A new step aeration approach towards the improvement of nitrogen removal in a full scale Carrousel oxidation ditch

In order to optimize the flow field in a full-scale Carrousel oxidation ditch with many sets of disc aerators operating simultaneously, an experimentally validated numerical tool, based on computational fluid dynamics (CFD), was proposed. A full-scale, closed-loop bioreactor (Carrousel oxidation ditch) in Ping Dingshan Sewage Treatment Plant in Ping Dingshan City, a medium-sized city in Henan Province of China, was evaluated using CFD. Moving wall model was created to simulate many sets of disc aerators which created fluid motion in the ditch. The simulated results were acceptable compared with the experimental data and the following results were obtained: (1) a new method called moving wall model could simulate the flow field in Carrousel oxidation ditch with many sets of disc aerators operating simultaneously. The whole number of cells of grids decreased significantly, thus the calculation amount decreased, and (2) CFD modeling generally characterized the flow pattern in the full-scale tank. 3D simulation could be a good supplement for improving the hydrodynamic performance in oxidation ditch designs.

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Nitrogen removal performance and bacterial community in a full-scale modified Orbal oxidation ditch with internal nitrate recycle and biocarriers

Journal of Water Process Engineering ◽

10.1016/j.jwpe.2020.101791 ◽

2020 ◽

pp. 101791

Author(s):

Xianbao Wang ◽

Chuyue Gao ◽

Pengkang Jin ◽

Yudi Zhang ◽

Yili Xie ◽

...

Keyword(s):

Bacterial Community ◽

Nitrogen Removal ◽

Full Scale ◽

Oxidation Ditch ◽

Orbal Oxidation Ditch

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Variation of biological and hydrological parameters and nitrogen removal optimization of modified Carrousel oxidation ditch process

Journal of Central South University ◽

10.1007/s11771-012-1081-7 ◽

2012 ◽

Vol 19 (3) ◽

pp. 842-849

Author(s):

Zhi Zhang ◽

Bo-lin Li ◽

Xin-yi Xiang ◽

Chi Zhang ◽

Hua Chai

Keyword(s):

Nitrogen Removal ◽

Oxidation Ditch ◽

Hydrological Parameters ◽

Carrousel Oxidation Ditch

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Enhancing nitrogen removal in an Orbal oxidation ditch by optimization of oxygen supply: practice in a full-scale municipal wastewater treatment plant

Bioprocess and Biosystems Engineering ◽

10.1007/s00449-012-0694-4 ◽

2012 ◽

Vol 35 (7) ◽

pp. 1097-1105 ◽

Cited By ~ 14

Author(s):

Xin Zhou ◽

Xuesong Guo ◽

Yunping Han ◽

Junxin Liu ◽

Jincheng Ren ◽

...

Keyword(s):

Wastewater Treatment ◽

Nitrogen Removal ◽

Wastewater Treatment Plant ◽

Oxygen Supply ◽

Municipal Wastewater ◽

Treatment Plant ◽

Full Scale ◽

Municipal Wastewater Treatment ◽

Oxidation Ditch ◽

Orbal Oxidation Ditch

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Nitrogen Removal in an Oxidation Ditch with Intermittent Aeration

Water Science & Technology ◽

10.2166/wst.1987.0202 ◽

1987 ◽

Vol 19 (1-2) ◽

pp. 209-218 ◽

Cited By ~ 4

Author(s):

Katsuto Inomae ◽

Hiroyuki Araki ◽

Kenichi Koga ◽

Youichi Awaya ◽

Tetsuya Kusuda ◽

...

Keyword(s):

Nitrogen Removal ◽

Carbon Sources ◽

Full Scale ◽

Operating Conditions ◽

High Rate ◽

Oxidation Ditch ◽

Intermittent Aeration ◽

Plant System ◽

Anoxic Zones ◽

Typical Process

The typical process of nitrogen removal in the oxidation ditch is achieved through the control of oxygen supply ( forming aerobic and anoxic zones within the ditch channel) or alternating aeration using intermittently operating aerator(s). The operating conditions for efficient nitrogen removal with any of these methods have yet to be clarified. The purpose of this study is to establish an oxidation ditch system with a high rate of nitrogen removal by intermittent aeration. Effects of intermittent aeration on nitrogen removal characteristics were studied by experiments with a bench scale- and full scale-plant and by simulation. The conditions of optimum operation (aerobic and anoxic periods) for a high rate of nitrogen removal were found. These conditions principally depend upon the rates of nitrification and denitrification. By operating the full scale plant system with intermittent aeration ( cycle time is 45 minutes and aerobic ratio is 0.42 ), a high rate nitrogen removal efficiency of 81% was achieved without adding any alkaline matter or organic carbon sources. It was shown that the results of simulation agree with the observed data of the full scale plant system, and that the rate of denitrification depends upon the conditions of intermittent aeration.

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