Ossiansson Elin, Persson Frank, Bengtsson Simon, Cimbritz Michael, Gustavsson David J I
VA SYD, Box 191, SE-20121 Malmö, Sweden; Chalmers University of Technology, Dep. of Architecture and Civil Engineering, SE-412, 96 Gothenburg, Sweden.
Chalmers University of Technology, Dep. of Architecture and Civil Engineering, SE-412, 96 Gothenburg, Sweden.
Water Res. 2023 Aug 15;242:120181. doi: 10.1016/j.watres.2023.120181. Epub 2023 Jun 7.
Primary treatment of municipal wastewater by rotating belt filtration followed by hydrolysis and acidogenic fermentation of the filter primary sludge (FPS) at ambient temperature was studied at pilot-scale during one year. The seasonal variations of volatile fatty acids (VFAs), nutrient release and soluble COD production as well as microbial community assembly were assessed, leading to novel findings for fermentation at ambient temperature. The reproducibility of VFA production performance was first established by operating the two fermentation reactors under the same conditions, showing similar results regarding VFA production and microbial community structure. One year of operation at 5 d retention time (RT) and 16-29 °C resulted in an average VFA yield of 180±35 mg COD/g VS and soluble COD yield of 242±40 mg COD/g VS. The VFA formation was temperature-dependent, with ϴ=1.033±0.005 ( [Formula: see text] . The seasonal variations of the acetic and propionic acid productions were pronounced, whereas the productions of VFAs with longer chains were more stable regardless of temperature. The community structure of the reactor microbiomes was also clearly affected by season and temperature and linked with the production spectrum of VFAs. The ammonium and phosphate releases were stable during the year, leading to a decrease in ratios of soluble COD to NH-N and PO-P during winter. The soluble COD yield was 11% and 27% higher at 5 d RT compared to 3 and 2 d RT respectively, but the corresponding volumetric productivities were lower. The dissimilarities between microbiomes in influent FPS and fermenters were significant even at a short RT of 2 d, and increased with longer RT of 3 and 5 d, primarily caused by selection of bacteria within Bacteroidota in the fermentation reactors.
在中试规模下，对城市污水进行了为期一年的初级处理，处理工艺为旋转带式过滤，随后在常温下对过滤后的初级污泥（FPS）进行水解和产酸发酵。评估了挥发性脂肪酸（VFA）、养分释放、可溶性化学需氧量（COD）产生以及微生物群落组装的季节变化，得出了关于常温发酵的新发现。首先通过在相同条件下运行两个发酵反应器，确定了VFA生产性能的可重复性，在VFA产量和微生物群落结构方面显示出相似的结果。在5天停留时间（RT）和16 - 29°C下运行一年，平均VFA产量为180±35 mg COD/g VS，可溶性COD产量为242±40 mg COD/g VS。VFA的形成与温度有关，ϴ = 1.033±0.005（[公式：见正文]）。乙酸和丙酸产量的季节变化明显，而长链VFA的产量在不同温度下更稳定。反应器微生物群落的结构也明显受季节和温度影响，并与VFA的生产谱相关。全年铵和磷的释放稳定，导致冬季可溶性COD与NH - N和PO - P的比率降低。与3天和2天RT相比，5天RT时的可溶性COD产量分别高出11%和27%，但相应的体积生产率较低。即使在2天的短RT下，进水FPS和发酵罐中微生物群落之间的差异也很显著，并且随着3天和5天更长RT而增加，这主要是由发酵反应器中拟杆菌门内细菌的选择引起的。
