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Updated: May 8, 2026

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
Published on: December 6, 2018
Use of low frequency and density ultrasound to stimulate partial nitrification and simultaneous nitrification and
Min Zheng1, Yan-Chen Liu1, Kang-Ning Xu1
1School of Environment, Tsinghua University, Beijing 100084, China.
Abstract:
Low frequency and density ultrasound has attracted considerable attention in enhancing wastewater treatment performance, particularly in the removal of nitrogen. In the present study, two sequencing batch reactors were operated to confirm the effects of ultrasound at the frequency of 40 kHz and density of 0.027 W/mL on partial nitrification and simultaneous nitrification and denitrification (SND). At the optimal irradiation time of 2.0 h, the obtained nitrite accumulation ratio and SND efficiency at full aerobic were 73.9% and 72.8%, respectively. Nitrite accumulation was the result of increased NH4(+)-N removal and improved ammonia oxidizing bacteria (AOB) activity with simultaneous inhibition of nitrite oxidizing bacteria (NOB) activity. Ultrasonic treatment could provide suitable conditions in temperature and pH for AOB growth, and destroy the NOB community structure. Moreover, organic matters were released and offered an additional carbon source for denitrification apart from the negative effects on sludge properties.
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