TY - Front. Environ. Sci. Eng. A1 - ZHANG Peng, ZHOU Qi T1 - Simultaneous nitrification and denitrification in activated sludge system under low oxygen concentration Y1 - 2007-03-05 JF - Frontiers of Environmental Science & Engineering JO - Front. Environ. Sci. Eng. SP - 49 EP - 52 VL - 1 IS - 1 UR - https://journal.hep.com.cn/fese N1 - 10.1007/s11783-007-0009-1 ER -