ABSTRACT:

Lipids in sewage sludge are considered to be high-class raw materials for biodiesel or other valuable products. We profiled the characteristics and assessed the reutilization potential of lipids from different sludge sources, including sludge from the primary sedimentation tank (PST sludge) and sludge from the secondary sedimentation tank in a conventional activated sludge system (CAS sludge), as well as sludge from ultrashort-sludge retention time (SRT) activated sludge systems with different SRTs (USAS sludge, with SRTs of 0.5, 1.0, 2.0, 3.0 and 4.0 d). The results showed that the lipids in the sludges were mainly composed of cellular lipids, free fatty acids (FFAs), wax and gum. The highest lipid content was found in the PST sludge (156.8 ± 11.9 mg/g, dry basis), followed by the USAS sludges (67.9 ± 11.0–132.2 ± 11.8 mg/g) and the CAS sludge (46.0 ± 16.5 mg/g). Lipid species such as Cer, So, PE, PC, and TG were abundant, comprising over 80% of the cellular lipids in the sludges. With higher lipid contents, the PST sludge and USAS sludge (0.5 d SRT) were suggested to have a higher reutilization potential for use in producing biodiesel. In addition, the CAS sludge was promising for resource reutilization and energy recovery due to the large amount of excess sludge.

摘要:

污泥中所含有的脂质可用于生产生物柴油或其他高价值产品。本文研究了不同来源污泥的脂质组成特征和再利用潜力，这些污泥包括传统活性污泥系统中初沉池（PST污泥）和二沉池（CAS污泥）中的污泥以及具有不同SRT超低龄活性污泥系统（USAS污泥，SRT分别为0.5、1.0、2.0、3.0和4.0 d）。结果表明，污泥中的脂质主要由细胞脂质，游离脂肪酸（FFAs），蜡和树胶组成。 PST污泥中的脂质含量最高（156.8±11.9 mg/g，干基），其次是USAS污泥（67.9±11.0-132.2±11.8 mg/g）和CAS污泥（46.0±16.5 mg/g） ）。 Cer，So，PE，PC和TG等脂质种类丰富，占污泥中细胞脂质的80％以上。 PST污泥和USAS污泥（0.5 d SRT）具有较高的脂质含量和更高的再利用潜力。此外，由于CAS污泥总量非常大且脂质组成可观，CAS污泥有望用于资源再利用和能量回收。

原载于Scientific Reports（2020 Impact Factor = 4.01）

原文链接：https://www.nature.com/articles/s41598-020-69855-6