学会誌「EICA」

[研究発表] ORP control for nitrogen removal from sewage with low C/N ratio in a hybrid biofilm pilot plant

内容

[研究発表] ORP control for nitrogen removal from sewage with low C/N ratio in a hybrid biofilm pilot plant

巻

9巻2号2004年

Page

75

題名

ORP control for nitrogen removal from sewage with low C/N ratio in a hybrid biofilm pilot plant

Title

ORP control for nitrogen removal from sewage with low C/N ratio in a hybrid biofilm pilot plant

著者

Y. O. Kim*，H. U. Nam*，I. G. Byun**，T. J. Park** and T. H. Lee*

Authors

Y. O. Kim*，H. U. Nam*，I. G. Byun**，T. J. Park** and T. H. Lee*

著者表記

Author attribution

著者勤務先名

Office name

著者所属名

キーワード

Key Words

Denitrification; external carbon source; low C/N ratio; nitrogen removal; ORP control

概要

Abstract

An oxidation reduction potential (ORP) control system, which adjusted amount of external carbon source for denitrification based on ORP values, was applied to a hybrid biofilm pilot plant for cost-effective removal of nitrogen from sewage with low C/N ratio. The pilot plant consisted of serially anoxic-, aerobic-, anoxic-, aerobic-reactor and both aerobic reactors were separated two parts with a baffle. Influent BOD and total nitrogen (T-N) concentrations were varied in the rage of 25.0-140.5 mg/L and 15.5-46.5 mg/L, respectively. Because the C/N ratio (1.6-3.0) of the influent was too low to complete denitrification, an external carbon source of methanol was added to the second anoxic reactor to meet the regulation limit of effluent T-N, 10.0 mg/L. The effluent T-N concentration was directly affected by methanol addition in the tested concentration range, 50 to 100 mg/L as final concentration in the second anoxic reactor. An empirical equation decided from the ORP values according to added methanol amount was ORP = 0.0055[methanol]2 - 2.2733[methanol] + 37.402. The concentration of methanol addition was decided from an empirical equation according to the ORP value measured in the second anoxic reactor. As a result of applying the ORP automatic control system, 20% of the amount of methanol addition was reduced comparing with the fixed amount addition of methanol as final concentration as 75 mg/L without ORP control system. These results suggested that ORP auto-control system would be applied to efficient and cost effective removal of nitrogen from sewage with low C/N ratio.