cement curing materials, and flame retardant materials. In the upcoming years, it is foreseen that productions of EPS-based biomaterials from renewable origins would make a significant contribution to the advancement of the circular economy.
颗粒污泥（GS）是一种特殊的自聚集生物膜。胞外聚合物（EPS）主要与细颗粒的结构、流变行为和功能稳定性相关联，因为它们对生物催化生物净化过程的生物质的物理化学特性具有重要意义。本综述针对 GS 中 EPS 的排泄进行了研究，并介绍了新发现的 EPS 成分、不同颗粒中 EPS 的分布、如何从颗粒中有效提取和回收 EPS、影响 EPS 产生的关键参数，以及基于 EPS 的生物材料的潜在应用。GS 基 EPS 成分具有高度多样性，并突出了一系列新内容。由于多样性高，提出了新的提取标准，并特别关注回收过程。发现 EPS 的主要成分是多糖和蛋白质，它们表现出更大的相对丰度、结构、物理和化学特性多样性，从而有可能可持续地回收原材料。基于 EPS 的生物材料不仅在几个应用中替代了合成聚合物，而且在创新的工业/环境应用中也具有重要作用，包括造纸工业用的凝胶形成材料、生物吸附剂、水泥固化材料和阻燃材料。在未来几年，预计从可再生资源生产基于 EPS 的生物材料将为循环经济的发展做出重大贡献。
