Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/15/1996
Publication Date: N/A
Technical Abstract: Large concentrations of confined swine operations have caused new dimensions of environmental concern in the eastern Coastal Plain. There is interest in methodologies of swine wastewater treatment that are environmentally sustainable and economically feasible. One such method is the use of constructed wetlands for mass removal of nutrients before discharge to land treatment areas. Through the use of constructed wetlands that contain both natural wetland and agronomic plants, over 2 Mg/ha/yr of nitrogen have been removed from swine wastewater. This removal of nitrogen is far in excess of that possible with forage or row crops, but it is less than is possible if the full denitrification potential of constructed wetlands is used. Our research data show that the constructed wetlands used for swine wastewater treatment are not carbon limited, but they are nitrate limited for denitrification. We are investigating methods for the pre-wetland nitrification of ammonia in swine wastewater. Media filtration with marl gravel and overland flow are two methods that appear to have promise, and we also are exploring other technologies such as encapsulated nitrifiers for enhanced nitrification.