Psychrophilic and mesophilic anaerobic treatment of synthetic dairy wastewater with long chain fatty acids: Process performances and microbial community dynamics

Facilitating the anaerobic degradation of long chain fatty acids (LCFA) is the key to unlock the energy potential of lipids-rich wastewater. In this study, the feasibility of psychrophilic anaerobic treatment of LCFA-containing dairy wastewater was assessed and compared to mesophilic anaerobic treatment. The results showed that psychrophilic treatment at 15 ? was feasible for LCFA-containing dairy wastewater, with high removal rates of soluble COD (>90%) and LCFA (~100%). However, efficient long-term treatment required prior acclimation of the biomass to psychrophilic temperatures. The microbial community analysis revealed that putative syntrophic fatty acid bacteria and Methanocorpusculum played a crucial role in LCFA degradation during both mesophilic and psychrophilic treatments. Additionally, a fungal-bacterial biofilm was found to be important during the psychrophilic treatment. Overall, these findings demonstrate the potential of psychrophilic anaerobic treatment for industrial wastewaters and highlight the importance of understanding the microbial communities involved in the process.

促进长链脂肪酸（LCFA）的厌氧降解，是挖掘富脂质废水能源潜力的核心关键。本研究评估了含LCFA乳制品废水的嗜冷厌氧处理可行性，并与中温厌氧处理进行了对比分析。结果表明，在15℃条件下开展的嗜冷处理可有效处理含LCFA的乳制品废水，溶解性化学需氧量（soluble COD）去除率超90%，LCFA去除率可达约100%。但要实现长期高效处理，需预先将微生物菌群驯化至嗜冷温度环境。微生物群落分析显示，在中温和嗜冷两种处理过程中，潜在的协同营养脂肪酸细菌与甲烷囊菌属（Methanocorpusculum）均在LCFA降解环节发挥了关键作用。此外，研究发现真菌-细菌生物膜在嗜冷处理过程中具有重要意义。总体而言，本研究结果证实了嗜冷厌氧处理在工业废水中的应用潜力，并强调了解析该处理过程所涉及的微生物群落的重要性。