Lipid-containing wastewaters, such as those arising from dairy processing, are frequently discharged at temperatures ≤ 20°C. Their valorization at low ambient temperatures offers opportunities to expand the application of high-rate anaerobic wastewater treatment toward achieving energy neutrality by minimizing the energy demand for heating. Lipid hydrolysis generates long-chain fatty acids (LCFAs), which incur operational challenges and hinder stable bioreactor operation by inducing sludge flotation and washout, coupled with the added challenge of treatment at lower temperature (20°C). These challenges are tackled together uniquely during the treatment of LCFA-rich synthetic dairy wastewater (SDW) (33% COD-LCFA) through de novo formed microbial granular sludge within the dynamic sludge chamber–fixed film (DSC-FF) reactor. The novel reactor design facilitated sludge retention for the entire operational period of 150 days by containing settled, flotating, and LCFA-encapsulated granular sludge and biofilm within a single module. High COD removal efficiencies (87–98%) were achieved in the three replicated DSC-FF reactors, along with complete LCFA removal at 18–72 h HRT (LCFA loading rate of 220–890 mgCOD-LCFA/L⋅day) and partial LCFA removal at 12 h HRT (LCFA loading rate of 1333 mgCOD-LCFA/L⋅day). The high removal efficiencies of unsaturated and saturated LCFAs achieved are reported for the first time during continuous anaerobic wastewater treatment at low temperatures (20°C). Moreover, de novo granulation was achieved within 8 days from a combination of inoculum mixtures at a high LCFA concentration (33% COD-LCFA) in SDW. The results demonstrate the feasibility of the DSC-FF reactor for treating LCFA-rich wastewaters at discharge temperatures and offer potential for expanded and more energetically productive anaerobic valorization of lipid-rich wastewater.

含脂废水（如乳制品加工产生的废水）通常在≤20°C的温度下排放。它们在低环境温度下的平衡化提供了机会，可以通过最大限度地减少加热的能源需求，来扩大高速率厌氧废水处理的应用，以实现能源中和。脂质水解产生长链脂肪酸（LCFA），通过引发污泥浮选和冲洗，再加上在较低温度（20°C）下处理的挑战，招致了操作挑战并阻碍了生物反应器的稳定运行。在处理富含LCFA的合成乳品废水（SDW）（33％COD-LCFA）的过程中，这些挑战可以通过独特方式共同解决从头在动态污泥室固定膜（DSC-FF）反应器内形成微生物颗粒污泥。通过将沉降的，浮选的和LCFA包封的颗粒污泥和生物膜包含在单个模块中，新颖的反应器设计有助于在150天的整个操作期间内保持污泥的沉积。在三个重复的DSC-FF反应器中实现了高的COD去除效率（87-98％），以及在HRT的18-72 h（LCFA负载率为220-890 mgCOD-LCFA /L⋅day）和部分分馏塔中完全LCFA去除HRT在12 h时去除LCFA（LCFA负载率为1333 mgCOD-LCFA / L·天）。在低温（20°C）连续厌氧废水处理过程中，首次报道了实现的不饱和和饱和LCFA的高去除效率。此外，从头在SDW中，在高LCFA浓度（33％COD-LCFA）下混合接种混合物，可在8天内实现制粒。结果证明了DSC-FF反应器在排放温度下处理富含LCFA的废水的可行性，并为扩大和更富能量地生产富含脂质的废水提供了潜力。