This study investigated the effect of high concentration of free ammonia on microalgal growth and substrate removal by applying real wastewater nitrogen ratio. To test of this, the conditions of free ammonia 1, 3, 6, 9, 12, 15 mg-N/L are compared. After 3 days of incubation, algal growth of Chlorella vulgaris and carbon removal rate are respectively lower in the reactors of FA 12, 15 mg-N/L compared to the others. This indicates that the high concentration of free ammonia, in this case, above 12 mg-N/L, has negative effect on algal growth and metabolic activity. Also, high concentration of free ammonia causes the proton imbalance, ammonium accumulation in algae and has toxicity for these reasons. So, we have to consider free ammonia in applying the microalgae to wastewater treatment system by the way of diluting wastewater or controlling pH and temperature.

• 김은지(경희대학교 공과대학 환경학 및 환경공학과) | Eun-Ji Kim (Department of Environmental Science and Engineering, Kyung Hee University)
• 조재형(경희대학교 공과대학 환경학 및 환경공학과) | Jae Hyung Cho (Department of Environmental Science and Engineering, Kyung Hee University)
• 노경호(경희대학교 공과대학 환경학 및 환경공학과) | Kyung Ho Noh (Department of Environmental Science and Engineering, Kyung Hee University)
• 남귀숙(한국농어촌공사 농어촌연구원) | Nam guisook (Korea Rural Community Corporation)
• 황선진(경희대학교 공과대학 환경학 및 환경공학과) | Sun-Jin Hwang (Department of Environmental Science and Engineering, Kyung Hee University) Corresponding author