WETLAND TREATMENT SYSTEMS FOR MUNICIPAL WASTEWATER AT A BOURBON DISTILLERY AND POTENTIAL VALUE OF INCORPORATING STILLAGE FOR WATER TREATMENT ENHANCEMENT

The use of constructed treatment wetlands, as a secondary treatment method for wastewater effluent from package treatment plants and distillery stillage has potential to be an innovative, sustainable method for improving water quality in the Central Kentucky region. However, the use of constructed wetlands to treat stillage and wastewater treatment plant effluent has been limited. Therefore, the objectives of this study were to: 1) quantify constructed wetland removal as a secondary treatment method for distillery’s wastewater; 2) explore the potential to utilize constructed treatment wetlands to remove nutrients from bourbon stillage; and 3) optimize treatment design to meet wastewater effluent discharge limits. Four free water surface flow treatment wetland mesocosm experiments were completed during the summer of 2023. Denitrifying conditions were measured along with collection of water quality grab samples over the 10-day experiments. The constructed wetlands removed nitrate-N between 50 to 99%, E. coli 99%, and phosphate-P between 61 to 99%, depending on influent and period of the growing season. Bourbon stillage was found to enhance removal of nutrients when added to the wetlands in combination with the wastewater effluent. Findings support constructed treatment wetlands as a potential mechanism for secondary treatment for distillery wastewater and bourbon stillage