COMBINED TREATMENT OF NITRATE AND PHOSPHATE IN THE PRESENCE OF ZERO-VALENT IRON

Chang, Yoon-Young; Choi, Sang-Il

Environmental Engineering Research 2000;5(2): 77-83.

Yoon-Young Chang^†, and Sang-Il Choi

Department of Environmental Engineering, Kwangwoon University, Seoul 139-701, Korea

Corresponding Author: Yoon-Young Chang ,

Received: June 10, 2000; Accepted: August 6, 2000.

ABSTRACT

The characteristics of zero-valent iron (Fe°)-induced denitrification in the absence and presence of phosphate was examined under anaerobic conditions. The reductive denitrification was more extensive with acid-treated iron particles prior to addition of a pure nitrate solution. The initial rate of the reductive reaction was first-order with respect to mass of iron in the low stoichiometric excess of Fe° particles. Increasing the phosphate concentration in the reaction solution containing Fe° lowered the removal percent of nitrate, despite little effect on the initial rate of denitrification. However, the addition of nitrate slightly accelerated the disappearance of phosphate from the aqueous solution in the Fe°-water system. This may propose that the iron technology can be a useful in situ or above-ground technology for the treatment of nitrate and phosphate-contaminated water.

Keywords: iron particles | chemical reduction | nitrate | phosphate | precipitation