Res. Chem. Intermed.
, Vol. 32, No. 5–6, pp. 585–594 (2006)
Also available online - www.vsppub.com
Reduction of nitrate ion using hydrogen permeating
Pd foil electrodes
, MASASHI TANAKA
, YOSHINORI NISHIKI
, TSUNETO FURUTA
, HIROSHI INOUE
and CHIAKI IWAKURA
Research and Development Department, Permelec Electrode Ltd., 2023-15 Endo, Fujisawa-city,
Kanagawa 252-0816, Japan
Department of Applied Chemistry, College of Engineering, Osaka Prefecture University, Sakai,
Osaka 599-8531, Japan
Received 24 November 2004; accepted 25 January 2005
Abstract—The successive electrochemical reduction system using hydrogen-permeable Pd foil
electrodes with Pd black catalyst was applied to reduction of nitrate ion. It was revealed that the
second metals co-deposited to Pd black catalyst showed an excellent selectivity for decomposition of
, and was stable for at least 200 days. This system employing a compact and a simple
electrolysis cell is expected to be an alternative or a supplement to conventional biological treatments
for nitrate removal.
Keywords: Pd foil electrode; electrochemical reduction; long-term stability; nitrate removal.
Pollution of rivers or lakes by nitrate substances, discharged as industrial and
agricultural efﬂuents, puts a bigger strain on the environment every day . To solve
this problem, should be public regulations for the efﬂuent water quality, ultimately
targeting zero emission. A typical conventional treatment for these substances is
biological denitriﬁcation, requiring severe control to maintain anaerobiotic bacteria
and a huge reactor area due to the slow rate of the reaction. Therefore, a compact
and easy-operational treatment would be more proﬁtable instead of the above
Hydrogenation methods, wherein hydrogen gas and efﬂuents are supplied onto se-
lective solid catalysts, have been developed for nitrate removal. Cu-Pd or Cu-Sn al-
loy was selected as a suitable catalyst for nitrate ion reduction to nitrogen gas [2–8].
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