Enhanced short-cut nitrification in an airlift reactor by CaCO3 attachment on biomass under high bicarbonate condition.
The short-cut nitrification (SCN) performance of an airlift reactor (ALR) was investigated under increasing bicarbonate condition. The sequential increase of bicarbonate from 2.5 to 7.0 g/L accelerated the nitrite accumulation and improved the NAP to 99 %. With the increase of bicarbonate dose to 11 g/L, the ammonium removal efficiency and the ammonium removal rate (ARR) were improved to 95.1 % and 0.57 kg/m(3)/day, respectively. However, the elevation of bicarbonate concentration from 11.0 to 14.0 g/L gradually depreciated the nitrite accumulation percentage to 62.5 %. Then, the reactor was operated in increasing ammonium strategy to increase the nitrogen loading rate (NLR) to 1.1 kg/m(3)/day under 700 mg/L influent ammonium concentration. The ARR and nitrite production rate were elevated to 1.1 and 0.9 kg/m(3)/day, respectively. The SCN performance was improved to 1.8 kg/m(3)/day (NLR) by the subsequent progressive shortening of HRT to 4.8 h at ammonium concentration of 350 mg/L, which was 1.6 times higher than that of the increasing ammonium strategy. Chemical analysis with EDS, FTIR and XRD confirmed the presence of CaCO3 precipitates on biomass surface during the long-term operation under high bicarbonate conditions. The attachment of precipitates to the SCN sludge helped to improve the biomass settleability and finally enhanced the SCN performance of the ALR.
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China.
Mohammad
M
Ali
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China.
Li-Yuan
LY
Chai
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China. 1971256223@qq.com.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China. 1971256223@qq.com.
Hai-Ying
HY
Wang
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China. chjtang@csu.edu.cn.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China. chjtang@csu.edu.cn.
Chong-Jian
CJ
Tang
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China.
Xiao-Bo
XB
Min
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China.
Xu
X
Yan
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China.
Cong
C
Peng
Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha, 410083, Hunan, China.|National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China.
Yu-Xia
YX
Song
Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China.
Ping
P
Zheng
D064751:Ammonium Compounds / Q000378:metabolism; D001639:Bicarbonates / Q000737:chemistry*; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors; D002119:Calcium Carbonate / Q000737:chemistry*; D058465:Nitrification; D014865:Waste Disposal, Fluid
D064751:Ammonium Compounds; D001639:Bicarbonates; D002119:Calcium Carbonate
Airlift reactor; Bicarbonate; Biological nitrogen removal; CaCO3 attachment; Short-cut nitrification