an airlift-type activated sludge reactor using a sponge support medium was fed with wastewater containing 500 mg-n/l of nh4 +-n. in order to establish partial nitrification, the reactor was kept at 35°c. moreover, the reactor was started up with the nahco3 solution as an alkali agent to supply inorganic carbon for enhancement of partial nitrification. the partial nitrification was established d...

Novel nitrogen removal technologies via nitrite pathway attract increasing interest in recent years. In this study, batch experiments were performed to investigate nitrite accumulation characteristics and shifts in nitrifying community structure at different growth environments including ammonia concentration, pH and alkalinity. It was found that nitrite accumulation ratios were maintained at a...

Effects of external carbon sources and COD/NO(3)-N on nitrite accumulation through denitrification were studied at a temperature of 28±2.0 °C using mixed activated sludge. Nitrite accumulation was observed for each type of carbon source studied. Glucose resulted in the greatest nitrite accumulation and production rate, which were 14.51±2.41 mg/L and 0.121±0.013 g N/(g VSS d), respectively. More...

Although nitrite effect on enhanced biological phosphorus removal (EBPR) has been previously studied, very limited research has been undertaken about the effect of nitrite accumulation caused by nitritation on EBPR. This paper focused on nitrite effect from nitritation on EBPR in a sequencing batch reactor treating domestic wastewater. Results showed that nitrite of below 10mg/L did not inhibit...

OBJECTIVE The purpose of this study was to investigate the effects of vesnarinone on nitric oxide (NO) synthesis in cardiac myocytes. METHODS We measured the accumulation of nitrite, a stable oxidation product of NO synthase (iNOS) protein in cultured neonatal rat cardiac myocytes. RESULTS Incubation of the cultures with interleukin-1 beta (IL-1 beta; 10 ng/ml) and tumor necrosis factor alp...

Nitrite and nitrate restore deficient endogenous nitric oxide (NO) production as they are converted back to NO, and therefore complement the classic enzymatic NO synthesis. Circulating nitrate and nitrite must cross membrane barriers to produce their effects and increased nitrate concentrations may attenuate the nitrite influx into cells, decreasing NO generation from nitrite. Moreover, xanthin...

agricultural advancement and population growth have prompted increases in food supplies, and higher crop yields have been made possible through the application of fertilizers. large quantities of livestock and poultry on farms, along with the accumulation of biomass and agricultural residues, can cause contamination of ground water resources and other water sanitation concerns in both developin...

BACKGROUND Elevated plasma homocysteine levels have been reported to be an independent risk factor for vascular disease. However, there have been no reports concerning the effects of homocysteine on the production of nitric oxide (NO), another modulator of vascular function and proliferation, by the vascular smooth muscle. METHODS AND RESULTS We investigated the effects of homocysteine on NO ...