Start-up of a pilot-scale membrane bioreactor to treat municipal wastewater

The start-up of a pilot-scale membrane bioreactor equipped with submerged ultrafiltration membranes to treat municipal wastewater has been studied. Attention has been paid to determine membrane separation effects on biomass development in a reactor operated without inoculation. Moreover, the activated sludge model no. 1 has been applied to model biological removal processes. Filtration alone (without biodegradation) removed more than 70% of the influent total COD due to the high particulate COD fraction typically present in municipal wastewaters. Filtration action, retaining bacteria, allowed a rapid increase of the heterotrophic activity permitting to reach efficiencies in COD removal greater than 90% in one to two days. On the other hand, nitrogen removal process needs a few days (five to twenty depending on operational conditions) to develop and stabilise in the reactors because of the required development of the nitrifying biomass. Biomass development was confirmed using respirometric techniques. The activated sludge model no. 1 with minor modification was capable of simulating reasonably well the biological processes development in the MBR.

[1]  Peter A. Vanrolleghem,et al.  Respirometry in Control of the Activated Sludge Process: Principles , 1998 .

[2]  Armin Fiechter,et al.  Advances in Biochemical Engineering , 1971 .

[3]  Peter Reichert,et al.  Concepts underlying a computer program for the identification and simulation of aquatic systems , 1994 .

[4]  G. A. Ekama,et al.  Procedures for Determining Influent COD Fractions and the Maximum Specific Growth Rate of Heterotrophs in Activated Sludge Systems , 1986 .

[5]  P. Dold,et al.  Sludge volume index settleability measures : effect of solids characteristics and test parameters , 1998 .

[6]  Tatsuki Ueda,et al.  Effects of aeration on suction pressure in a submerged membrane bioreactor , 1997 .

[7]  M. Wagner,et al.  Nitrification performance and nitrifier community composition of a chemostat and a membrane-assisted bioreactor for the nitrification of sludge reject water , 2001 .

[8]  G. Daigger,et al.  Manual on the causes and control of activated sludge bulking and foaming , 1992 .

[9]  A. Huyard,et al.  Membrane Bioreactor on Domestic Wastewater Treatment Sludge Production and Modeling Approach , 1991 .

[10]  M. Kraume,et al.  Performance of a bioreactor with submerged membranes for aerobic treatment of municipal waste water. , 2002, Water research.

[11]  T Higuchi,et al.  A model for membrane bioreactor process based on the concept of formation and degradation of soluble microbial products. , 2001, Water research.

[12]  Kazuo Yamamoto,et al.  Direct Solid-Liquid Separation Using Hollow Fiber Membrane in an Activated Sludge Aeration Tank , 1989 .

[13]  Giuseppe Laera,et al.  Biomass growth and activity in a membrane bioreactor with complete sludge retention. , 2004, Water research.