论文信息 - A hypothesis for the cause of low F/M filament bulking in nutrient removal activated sludge systems

A hypothesis for the cause of low F/M filament bulking in nutrient removal activated sludge systems

Abstract Laboratory research has indicated that a possible cause of low F/M filament bulking in ND (nitrification-denitrification) and NDBEPR (nitrification-denitrification biological excess phosphorus removal) systems occurs as a result of competition for substrate between filamentous and floc-forming organisms which have different denitrification pathways. In ND and NDBEPR systems alternating anoxic-aerobic conditions prevail and continuous utilization of particulate slowly biodegradable COD (SBCOD) by floc-forming organisms in these systems leads to accumulation of the denitrification intermediates nitrite (NO2−) and nitric oxide (NO) under anoxic conditions. It is proposed that a cause for low F/M filament bulking is that the intermediate NO inhibits the utilization of SBCOD by floc-formers under subsequent aerobic conditions, with high concentrations of NO2− exacerbating this effect, thereby allowing filamentous organisms, which do not accumulate NO, to dominate. Some experimental evidence to support this proposal is presented.

[1] D. Jenkins,et al. The Selector Effect on Filamentous Bulking in Long Sludge Age Activated Sludge Systems , 1991 .

[2] S. Ferguson,et al. Nitric oxide formed by nitrite reductase of Paracoccus denitrificans is sufficiently stable to inhibit cytochrome oxidase activity and is reduced by its reductase under aerobic conditions. , 1990, Biochimica et biophysica acta.

[3] W. Payne. Reduction of nitrogenous oxides by microorganisms. , 1973, Bacteriological reviews.

[4] M. Showe,et al. Localization and Regulation of Synthesis of Nitrate Reductase in Escherichia coli , 1968, Journal of bacteriology.

[5] F. Pichinoty,et al. Influence des conditions de culture sur la formation de la nitrate-réductase d'Aerobacter aerogenes , 1961 .

[6] V. Dadák,et al. Aerobic dissimilatory reduction of nitrite by cells of Paracoccus denitrificans: the role of nitric oxide , 1987 .

[7] R. Veeningen,et al. The synthesis of the dissimilatory nitrate reductase under aerobic conditions in a number of denitrifying bacteria, isolated from activated sludge and drinking water , 1977 .

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

[9] J. Krul. Dissimilatory nitrate and nitrite reduction under aerobic conditions by an aerobically and anaerobically grown Alcaligenes sp. and by activated sludge. , 1976, The Journal of applied bacteriology.