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Ammonia Volatilization from Marsh–Pond–Marsh Constructed Wetlands Treating Swine Wastewater
Author(s) -
Poach M. E.,
Hunt P. G.,
Reddy G. B.,
Stone K. C.,
Matheny T. A.,
Johnson M. H.,
Sadler E. J.
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/jeq2004.0844
Subject(s) - volatilisation , wetland , marsh , ammonia volatilization from urea , wastewater , ammonia , environmental science , environmental chemistry , environmental engineering , hydrology (agriculture) , chemistry , ecology , geology , biology , geotechnical engineering , organic chemistry
Ammonia (NH 3 ) volatilization is an undesirable mechanism for the removal of nitrogen (N) from wastewater treatment wetlands. To minimize the potential for NH 3 volatilization, it is important to determine how wetland design affects NH 3 volatilization. The objective of this research was to determine how the presence of a pond section affects NH 3 volatilization from constructed wetlands treating wastewater from a confined swine operation. Wastewater was added at different N loads to six constructed wetlands of the marsh–pond–marsh design that were located in Greensboro, North Carolina, USA. A large enclosure was used to measure NH 3 volatilization from the marsh and pond sections of each wetland in July and August of 2001. Ammonia volatilized from marsh and pond sections at rates ranging from 5 to 102 mg NH 3 –N m −2 h −1 Pond sections exhibited a significantly greater increase in the rate of NH 3 volatilization ( p < 0.0001) than did either marsh section as N load increased. At N loads greater than 15 kg ha −1 d −1 , NH 3 volatilization accounted for 23 to 36% of the N load. Furthermore, NH 3 volatilization was the dominant (54–79%) N removal mechanism at N loads greater than 15 kg ha −1 d −1 Without the pond sections, NH 3 volatilization would have been a minor contributor (less than 12%) to the N balance of these wetlands. To minimize NH 3 volatilization, continuous marsh systems should be preferred over marsh–pond–marsh systems for the treatment of wastewater from confined animal operations.