The Northwestern region of the United States (Washington, Idaho and Oregon) produces approximately 85% of the 8.6 billion pounds of the worlds' annual french fry production. Agriculture in these areas depends entirely on irrigation for crop production. Approximately 2 gallons of high strength wastewater are generated per pound of french fries. Reuse of the wastewater via land application is practiced extensively. Odor complaints, compounded by suburban sprawl into farmland, are forcing pretreatment of wastewater. Constructed wetlands are simple to operate and have proven to be cost-effective for producing odor free effluent for irrigation reuse. Wetlands are able to produce an odor free effluent, but there is some odor generated on the treatment site. This work will reduce land area required for treatment of wetlands, eliminate the on site odors, and improve the fertilizer value of the wastewater by supplementing the wastewater with alternate electron acceptors. The supplements will change the microbial ecology in the front section of the treatment wetlands and consequently inhibit production of malodorous compounds in the front section of the wetland. Addition of alternate electron acceptors will enhance the reuse value of the wastewater by eliminating odor and by addition of cationic macronutrients.
Anticipated Results/Potential Commercial Applications of Research: Success of the project will provide the potato processing industry with a novel cost-effective method for treatment of the process wastewater. Constructed wetlands are simple to operate and have low operating and maintenance costs. Elimination of odors and conservation of nutritive value in the wastewater will facilitate reuse of the wastewater. The industry will be able to supply area farmers with odor free wastewater that can be used to supplement crop nutrient requirements. The research will improve understanding of anaerobic microbial ecology and odor generation in food processing wastewater. The results will be applicable to other treatment and disposal technologies.
