College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, China.
State Key Laboratory Breeding Base of Coal Science and Technology Co-founded by Shanxi Province and the Ministry of Science and Technology, Taiyuan University of Technology, Taiyuan, China.
Sci Rep. 2017 Feb 17;7:42887. doi: 10.1038/srep42887.
Most studies on the production of volatile fatty acids (VFAs) from waste activated sludge (WAS) digestion have focused on operating conditions, pretreatments and characteristic adjustments. Conditioning by extra carbon sources (ECS), normally added in a solid form, has been reported to be an efficient approach. However, this has caused considerable waste of monomeric sugars in the hydrolysate. In this study, the effects of two added forms (pretreated straw (S) and hydrolyzed liquid (L)) of cornstover (CS) on WAS acidification were investigated. To obtain different cellulosic compositions of CS, low-thermal or autoclaved assisted alkaline (TA or AA) pretreatments were conducted. The results showed that AA-L test achieved the highest VFAs value (653 mg COD/g VSS), followed by AA-S (613 mg COD/g VSS). These values were 12% and 28% higher, respectively, than that obtained in the TA-L and TA-S tests. Meanwhile, higher percentages of acetic acid were observed after AA pretreatment (~62% versus ~53% in TA). The added forms of CS played an important role in structuring the innate microbial community in the WAS, as shown by high-throughput sequencing and canonical correspondence analysis. The findings obtained in this work may provide a scientific basis for the potential implementation of co-digesting WAS with ECS simultaneously obtaining energy and high value-added products.
大多数关于从废活性污泥（WAS）消化中生产挥发性脂肪酸（VFAs）的研究都集中在操作条件、预处理和特性调整上。通过额外的碳源（ECS）进行调理，通常以固体形式添加，已被报道是一种有效的方法。然而，这导致水解物中单体糖的大量浪费。在这项研究中，考察了玉米秸秆（CS）的两种添加形式（预处理秸秆（S）和水解液体（L））对 WAS 酸化的影响。为了获得 CS 的不同纤维素组成，进行了低热或高压釜辅助碱性（TA 或 AA）预处理。结果表明，AA-L 试验获得了最高的 VFAs 值（653mg COD/g VSS），其次是 AA-S（613mg COD/g VSS）。与 TA-L 和 TA-S 试验相比，这两个值分别提高了 12%和 28%。同时，AA 预处理后观察到乙酸的比例更高（62%比 TA 中的53%）。CS 的添加形式在构建 WAS 中固有微生物群落方面起着重要作用，这可以通过高通量测序和典范对应分析得到证明。这项工作的发现可能为同时获得能源和高附加值产品的同时用 ECS 共消化 WAS 提供科学依据。
