Cold Climate Feasibility of Constructed Wetlands for Wastewater TreatmentEPA Grant Number: U915165
Title: Cold Climate Feasibility of Constructed Wetlands for Wastewater Treatment
Investigators: Biederman, Joel A.
Institution: Montana State University - Bozeman
EPA Project Officer: Lee, Sonja
Project Period: January 1, 1997 through January 1, 1999
Project Amount: $68,000
RFA: STAR Graduate Fellowships (1997) RFA Text | Recipients Lists
Research Category: Fellowship - Environmental Engineering , Academic Fellowships , Engineering and Environmental Chemistry
The main objective of this research project is to quantify and model the effects of a cold climate, such as that found in Montana, on the performance of constructed wetlands for the treatment of water pollutants associated with rural environments. The specific objectives of this research project are to: (1) provide additional information on the feasibility of using subsurface flow (SF) wetlands to treat wastewater in cold climates; (2) develop objective design and operational criteria for constructed SF wetlands based on evaluation and modeling of key process controls; and (3) document the quality of water emerging from model SF wetlands.
Bench-scale wetlands have been constructed and placed in a climatically controlled greenhouse environment subject to natural light conditions. Two experimental systems were designed to compare batch operation with plug flow. A warm temperature was maintained for 1 year to facilitate system establishment, and allow start-up characterization. Native wetland plants (cattail, bulrush, and sedge) are being tested for their influence on treatment mechanisms and efficiency. A synthetic wastewater source is fed to the wetlands with inflow and outflow concentrations of several important parameters monitored, including chemical oxygen demand, total organic carbon nitrogen species, phosphate, total phosphorus, and sulfate. Ambient temperature is regulated between 4°C and 24°C in increments of 4°C with steps lasting approximately 1 month at each temperature. No artificial light is applied, and the temperature regulation schedule approximately corresponds to the actual season and day length (i.e., coldest temperature during the shortest photoperiod).