USE OF CONSTRUCTED WETLANDS TO TREAT SWINE WASTE AND ORGANIC POLLUTANTS FOR WATER QUALITY
OBJECTIVES: The objectives are to determine the removal rates of nutrients, suspended solids, BOD, and COD with low- medium- and high loading rates of swine wastewater based on N (10, 20, 30, and 40 Kg/ha) utilizing marsh-pond-marsh constructed wetlands; to investigate the plant residue mineralization, nitrification and denitrification rates in pond and marsh water-sediment systems; and to explore the possibilities of organic chemical removal in plant-water-sediment systems.
APPROACH: The management of swine waste is a major task for the state of North Carolina. Therefore, the proposed project deals with the swine waste treatment by using marsh-pond-marsh wetland system. This system not only will allow the reduction of nutrients and odor, but will recycle the wastewater. Six wetland cells (40 X 10 m) have been constructed in the past. All the probes (pH, Eh, temperature, water depth, and dissolved oxygen) will be installed and connected to a data-logger. The automatic samplers will be installed for sampling purposes. The swine waste at 10 and 30 Kg/ha/day will be applied to the wetland cells in the first year and 20 and 40 Kg/ha/day will be applied in the second year. Mineralization, nitrification, denitrification, and nutrient removal potential will be investigated in the wetland cells. A pilot scale constructed wetland cells will be developed to study the removal rates bf organic compounds that are considered as pollutants listed by the US Environmental Protection Agency.
PROGRESS: 1999/01 TO 1999/12
With the advent of large hog operations in North Carolina, the need to dispose of increasing amount of waste spills let to the contamination of surface and groundwater. Stringent water quality regulations implied by the state and federal governments have forced the hog operations to find an alternate waste treatment technologies. North Carolina A&T State University involved in treating swine wastewater through marsh-pond-marsh constructed wetland system. Four wetland cells have been used to treat wastewater amounted to 20 and 40 Kg N/ha/day. Summer months data showed that 75% and 66% total suspend solids, 50% alkalinity, 55 % and 50% COD, 65% and 50% total Kjeldhal N, 61% and 47% ammonium-N, 65% and 36% total P has been reduced in cells receiving 20 and 40 Kg N/ha/day applications, respectively. Initial denitrification enzyme assay were low as compared to "marsh only" designed wetlands. The low values were also observed for the control as well as nitrate and carbon amended treatments.
PUBLICATIONS: 1999/01 TO 1999/12
Hunt, P. G., T. A. Matheny and G. B. Reddy. 1999. Denitrification of swine wastewater in a Marsh-Pnd-Marsh Constructed wetland. American Society of Agronomy Annual Meetings. Salt Lake City, Utah, Oct. 31-Nov 4. Abstract p.
34PROJ NO: NCX-155-5-99-130-1 AGENCY: CSRS NC.X
PROJ TYPE: EVANS-ALLEN PROJ. STATUS: NEW
START: 01 OCT 1998 TERM: 30 SEP 2001 FY: 1999INVESTIGATOR: Reddy, G. B.
PERFORMING INSTITUTION:
NATURAL RESOURCES & ENV DESIGN
NORTH CAROLINA A&T STATE UNIV
GREENSBORO, NORTH CAROLINA 27411