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Removal of Organic Matter and Nitrogen from River Water in a Model Floodplain
Author(s) -
Chung JongBae,
Kim SeungHyun,
Jeong ByeongRyong,
Lee YoungDeuk
Publication year - 2004
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2004.1017
Subject(s) - organic matter , environmental chemistry , denitrification , chemistry , environmental science , chemical oxygen demand , floodplain , water quality , nitrogen , environmental engineering , wastewater , ecology , organic chemistry , biology
A significant improvement in river water quality cannot be expected unless nonpoint‐source contaminants are treated in addition to the further treatment of point‐source contaminants. If river water is sprayed over a floodplain, the consequent water filtration through the sediment profile can simultaneously remove organic matter and nitrogen in the water through aerobic and denitrifying reactions. This hypothesis was tested using lysimeters constructed from polyvinyl chloride (PVC) pipe (150 cm long, 15 cm in diameter) packed with loamy sand floodplain sediment. Water was applied to the top of the lysimeters at three different flow rates (48, 54, and 68 mm d −1 ). Concentrations of NO 3 and dissolved oxygen (DO), chemical oxygen demand (COD), and redox potential (Eh) in the water were measured as functions of depth after the system reached steady states for both water flow and reactions. At the rate of 68.0 mm d −1 , a reducing condition for denitrification developed below the 5‐cm depth due to the depletion of O 2 by organic matter degradation in the surface oxidizing layer; Eh and DO were below 205 mV and 0.4 mg L −1 , respectively. At a depth of 70 cm, COD and NO 3 –N concentration decreased to 5.2 and 3.8 mg L −1 from the respective influent concentrations of 17.1 and 6.2 mg L −1 Most biodegradable organic matter was removed during flow and further removal of NO 3 was limited by the lack of an electron donor (i.e., organic matter). These results indicate that the floodplain filtration technique has great promise for treatment of contaminated river water.