State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Yangtze River Delta Research Center for Eco-Environmental Sciences, Yiwu, 322000, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Yangtze River Delta Research Center for Eco-Environmental Sciences, Yiwu, 322000, China.
Environ Pollut. 2022 Aug 1;306:119423. doi: 10.1016/j.envpol.2022.119423. Epub 2022 May 7.
Sludge treatment processes are the main source of nuisance odors in wastewater treatment plants. Apart from well-known odorants such as NH and HS, malodorous volatile organic compounds (MVOCs) contribute largely to nuisance odors but are less concerned. In this work, the emission of MVOCs from wastewater sludges at different processing stages was measured, and the effects of dewatering and low-temperature thermal drying on the generation of sludge odor were investigated. The MVOCs were analyzed by olfactory measurements, headspace gas chromatography-coupled ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). Low-temperature thermal drying treatment changed the odor categories and increased the odor intensity (OI) from moderate level (8-9) for raw sludges to strong (>10) for dried sludge. The odor emission capacity of MVOCs, namely the concentration of MVOCs, increased for dried sludge. The major odorants of sludge after different processes included 2-MIB, geosmin, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), hexanal, and decanal according to their odor activity values (OAVs). The bacterial community structures showed a correlation with the key MVOC odorants. Specifically, there was a significant positive correlation between the concentration of key odorants and the relative abundance of the phyla of Actinobacteria and Chloroflexi. Thus, low-temperature thermal drying had a significant effect on odor formation by acting on the microbial community of sludge.
污泥处理过程是污水处理厂产生异味的主要来源。除了众所周知的氨（NH）和硫化氢（HS）等异味物质外，恶臭挥发性有机化合物（MVOCs）也是异味的主要贡献者，但关注度较低。本工作测量了不同处理阶段污水污泥中 MVOCs 的排放，并研究了脱水和低温热干燥对污泥异味产生的影响。通过嗅觉测量、顶空气相色谱-离子迁移谱联用（HS-GC-IMS）和顶空气相固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）对 MVOCs 进行了分析。低温热干燥处理改变了异味类别，使原始污泥的异味强度（OI）从中等水平（8-9）增加到干燥污泥的强烈水平（>10）。干燥污泥中 MVOCs 的异味排放能力，即 MVOCs 的浓度增加。根据其气味活度值（OAV），不同工艺后污泥的主要异味物质包括 2-甲基异莰醇（2-MIB）、土臭素、二甲基二硫醚（DMDS）、二甲基三硫醚（DMTS）、己醛和癸醛。细菌群落结构与关键 MVOC 异味物质存在相关性。具体来说，关键异味物质的浓度与放线菌门和绿弯菌门等微生物群落的相对丰度呈显著正相关。因此，低温热干燥通过作用于污泥微生物群落对异味形成有显著影响。
