Nutrients and fecal coliform removal efficiency via free water surface constructed wetland for lagoon wastewater treatment effluent.

摘要

A model free water surface-constructed wetland system was used to treat effluent of a wastewater treatment lagoon. Four replicate reactors containing four plant species were studied for 8 months. Parameters of water quality, wetland design, and plant biomass production were investigated.; Water quality parameters removal had different patterns as a function of treatment length or retention time. Pollutants were reduced to background levels beyond the first third of reactors length. The steady-state pollutant removals were 82% for total suspended solids, 80% for volatile suspended solids, 95% for ammonia, 53% for dissolved organic carbon, and 57% for total phosphorus and −58% for dissolved phosphorus.; The calculated retention time averaged 6 days which is 65% shorter than the design Retention time. Evapotranspiration rates were high with an average of 11 mm/day.; Dense vegetation canopy reduced radiation penetration to water column that may have reduced fecal coliform bacteria inactivation rate to 0.433 day −1.