Effect of chemical oxygen demand load on the nitrification and microbial communities in activated sludge from an aerobic nitrifying reactor

Abstract

In this study, we explored the effect of chemical oxygen demand (COD) load on the nitrification and microbial communities in activated sludge isolated from an aerobic nitrifying tank. The activated sludge was cultured in three different COD groups: L-COD, 200 mg/L; M-COD, 1200 mg/L; H-COD, 4200 mg/L. The results indicated that the COD exerts a negligible effect on the nitrogen removal ability within the first 24 h. However, the nitrification rate decreased with culture time; the ammonium degradation rates were found to be 80.26%, 57.56%, and 43.43% at 72 h in the three COD groups, respectively. These values correspond to decreases of 19.40%, 41.83%, and 51.48%, respectively, in relation to those observed at 24 h. The activated sludge in the different COD groups exhibited similar community compositions after 24 h, as assessed by Illumina high-throughput sequencing, while a significant difference in the relative abundances of some organisms occurred after 48 and 72 h. Proteobacteria was the main phylum, with a relative abundance of >51.45%. The genera Aridibacter, Paracoccus, Nitrospira, and Nitrosomonas were suppressed by COD load over time. This study may contribute to our knowledge about the nitrification ability and microbial communities in activated sludge at different COD load levels.

Comparison of planktonic bacterial communities indoor and outdoor of aquaculture greenhouses

“…Meron et al (2011) examined changes in bacterial communities in the coral mucus, tissue and skeleton following exposure of the coral Acropora eurystoma to two different pH conditions: 7.3 and 8.2 (ambient seawater) and found that the microbial community was different at the two pH values and an increase in bacteria associated with diseased and stressed corals in the corals maintained at the lower pH. The activated sludge in the different chemical oxygen demand groups exhibited similar community compositions after 24 h, while a significant difference in the relative abundances of some organisms occurred after 48 and 72 h (Li et al, 2020). COD Mn , Chla and Total-N were the most appropriate parameters to describe the environmental interpretation of bacterial ordinations and COD Mn was the predominant factor (Fan et al, 2020).…”

Construction of Nitrification Model With Nitrifying Coal Ash in Aerobic Treatment of High Strength Wastewater

“…And the gap between them gradually narrowed to 5.09 mg N/(L•h) from 13.39 mg N/(L•h). Exist of organic in influent not only act as a disincentive to nitrification of nitrifiers but also change the microbial community structure in system (Li et al, 2020). Both of them weaken the NH 4 + -N removal rates of experiment.…”

Assessment of Chemical Oxygen Demand Removal Efficiency and Microbial Dynamics during Aerobically Degradation of Wastewater in Activated Sludge

“…Inclusively, the declining COD removal kinetics coupled with temporal changes in operational parameters and microbial community structure underscores the importance of stability for optimizing activated sludge performance. A balanced mixed community with high functional redundancy appears critical to maintain treatment resilience and consistency longterm performance of treatment (Li et al, 2020). The present exertion of study as shown in Table 4 employed an activated sludge system with controlled operational parameters of MLSS, SVI, and F/M ratio to achieve 78.57% COD removal during early-stage treatment of synthetic wastewater.…”