GROWING MICROALGAE IN LIVESTOCK WASTEWATER - BENEFITS IN NUTRIENT RECYCLE, ANTIBIOTIC REMOVAL, AND POTENTIAL BIOFUEL PRODUCTION

The improper management of livestock wastewater has deteriorated freshwater ecosystems due to the heavy loads of nutrients and antibiotics. Large-scale livestock farms with concentrated animal feeding operations have replaced traditional household breeding to meet the increasing demand for animal products. However, this transformation has generated a large volume of livestock wastewater with high nutrient and antibiotic concentrations. It is a particular concern on reducing loads of nutrients and antibiotics from livestock wastewater to surrounding water bodies. Using wastewater to cultivate microalgae has recently attracted broad attention due to its advantages of using nutrients for microalgae growth, removing micropollutants, and bringing additional values via using microalgae for biofuel production. To identify the best management practices for nutrient and antibiotic removals, we propose a four-year study with three specific objectives: (1) identifying effective microalgae strains and (2) optimizing controlling factors for nutrient and antibiotic removals, and (3) developing process models for prediction and optimization. We will conduct laboratory experiments to examine the influence of microalgae strains, initial nutrients, pond depth, resident time, etc., on nutrient and antibiotic removals. With support from the Piedmont Research and Education Center at Clemson University, we will use livestock wastewater to cultivate microalgae in three storage ponds for over one year. We will use the laboratory and field data to develop the process models to predict microalgae growth and nutrient removals and optimize pond operations and management practices for maximum nutrient removals. Additionally, we will use microalgae for biofuel production and conduct the techno-economic and life cycle analyses.