ARS | Publication request: CONSTRUCTED WETLANDS, AN ALTERNATIVE WAY OF WASTEWATER TREATMENT

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 18, 2000
Publication Date: N/A

Technical Abstract: Wetlands hold properties that make them unique among major ecosystems on the earth. Constructed wetlands mimic natural wetlands and are designed to treat municipal, agricultural and industrial wastewater from point and non point sources. In areas, septic tank systems with field lines are commonly utilized to treat wastewater discharges from households or other sources. These septic systems usually fail when soil percolation rates are inadequate for field lines to work properly. A subsurface or surface flow constructed wetland can provide further treatment of the effluent in these situations with minimal cost and maintenance. The objective of this study was to investigate the water quality improvement by six residential constructed wetland systems. The constructed wetlands are located in four counties in North Alabama. Water samples were collected monthly for one year from inlet and outlet points of each cell within each system and analyzed for the following water quality parameters: biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), phosphorus (P), ammonium nitrogen (NH4-N), nitrate nitrogen (NO3-N), total Kjeldahl nitrogen (TKN), and fecal coliform bacteria (FC). All parameters analyzed were greatly reduced from influent to effluent points. The BOD5 was reduced up to 85%, while FC bacteria reduction was as high as 99% at most of the sites. There was significant reduction in TSS (88%), TKN (74%), P (80%), and NH4-N (56%) in most of the constructed wetlands. Data showed that treatment of effluent continued with variation during all four seasons.