Acetate, propionate, butyrate are the major soluble volatile fatty acids metabolites of fermented food waste leachates. This work investigate the effects of volatile fatty acid on the growth rate and NH4-N, PO4-P removal efficiency of mixotrophic microalgae Chlorella vulgaris to treat digested food waste leachates. The results showed that acetate, propionate and butyrate were efficiently utilized by Chlorella vulgaris and microalgae growth was higher than control condition. Similar trends were observed upon NH4-N and PO4-P consumption. Volatile fatty acids promoted Chlorella vulgaris growth, and nutrient removal efficiencies were highest when acetate was used, and butyrate and propionate showed second and third. From this work it could be said that using mixotrophic microalgae, in this work Chlorella vulgaris, fermented food waste leachates can be treated with high efficiencies.

This study investigated the effect of NH4 + concentrations on microalgae growth by appling mixotrophic microalgae chlorella vulgaris in order to treat anaerobic digested food waste leachate. The growth rate and final microalgae growth were an order as 400 > 100 > 800 > 1300 mg-N/L. As results, The growth rate and final growth of microalgae were highest at ammonia concentration of 400 mg-N/L, On the other hand microalgae growth was inhibited when ammonia concentrations were over 800 mg-N/L. high concentrations of nitrogen over 800 mg-N/L interrupt the growth of microalgae. All of nitrogen and phosphorus were removed by microalgae at the ammonia concentration of 100~400 mg-N/L. In addition, when ammonia concentration was over 800 mg-N/L, the removal of nitrogen and phosphorus was limited mainly due to the microalgae growth limit. It was possible to treat anaerobic digested food waste leachate with mixotrophic microalgae when the ammonia concentration was controlled below 400 mg-N/L.