1. Fadi G (1999) Activated sludge biofilm wastewater treatment system. Water Res 33(1):230–238
2. Hu ZR, Wentzel MC, Ekama GA (2002) Anoxic growth of phosphate-accumulating organisms (PAOs) in biological nutrient removal activated sludge systems [J]. Water Res 36(19):4927–4937
3. Liu S, Wang BZ, Wang L et al (2006) Full scale application of combined SBF-AS process for municipal wastewater treatment in small towns and cities in China. J Harbin Inst Technol 3:51–55
4. Ma F, Ren NQ, Yang JX (2002) Microbiology experiments of pollution control [M]. Harbin Institute of Technology Press (in Chinese), Harbin
5. National Environmental Protection Agency (2002) Monitoring and analysis methods of water and wastewater [M], 4th edn. China Environmental Science Press (in Chinese), Beijing