The Effect of Corrosion Inhibitor on Corrosion Control
of Copper Pipe and Green Water Problem

Lee, Ji Eun; Lee, Hyun Dong; Kim, Gi Eun

doi:2012.17.1.17

Environmental Engineering Research 2012;17(1): 17-25. DOI: https://doi.org/10.4491/eer.2012.17.1.017

The Effect of Corrosion Inhibitor on Corrosion Control of Copper Pipe and Green Water Problem

Ji Eun Lee¹, Hyun Dong Lee^2,3^†, and Gi Eun Kim^2,3

¹School of Chemical and Biomolecular Engineering, University of Sydney, NSW 2006, Australia.
²Department of Construction & Environment Engineering, University of Science & Technology, Daejeon 305-350, Korea
³Environmental Engineering Research Division, Korea Institute of Construction Technology, Goyang 411-712, Korea

Corresponding Author: Hyun Dong Lee ,Tel: +82-31-910-0297, Fax: +82-31-910-0291, Email: hdlee@kict.re.kr/korean

Received: September 7, 2011; Accepted: February 15, 2012.

ABSTRACT

Concern about green water problem has surfaced as a serious issue in Korea. In order to solve this problem, it is necessary to research inhibition of green water and corrosion control of copper pipe in water service. This paper discovered that moderate corrosion inhibitors can solve the green water problem and copper corrosion in water service by adding the optimal concentration of corrosion inhibitors based on regulation. Firstly, in the case of phosphate based corrosion inhibitors, as dosage of the corrosion inhibitor increases from 1 mg/L to 5 mg/L, the relative effect of corrosion inhibitor declines rapidly. Secondly, except for 1 mg/L dosage of silicate based inhibitor, relative effects of the inhibitor displays a positive number depending on inhibitor concentration. The most significant result is that the amount of copper release shows a downward trend, whereas the phosphate based inhibitor accelerates copper ion release as the inhibitor dosage increases. Thirdly, as the dosage of mixed inhibitors increases to 10 mg/L, the copper release change shows a similar trend of phosphate based inhibitor. Lastly, according to the Langelier saturation index (LI), silicate based inhibitors have the most non corrosive value. Larson ratio (LR) indicates that phosphate based inhibitors are the least corrosive. Korea water index (KWI) represents that silicate based inhibitors are most effective in controlling copper pipe corrosion.