Max Gangestad Martin Gross PhD Zhiyou Wen PhD New Algae Treatment Technology Addresses Stricter Wastewater Regulations for Rural Iowa Max Gangestad Martin Gross PhD Zhiyou Wen PhD

Problem Iowa Towns With Lagoon Treatment Iowa Cities with Lagoon System 584 Iowa Citizens using Lagoon System 605,110 New wastewater regulations in Iowa require reduction of nutrients Substantial economical cost to rural Iowa towns Biggest impact on lagoon system communities

Solution Revolving Algal Biofilm (RAB) Technology invented at ISU using algae to efficiently remove nutrients Potential to greatly reduce cost for small towns

Nutrient Removal Process

Average Cost for New System Total Cost for All Lagoons in Iowa Impact Mechanized Plant RAB System Amount Saved Average Cost for New System $5M $1.5M $3.5M Total Cost for All Lagoons in Iowa $2.9B $876M $2B Cost per Citizen $4,825 $1,447 $3,378

Pilot-Scale Research Pilot-scale research of RAB system in Dallas Center, IA Results are critical in identifying optimal operational parameters prior to full-scale Hydraulic retention time Nutrient removal in varying climate DNR approval

Results: Ammonia Removal Ammonia Removal Percentage 24 Hour 92% 4 Hour 72% 0.8 Hour 55%

Fertilizer Research Using algae as fertilizer compared to purchased fertilizers Amount of nitrogen applied was standardized between all samples Identical growing conditions

Fertilizer Test Results

Summary New regulations put an economic strain on rural Iowa towns. RAB technology has the potential to greatly reduce that strain on small towns and offer a fertilizer byproduct. However, pilot-scale research is required in order to gain regulatory approval and determine optimal operating conditions.

Acknowledgements Partners: City of Dallas Center Funding: Partners: City of Dallas Center Horticulture Department Biocentury Research Farm

QUESTIONS? Max Gangestad Email: mtgang@iastate.edu