International Journal of Waste Resources

Membrane-based dewatering processes using FO and MD for nitrogen recovery from wastewater

4^th World Congress and Expo on Recycling

July 27-29, 2017 | Rome, Italy

Hyokwan Bae, Dawoon Jeong, Lat Lat Tun, Seongpil Jeong, Kyungjin Cho and Seockheon Lee

Pusan National University, South Korea
Korea Institute of Science and Technology, South Korea
Yangon Technological University, Myanmar

Scientific Tracks Abstracts: Int J Waste Resour

Abstract:

Forward osmosis (FO) and biological nitrification processes were integrated in this study. High strength ammonia wastewater of 2500 mg-N/L was partially nitrified at an ammonia conversion rate of 1.34±0.25 kg-N/m3-day under the limitation of an acidification buffer, i.e., HCO3�??-C/NH4+-N = 1, as a control factor. To mitigate the membrane fouling, direct contact between the biomass and cellulose triacetate FO membrane was avoided by employing PVA/alginate-immobilized nitrifiers in the bioreactor. The simultaneous FO process concentrated the wastewater at concentration factors (CFs) of up to 2.34 during the partial nitritation (PN) reaction. As a result, the concentration of total dissolved solids (TDS) ranged from 13.6 g/L to 35.7 g/L. It was found that salinity higher than 17 g-TDS/L inhibited the activity of the nitrite-oxidizing bacteria, but not the ammonia-oxidizing bacteria. Then, the nitrogen content of wastewater was further concentrated using direct contact membrane distillation (DCMD). The ratio of transferred ammonia to water (i.e., specific ammonia transfer: SAT) was controlled by operational conditions of membrane materials, pH and temperature. It was identified that free ammonia (FA) concentration has a critical role on SAT values under different total ammoniacal nitrogen concentration and pH. Thus, the acidification pretreatment was essential to minimize the FA concentration in the feed before operating the DCMD system. Taken together, membrane-based dewatering processes were effective to reduce the water contents in the wastewater and the remained nitrogen contents can be utilized as a concentrated fertilizer.

Biography :

Hyokwan Bae has been working at Korea Institute of Science and Technology as a Research Scientist for 11 years (2006-2017). He participated in a number of research projects on nitrogen removal, membrane separation, biofilm and culture-independent analysis of bacterial community structure. After obtaining a PhD degree in Interdisciplinary Program of Bioengineering at Seoul National University in early 2014, his research has been concentrated on the integration of biological reaction and membrane separation processes linked to obtaining high quality reclaimed water and resource recovery (e.g., partial nitrification, halophilic bacteria, forward osmosis, membrane distillation and fouling control). Recently, he joined the Faculty of Pusan National University in 2017 to broaden and improve his specialty in Civil and Environmental Engineering.

Email: hyokwan.bae@pusan.ac.kr