Simultaneous biodegradation of nitrogen-containing aromatic compounds in a sequencing batch bioreactor.
Many nitrogen-containing aromatic compounds (NACs), such as nitrobenzene (NB), 4-nitrophenol (4-NP), aniline (AN), and 2,4-dinitrophenol (2,4-DNP), are environmentally hazardous, and their removal from contaminated water is one of the main challenges facing wastewater treatment plants. In this study, synthetic wastewater containing NB, 4-NP, 2,4-DNP, and AN at concentrations ranging from 50 to 180 mg/L was fed into a sequencing batch reactor (SBR). Analyses of the SBR system indicated that it simultaneously removed more than 99% of the NACs at loading rates of 0.36 kg NB/(m3 x d), 0.3 kg 4-NP/(m3 x d), 0.25 kg AN/(m3 x d), and 0.1 kg 2,4-DNP/(m3 x d). Bacterial groups of Bacteriodetes, Candidate division TM7, alpha-Proteobacteria, and beta-Proteobacteria were dominant in the clone libraries of 16S rRNA genes retrieved from the microbial communities in the SBR system. "Cycle tests" designed to alter feeding and aeration parameters of the SBR system demonstrated that the resident microbial biome of the SBR system responded rapidly to changing conditions. Consumption of O2 was concomitant with the apparent mineralization of NACs. Aromatic ring-cleaving dioxygenase activities suggested that (1) AN and NB were degraded via catechol 2,3-dioxygenase; (2) 4-NP was degraded via 1,2,4-benzentriol 1,2-dioxygenase; and (3) 2,4-DNP was degraded via an unresolved pathway.
Liu
Xing-Yu
XY
State Key Lab of Microbial Resources at Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, China. wellwoodliu@gmail.com
Wang
Bao-Jun
BJ
Jiang
Cheng-Ying
CY
Zhao
Ke-Xin
KX
Drake
Harold L
HL
Liu
Shuang-Jiang
SJ
D000814:Aniline Compounds / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors; D004269:DNA, Bacterial / Q000235:genetics; D049308:Dioxygenases / Q000378:metabolism; D009578:Nitrobenzenes / Q000378:metabolism*; D009584:Nitrogen; D009596:Nitrophenols / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D000814:Aniline Compounds; D004269:DNA, Bacterial; D009578:Nitrobenzenes; D009596:Nitrophenols; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; C036077:nitrobenzene; D049308:Dioxygenases; D009584:Nitrogen; C023650:aniline