Evaluation of Free-water-surface Constructed Wetlands for the Treatment of Poultry Lagoon Effluent
A free-water-surface constructed wetlands system was installed at the Auburn University poultry unit in Auburn, Alabama. The wetlands system, consisting of three series of dual cell wetlands, was installed for the purpose of treating effluent from an anaerobic poultry waste lagoon. The first series (two cells) contained Sagittaria lancifolia which occupied approximately 10% of the water column. The second series contained Phragmites australis and Scirpus spp. which occupied approximately 5% of the water column. The third series was not vegetated in order to provide a research control. Samples were collected from the influent and effluent of the system during the period from August 1993 until March 1994 in order to evaluate the ability of constructed wetlands to treat poultry lagoon wastewater and the effects cold winter months have on the treatment process. To investigate and monitor groundwater impact, two lysimeters were installed in each cell of each series at depths of 0.6 m and 1.3 m. Monitored variables included COD, BOD, TKN, NH4, PO4 and K in the influent and effluent. The lysimeter samples were analyzed for the same parameters with the exception of not analyzing COD and BOD and analyzing NO3.