Characteristics of Biological Nitrogen Removal in a Multiple Anoxic and Aerobic Biological Nutrient Removal Process.

Huoqing Wang,Yuntao Guan,Li Li,Guangxue Wu

doi:10.1155/2015/531015

Huoqing Wang, Yuntao Guan + Show 2 more

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https://doi.org/10.1155/2015/531015

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Abstract

Two sequencing batch reactors, one with the conventional anoxic and aerobic (AO) process and the other with the multiple AO process, were operated to examine characteristics of biological nitrogen removal, especially of the multiple AO process. The long-term operation showed that the total nitrogen removal percentage of the multiple AO reactor was 38.7% higher than that of the AO reactor. In the multiple AO reactor, at the initial SBR cycle stage, due to the occurrence of simultaneous nitrification and denitrification, no nitrite and/or nitrate were accumulated. In the multiple AO reactor, activities of nitrite oxidizing bacteria were inhibited due to the multiple AO operating mode applied, resulting in the partial nitrification. Denitrifiers in the multiple AO reactor mainly utilized internal organic carbon for denitrification, and their activities were lower than those of denitrifiers in the AO reactor utilizing external organic carbon.

Highlights

Nitrogen and phosphorus in discharged wastewater can be key inducers for the eutrophication of receiving water bodies
In the multiple AO technology, by adopting the multiple alternative AO process, simultaneous nitrification and denitrification could be enhanced and complete nitrification would occur in the final aerobic phase
The multiple AO reactor shortened the aerobic phase by 33.3% compared with the AO reactor

Summary

Introduction

Nitrogen and phosphorus in discharged wastewater can be key inducers for the eutrophication of receiving water bodies. It is necessary to develop new or optimize the existing wastewater treatment technologies for compliance with the latest discharge standards. Biological nitrogen removal is achieved by sequential nitrification under aerobic conditions and denitrification under anoxic conditions. Predenitrification is widely applied for biological nitrogen removal, where denitrification occurs firstly in the anoxic phase by recycling nitrified wastewater from the following aerobic phase. In this type of anoxic and aerobic (AO)

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