Alessio Fenu, Lennert Dockx, Sandra Van Damme, Frederik Wynants, Verhaeghe Kirke, Koen Van Laer, Joris Roels, Rosalia Delgado
Aquafin NV, Dijkstraat 8, Aartselaar, Belgium E-mail:
Aquafin NV, Dijkstraat 8, Aartselaar, Belgium.
Water Sci Technol. 2023 Aug;88(3):645-657. doi: 10.2166/wst.2023.240.
Glycerol is commonly employed for denitrification purposes in full-scale wastewater treatment. In non-acclimatized biomass, the glycerol is very inefficient resulting in a high C/N ratio and low-standard denitrification rates. The acclimatization is driven by the microbial enrichment of Saccharimonadales and Propionibacteriales as found in different sampled municipal sludges flanking the dominant presence of Burkholderiales. The selective strategy is based on a very efficient process in terms of C/N ratios and standard denitrification rates, but it leads to nitrite accumulation. As a result, severe and unexpected nitrous oxide emissions were found in full-scale with emission factors up to 2.5% kgNO (kgKJN). Simultaneous dosage of isobutirate in a full-scale experiment could counter the nitrous oxide emissions. As nitrous oxide emissions were found proportional to the dosed glycerol-based COD, the authors suggest that, in case of acclimatization of biomass to glycerol, an emission factor based on the dosed COD should substitute the general nitrous oxide emission factors based on incoming or removed nitrogen to the plant.
甘油通常用于大规模废水处理中的反硝化过程。在未经驯化的生物量中，甘油的利用效率很低，导致碳氮比很高且反硝化速率达不到标准。驯化过程是由糖单胞菌目和丙酸杆菌目的微生物富集驱动的，这在不同采样的城市污泥中都有发现，而伯克霍尔德氏菌目占主导地位。这种选择性策略在碳氮比和标准反硝化速率方面基于一个非常高效的过程，但它会导致亚硝酸盐积累。结果，在大规模处理中发现了严重且意想不到的一氧化二氮排放，排放因子高达2.5% kgNO（kgKJN）。在一个大规模实验中同时投加异丁酸盐可以抵消一氧化二氮的排放。由于发现一氧化二氮排放与投加的基于甘油的化学需氧量成正比，作者建议，在生物量适应甘油的情况下，基于投加化学需氧量的排放因子应替代基于进入或去除到工厂的氮的一般一氧化二氮排放因子。
