Denitrification has been long thought to be a unique characteristic of prokaryotes, but in recent years, several filamentous fungi and yeasts were found to exhibit denitrifying activities. This paper deals with the ex...Denitrification has been long thought to be a unique characteristic of prokaryotes, but in recent years, several filamentous fungi and yeasts were found to exhibit denitrifying activities. This paper deals with the examination of denitrification capabilities by mix-cultures of the fungus (Fusarium oxysporum) and the bacterium (Pseudomonas stutzeri TR2) in combination with a specific medium and using a synthetic wastewater of defined quality. The results revealed that P. stutzeri TR2 has strong and fast denitrifying capabilities under anaerobic conditions, and that co-denitrification of mix-cultures with F. oxysporum and P. stutzeri TR2 was more effective to remove nitrate under limited oxygen conditions. P. stutzeri TR2 was able to remove nitrate completely during cultivation for 12 hr in the specific medium and in mixed culture with F. oxysporum. A rapid N 2 evolution by mixed culture with F. oxysporum and P. stutzeri TR2 was observed in both mixed culture medium and synthetic wastewater. Using synthetic wastewater with a defined composition, about 87% of the nitrate was eliminated to form about 420μmol of N 2 from 1.0mmol of NO-3 by co-denitrification of F. oxysporum and P. stutzeri TR2 after incubation for 6days. In co-cultures of F. oxysporum and P. stutzeri TR2, N2O produced by F. oxysporum was rapidly consumed by P. stutzeri TR2. This indicated that mixed culture of F. oxysporum and P. stutzeri TR2 can be used to remove nitrate and nitrite from wastewater effectively.展开更多
Prolonged sludge age sequencing batch biofilm reactor (SBBR) without sludge discharge appears high performance phosphorus removal in treating saline and high-phosphorus wastewater,which cannot be explained by traditio...Prolonged sludge age sequencing batch biofilm reactor (SBBR) without sludge discharge appears high performance phosphorus removal in treating saline and high-phosphorus wastewater,which cannot be explained by traditional biological dephosphorization theory. The new path and mechanism of phosphorus removal was discussed on the phosphorus balance of phosphorus removal system without sludge discharge. Phosphorus balance in sludge was studied on 26 running cycles of the phosphorus reduction system. The results show that there is only 0.12 mg/g poly-P in sludge at the end of each reaction period,not phosphorus uptake by polyphosphate-accumulating organisms (PAOs). It is found that 41.8 mg/L of external phosphorus gets lost per day averagely,and 155 mg of internal phosphorus in sludge gets lost. The matrix bound phosphine in sludge achieves 36.04 mg/kg measured by alkaline digestion,and there is 18.44 mg/kg in +1 valence state,a intermediate,in sludge. This implies that the phosphorus removal system of prolonged sludge age SBBR without sludge discharge is a phosphate reduction,and the path of dephosphorization is phosphate→hypophosphite→phosphine.展开更多
The paper compared the effects of application of farm manure with chemical fertilizers on nitrification and denitrification in black soil, the result showed that the numbers of nitrobacterias and denitrobacterias in f...The paper compared the effects of application of farm manure with chemical fertilizers on nitrification and denitrification in black soil, the result showed that the numbers of nitrobacterias and denitrobacterias in farm manure treatment were both higher than that of other treatments. The intensity of denitrification in chemical treatment was higher than that of manure treatment. The content of organic matter in soil was correlated with the intensity of nitrification and denitrification, and the coefficients were respectively 0.9981 and 0.8693.展开更多
基金National Natural Science Foundation of China No.30170011 and the Programfor Promotion of Basic Research Activities for Innovative Biosciences of Japan.
文摘Denitrification has been long thought to be a unique characteristic of prokaryotes, but in recent years, several filamentous fungi and yeasts were found to exhibit denitrifying activities. This paper deals with the examination of denitrification capabilities by mix-cultures of the fungus (Fusarium oxysporum) and the bacterium (Pseudomonas stutzeri TR2) in combination with a specific medium and using a synthetic wastewater of defined quality. The results revealed that P. stutzeri TR2 has strong and fast denitrifying capabilities under anaerobic conditions, and that co-denitrification of mix-cultures with F. oxysporum and P. stutzeri TR2 was more effective to remove nitrate under limited oxygen conditions. P. stutzeri TR2 was able to remove nitrate completely during cultivation for 12 hr in the specific medium and in mixed culture with F. oxysporum. A rapid N 2 evolution by mixed culture with F. oxysporum and P. stutzeri TR2 was observed in both mixed culture medium and synthetic wastewater. Using synthetic wastewater with a defined composition, about 87% of the nitrate was eliminated to form about 420μmol of N 2 from 1.0mmol of NO-3 by co-denitrification of F. oxysporum and P. stutzeri TR2 after incubation for 6days. In co-cultures of F. oxysporum and P. stutzeri TR2, N2O produced by F. oxysporum was rapidly consumed by P. stutzeri TR2. This indicated that mixed culture of F. oxysporum and P. stutzeri TR2 can be used to remove nitrate and nitrite from wastewater effectively.
基金Project (2008ZX07315-004) supported by National Water Pollution Controlled and Treatment Great Special of China
文摘Prolonged sludge age sequencing batch biofilm reactor (SBBR) without sludge discharge appears high performance phosphorus removal in treating saline and high-phosphorus wastewater,which cannot be explained by traditional biological dephosphorization theory. The new path and mechanism of phosphorus removal was discussed on the phosphorus balance of phosphorus removal system without sludge discharge. Phosphorus balance in sludge was studied on 26 running cycles of the phosphorus reduction system. The results show that there is only 0.12 mg/g poly-P in sludge at the end of each reaction period,not phosphorus uptake by polyphosphate-accumulating organisms (PAOs). It is found that 41.8 mg/L of external phosphorus gets lost per day averagely,and 155 mg of internal phosphorus in sludge gets lost. The matrix bound phosphine in sludge achieves 36.04 mg/kg measured by alkaline digestion,and there is 18.44 mg/kg in +1 valence state,a intermediate,in sludge. This implies that the phosphorus removal system of prolonged sludge age SBBR without sludge discharge is a phosphate reduction,and the path of dephosphorization is phosphate→hypophosphite→phosphine.
文摘The paper compared the effects of application of farm manure with chemical fertilizers on nitrification and denitrification in black soil, the result showed that the numbers of nitrobacterias and denitrobacterias in farm manure treatment were both higher than that of other treatments. The intensity of denitrification in chemical treatment was higher than that of manure treatment. The content of organic matter in soil was correlated with the intensity of nitrification and denitrification, and the coefficients were respectively 0.9981 and 0.8693.
