Control of aeration time in the aniline degrading-bioreactor with the analysis of metagenomic: Aniline degradation and nitrogen metabolism

Identification of Aniline-Degrading Bacteria Using Stable Isotope Probing Technology and Prediction of Functional Genes in Aerobic Microcosms

“…In addition, the genera Zoogloea, Acinetobacter, and Roseomonas are all presented in two groups of the network plots (Figure 6). Thus, the co-occurrence of the above microbial communities confirmed that a "small world" was established in the aniline-spiked microcosm, as the previous studies suggested [30]. In addition, some bacteria only had a high proportion in the heavy fractions at 45 or 69 h. This change was considered to be a natural succession in microbial communities involved in aniline degradation over time [18].…”

“…These key genes were predicted not only in the 13 C-labeled heavy fractions of the samples but also in the corresponding components of the 12 C aniline treatments. The prediction results showed that many microorganisms are involved in the degradation of aniline and play an important role in various steps in aniline degradation [30].…”

Solving the problem of high concentration aniline inhibiting nitrogen removal: starting the SBBR with the prolonged aeration mode

“…As could be seen, the competition pressure for DO between aniline-degrading bacteria and nitrifiers could be reduced by prolonging the aeration time. 6 In our previous studies, 600 mg L −1 aniline wastewater was degraded with the SBBR under the condition of only 7 h of aeration, and the -N concentration was eventually kept at about 25 mg L −1 . 28 In brief, the mode of prolonged aeration was beneficial to the establishment of a stable nitrification system, and the nitrification bacteria played a full role.…”

“…5 It has been reported that the nitrification rate could be inhibited by 50% when the aniline concentration was even as low as 1 mg L −1 . 6 In addition, the high concentration of ammonia nitrogen (NH 4 + –N) produced by aniline degradation causes toxic effects to microorganisms, inhibiting microbial transformation and degradation of pollutants. 7 On the one hand, nitrifying bacteria have poor tolerance to aniline, and find it difficult to resist the toxic stimulation of aniline.…”

“…11 Moreover, some research indicated that the aeration time could affect the operational characteristics of aniline-degrading reactors. A shorter aeration time inhibits nitrification, resulting in accumulation of NH 4 + -N. 6 Conversely, prolonging the aeration time can not only ensure the tolerance of the system to a high concentration of aniline, but also provide more reaction time for the nitrification process lagging behind aniline degradation. 12 To summarize, a prolonged aeration mode can be used as a breakthrough for aniline degradation and simultaneous nitrogen removal, which provides a new idea for the treatment of aniline wastewater.…”