Journal of Korean Society on Water Environment (한국물환경학회지)

Korean Society on Water Environment (한국물환경학회)
권호 표지

Direct Bio-regeneration of Nitrate-laden Ion-exchange Resin

질산성질소에 파과된 이온교환수지의 생물학적 직접 재생

  • Nam, Youn-Woo (Department of Environment Engineering, Daejeon University) ;
  • Bae, Byung-Uk (Department of Environment Engineering, Daejeon University)
  • Received : 2013.09.23
  • Accepted : 2013.11.07
  • Published : 2013.11.30
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Abstract

Ion-exchange technology is one of the best for removing nitrate from drinking water. However, problems related to the disposal of spent brine from regeneration of exhausted resins must be overcome so that ion exchange can be applied more widely and economically, especially in small communities. In this background, a combined bio-regeneration and ion-exchange system was operated in order to prove that nitrate-laden resins could be bio-regenerated through direct contact with denitrifying bacteria. A nitrate-selective A520E resin was successfully regenerated by denitrifying bacteria. The bio-regeneration efficiency of nitrate-laden resins increased with the amount of flow passed through the ion-exchange column. When the fully exhausted resin was bio-regenerated for 5 days at the flowrate of 30 BV/hr and MLSS concentration of $125{\pm}25mg/L$, 97.5% of ion-exchange capacity was recovered. Measurement of nitrate concentrations in the column effluents also revealed that less than 5% of nitrate was eluted from the resin during 5 days of bio-regeneration. This result indicates that the main mechanism of bio-regeneration is the direct reduction of nitrate by denitrifying bacteria on the resin.

Keywords

Acknowledgement

Supported by : 중소기업청

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