Ammonium removal from groundwater using a zeolite permeable reactive barrier: a pilot-scale demonstration.
In situ remediation of ammonium-contaminated groundwater is possible through a zeolite permeable reactive barrier (PRB); however, zeolite's finite sorption capacity limits the long-term field application of PRBs. In this paper, a pilot-scale PRB was designed to achieve sustainable use of zeolite in removing ammonium (NH(4)(+)-N) through sequential nitrification, adsorption, and denitrification. An oxygen-releasing compound was added to ensure aerobic conditions in the upper layers of the PRB where NH(4)(+)-N was microbially oxidized to nitrate. Any remaining NH(4)(+)-N was removed abiotically in the zeolite layer. Under lower redox conditions, nitrate formed during nitrification was removed by denitrifying bacteria colonizing the zeolite. During the long-term operation (328 days), more than 90% of NH(4)(+)-N was consistently removed, and approximately 40% of the influent NH(4)(+)-N was oxidized to nitrate. As much as 60% of the nitrate formed in the PRB was reduced in the zeolite layer after 300 days of operation. Removal of NH(4)(+)-N from groundwater using a zeolite PRB through bacterial nitrification and abiotic adsorption is a promising approach. The zeolite PRB has the advantage of achieving sustainable use of zeolite and immediate NH(4)(+)-N removal.
School of Water Resources and Environment, and Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China E-mail: feiliu@cugb.edu.cn.
Shengpin
S
Li
China Meat Research Center, Beijing Academy of Food Sciences, Beijing 100068, China.
Guoxin
G
Huang
Institute of Hydrogeology & Environmental Geology, CAGS, Shijiazhuang 050061, China.
Xiangke
X
Kong
School of Water Resources and Environment, and Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China E-mail: feiliu@cugb.edu.cn.
Yingzhao
Y
Yang
School of Water Resources and Environment, and Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China E-mail: feiliu@cugb.edu.cn.
Fei
F
Liu
School of Water Resources and Environment, and Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China E-mail: feiliu@cugb.edu.cn.
Guohua
G
Hou
School of Water Resources and Environment, and Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China E-mail: feiliu@cugb.edu.cn.
Honghan
H
Chen
D000327:Adsorption; D064751:Ammonium Compounds / Q000378:metabolism*; D060587:Groundwater / Q000032:analysis*; D009566:Nitrates / Q000378:metabolism*; D010084:Oxidation-Reduction; D010865:Pilot Projects; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D017641:Zeolites / Q000378:metabolism*
D064751:Ammonium Compounds; D009566:Nitrates; D014874:Water Pollutants, Chemical; D017641:Zeolites