Thiobacillus, Comamonas, Azoarcus,
Thauera, and Gp4 were the main genera widespread in most sludge
samples whereas autotrophic nitrifiers, such as AOB and NOB
unexpectedly existed as the minor species. The operation mode,
flow rate and temperature of CWWTPs should be the key factors
in shaping the community, and the microbial community from
A/O/O mode was distinctly different from others. The profound
understanding of CWWTP microbial communities in this study will
be helpful in developing efficient strategies for coking wastewater
treatment.