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.
Sci Total Environ. 2023 Apr 1;867:161491. doi: 10.1016/j.scitotenv.2023.161491. Epub 2023 Jan 10.
Malodorous volatile organic compounds (MVOCs) are often the key odorants in determining sludge odor character and odor impact. However, the emission characterization and generation mechanisms of MVOCs from various dewatered sludge have not been sufficiently understood partly due to the diverse and complex composition and low concentration of odorants. In this study, waste activated sludge (WAS) was collected to examine the variation of MVOC emission from sludge after different dewatering treatment in lab-scale trials. The MVOCs were measured using the electronic nose (eNose), headspace gas chromatography-coupled ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that centrifugation treatment promoted the generation of various odorous volatiles. The identified key odorants included dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), geosmin, and p-cresol according to their odor activity values (OAVs). The effects of the enhanced dewatering on volatile production were greater than thickening, however, the key odorants of dewatered sludge using gravity thickening varied more greatly than sludges from centrifuge thickening. The distribution of extracellular polymeric substances (EPS) and variation of microbial community showed correlations with the production of key odorants. Tryptophan-like substances in the inner layer of EPS (LB-EPS and TB-EPS) were better correlated with the key odorants. The bound EPS released by centrifugation may play the role of precursor for odorous microbial volatiles. According to the predicted functions of differential microbial genera, Desulfobulbus (Desulfobacterota), Gordonia (Actinobacteriota), and Hyphomicrobium (Proteobacteria) were associated with the production of DMS, DMDS, and DMTS, while Gordonia and Hyphomicrobium were related to p-cresol production.
发臭的挥发性有机化合物（MVOCs）通常是决定污泥气味特征和气味影响的关键气味物质。然而，由于气味物质的组成多样且复杂，浓度低，各种脱水污泥中 MVOC 的排放特征和产生机制尚未得到充分理解。在这项研究中，采集了废活性污泥（WAS），以在实验室规模试验中检查不同脱水处理后污泥中 MVOC 排放的变化。使用电子鼻（eNose）、顶空气相色谱-离子迁移谱（HS-GC-IMS）和顶空固相微萃取气相色谱-质谱（HS-SPME-GC-MS）测量 MVOCs。结果表明，离心处理促进了各种臭味挥发物的产生。根据气味活性值（OAV），鉴定出的关键气味物质包括二甲基硫（DMS）、二甲基二硫（DMDS）、二甲基三硫（DMTS）、土臭素和对甲酚。增强脱水对挥发性物质产生的影响大于浓缩，然而，重力浓缩的脱水污泥的关键气味物质变化比离心浓缩的污泥变化更大。细胞外聚合物物质（EPS）的分布和微生物群落的变化与关键气味物质的产生有关。EPS 内层的色氨酸样物质（LB-EPS 和 TB-EPS）与关键气味物质的相关性更好。离心释放的结合 EPS 可能对有气味的微生物挥发性物质的前体起作用。根据差异微生物属的预测功能，脱硫弧菌（脱硫杆菌）、戈登氏菌（放线菌）和微菌（变形菌）与 DMS、DMDS 和 DMTS 的产生有关，而戈登氏菌和微菌与对甲酚的产生有关。
