Recovery of Ammonium Salt from Nitrate-Containing
Water by Iron Nanoparticles and Membrane Contactor |
Yuhoon Hwang1†, Dogun Kim2, Yong-Tae Ahn3, Chung-Man Moon4, and Hang-Sik Shin1 |
1Department of Civil and Environmental Engineering, KAIST, Daejeon 305-701, Korea 2Department of Civil Engineering, Kyung Hee University Global Campus, Yongin 446-701, Korea 3Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA 16802, USA 4Department of Civil and Environmental Engineering, University of Windsor, Windsor, ON, Canada |
Corresponding Author:
Yuhoon Hwang ,Tel: +82-42-350-5653, Fax: +82-42-350-3610, Email: crista@kaist.ac.kr |
Received: January 12, 2012; Accepted: May 22, 2012. |
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ABSTRACT |
This study investigates the complete removal of nitrate and the recovery of valuable ammonium salt by the combination of nanoscale
zero-valent iron (NZVI) and a membrane contactor system. The NZVI used for the experiments was prepared by chemical
reduction without a stabilizing agent. The main end-product of nitrate reduction by NZVI was ammonia, and the solution pH was stably
maintained around 10.5. Effective removal of ammonia was possible with the polytetrafluoroethylene membrane contactor system in
all tested conditions. Among the various operation parameters including influent pH, concentration, temperature, and contact time,
contact time and solution pH showed significant effects on the ammonia removal mechanism. Also, the osmotic distillation phenomena
that deteriorate the mass transfer efficiency could be minimized by pre-heating the influent wastewater. The ammonia removal rate
could be maximized by optimizing operation conditions and changing the membrane configuration. The combination of NZVI and the
membrane contactor system could be a solution for nitrate removal and the recovery of valuable products. |
Keywords:
Ammonia removal | Membrane contactor | Nano zero-valent iron | Nitrate reduction Polytetrafluoroethylene membrane |
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