Effect of External Carbon Source and Bed Turnover Rate on Denitrificaion

Jihee Song, Younghee Kim, Namjong Yoo

R&D Department Ilshin Environmental Engineering Co., Ltd..
R&D Department Ilshin Environmental Engineering Co., Ltd. Seoul, Korea.

DOI: 10.4236/ce.2012.37B004                

Abstract

This study investigated the effect of external carbon source and bed turnover rate on biological denitrification in the pilot-scale IPNR (Ilshin Phosphorus and Nitrate Removal) process. IPNR process is an up-flow reactor filled with Si-media which removes phosphorus physically and nitrate nitrogen biologically using secondary effluent from sewage treatment plant. Phosphorus (PO₄-P) was removed using HFO (Hydrous ferric oxide) by adsorption as well as nitrate nitrogen (NO₃-N) was transformed to nitrogen gas (N₂) by denitrifying bacteria using external carbon source in the same reactor. Methanol was used as an external carbon source for denitrification with various dosing concentration and Si-media bed turnover rate was varied from 6.4 ~ 7.75 day^-1. The concentrations of PO₄-P and NO₃-N in the secondary effluent were from 0.1 to 1.75 mg/L and from 1.1 to 31.9 mg/L, respectively. The results demonstrated that high amount of NO₃-N removed from 31.9 to 1.2 mg/L, at the same time PO₄-P removed from 1.75 to 0.41mg/L using secondary effluent. Denitrification was found more stable with 6.4 bed turnover/day and 130% over dosing of theoretical methanol dose for denitrification.

Keywords

Denitrification; Carbon Source; Bed Turnover Rate; Phosphorus Removal

Conflicts of Interest

The authors declare no conflicts of interest.

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