(Montana State University - Bozeman, College of Engineering, 2007) Schultz, Rickey Lynn, Jr.; Chairperson, Graduate Committee: Otto Stein; Paul Hook (co-chair)
Constructed wetlands (CW) are a viable alternative wastewater treatment technology for many wastewater types. However, recommended loading rates vary widely between regulatory agencies. A greenhouse experiment was carried out for approximately 19 months to study the effect of loading rate, plant species selection, temperature and season on pollutant removal in bench-scale constructed wetlands. The wetlands were operated in batch mode at batch lengths of 3, 6, and 9 days, corresponding to loading rates of 210, 105, and 70 kg COD/ha·d, respectively. Greenhouse temperature cycled from 4°C to 24°C. Treatments included plant species Carex utriculata, Schoenoplectus acutus and Typha latifolia and unplanted controls. Water and air temperature, redox potential, COD, SO4 2-, NH4 +, PO4 3- and pore volume were monitored throughout the study. Data from the current research is compared with a previous study performed under similar conditions, but with a 20 day batch length resulting in a loading rate of 32 kg COD/ha·d. Performance of all treatments and loading rates was compared on the basis of percent COD and SO4 2- removal, redox potential, and remaining NH4 + and PO4 3- concentration.
