Effects of porous carrier size on biofilm development, microbial distribution and nitrogen removal in microaerobic bioreactors.
In this study, effects of porous carrier's size (polyurethane-based) on microbial characteristics were systematically investigated in addition to nitrogen removal performance in six microaerobic bioreactors. Among different sized carriers (50, 30, 20, 15,10, 5mm), 15mm carrier showed highest nitrogen removal (98%) due to optimal micro-environments created for aerobic nitrifiers in outer layer (0-7mm), nitrifiers and denitrifiers in middle layer (7-10mm) and anaerobic denitrifiers in inner layer (10-15mm). Candidatus brocadia, a dominant anammox bacteria, was solely concentrated close to centroid (0-70μm) and strongly co-aggregated with other bacterial communities in the middle layer of the carrier. Contrarily, carriers with a smaller (<15mm) or larger size (>15mm) either destroy the effective zone for anaerobic denitrifiers or damage the microaerobic environments due to poor mass transfer. This study is of particular use for optimal design of carriers in enhancing simultaneous nitrification-denitrification in microaerobic wastewater treatment processes.
Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
Muhammad
M
Ahmad
Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
Sitong
S
Liu
Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
Nasir
N
Mahmood
Department of Physics, South University of Sciences and Technology, Shenzhen, China.
Asif
A
Mahmood
Water Desalination and Reuse Center (WDRC), Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Muhammad
M
Ali
Resources and Environmental Research Academy, North China Electric Power University, Beijing, China.
Maosheng
M
Zheng
Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China. Electronic address: nijinren@iee.pku.edu.cn.
Jinren
J
Ni
D000641:Ammonia / Q000302:isolation & purification*; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology; D058440:Denitrification; D061328:Planctomycetales / Q000502:physiology*; D011140:Polyurethanes / Q000737:chemistry; D016062:Porosity; D013499:Surface Properties; D062065:Wastewater; D018508:Water Purification
D000641:Ammonia; D011140:Polyurethanes; D062065:Wastewater
Candidatus brocadia; Carrier size; Co-aggregation; Microbial distribution; Simultaneous nitrification and denitrification; Wastewater treatment