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\bibitem{Liu_etal2017} {\textquotedblleft}\textit{Optimizing sulfur-driven mixotrophic denitrification process : system performance and nitrous oxide emission}{\textquotedblright}. Liu Y, Ngo HH, Guo W, Zhou J, Peng L, Wang D, Chen X, Sun J, Ni B-J, Chemical engineering science \textbf{172}, 414 (2017).   http://doi.org/10.1016/J.CES.2017.07.005

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