• Assessing the Role of Citric Acid in Denitrification of Nitrate in Slow-releasing Carbon Source Tablet

  • Kyungjin Han1·Yuhoon Yeum2·Young Kim2·Sooyoul Kwon3*

  • 1Department of Environmental Engineering, Korea National University of Transportation, Chungcheongbuk-do 27469, Korea
    2Department of Environmental Engineering, Korea University, Sejong 30019, Korea
    3Department of Environmental Health, Korea National Open University, Seoul 03087, Korea

  • 완효성 탄소원 정제 내 citric acid의 생물학적 탈질소화 영향

  • 한경진1·염여훈2·김 영2·권수열3*

  • 1한국교통대학교 환경공학과, 2고려대학교 환경시스템공학과, 3한국방송통신대학교 보건환경학과

  • This article is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study utilized citric acid as a floating agent in biological denitrification process and assessed its role under different carbon supplying conditions. Several microcosm tests including citric acid active (CAA), precipitating tablet release active (PTRA) and floating tablet release active (FTRA) were conducted to evaluate nitrate denitrification efficacy. In CAA reactors, nitrate removal was accompanied by the formation of denitrification by-products such as nitrite and nitrous oxide, with the extent of nitrate removal being proportional to citric acid concentration. These results suggest that citric acid induced heterotrophic biological denitrification. PTRA reactor that incorporated CAA and the same electron donor showed a similar denitrification efficiency to CAA reactor. FTRA reactor, which contained the same amount of fumarate as PTRA, enhanced denitrification by 7% as compared to the PTRA reactor. The overall results of this work indicate that surplus citric acid can be efficiently utilized in heterotrophic denitrification.


Keywords: Heterotrophic nitrate denitrification, Citric acid, Carbon source/Electron donor, Slow release tablet

This Article

  • 2022; 27(3): 41-49

    Published on Jun 30, 2022

  • 10.7857/JSGE.2022.27.3.041
  • Received on May 24, 2022
  • Revised on May 24, 2022
  • Accepted on Jun 21, 2022

Correspondence to

  • Sooyoul Kwon

  • Department of Environmental Health, Korea National Open University, Seoul 03087, Korea

  • E-mail: sykwon@knou.ac.kr