scholarly journals Simultaneous Nitrification and Denitrification using Activated Sludge Entrapped in Polyethylene Glycol Prepolymer

2007 ◽  
Vol 43 (3) ◽  
pp. 121-128 ◽  
Author(s):  
TATSUO SUMINO ◽  
KAZUICHI ISAKA ◽  
HAJIME IKUTA ◽  
BASSEM OSMAN
2015 ◽  
Vol 73 (4) ◽  
pp. 827-834 ◽  
Author(s):  
Yang Bai ◽  
Yaobin Zhang ◽  
Xie Quan ◽  
Shuo Chen

An integrated fixed-film activated sludge (IFAS) process (G1) and an activated sludge anoxic–oxic process (G2) were operated at nitrate liquor recirculation ratio (R) of 100, 200 and 300% to investigate the feasibility of enhancing nitrogen removal efficiency (RTN) and reducing R by improving simultaneous nitrification and denitrification (SND) in the IFAS process. The results showed that the effluent NH4+-N and total nitrogen (TN) of G1 at R of 200% were less than 1.5 and 14.5 mg/L, satisfying the Chinese discharge standard (NH4+-N < 5 mg/L; TN < 15 mg/L). However, the effluent NH4+-N and TN of G2 at R of 300% were higher than 8.5 and 15.3 mg/L. It indicated that better RTN could be achieved at a lower R in the IFAS process. The polymerase chain reaction–denaturing gradient gel electrophoresis results implied that nitrifiers and denitrifiers co-existed in one microbial community, facilitating the occurrence of SND in the aerobic reactor of G1, and the contribution of SND to TN removal efficiency ranged 15–19%, which was the main reason that the RTN was improved in the IFAS process. Therefore, the IFAS process was an effective method for improving RTN and reducing R. In practical application, this advantage of the IFAS process can decrease the electricity consumption for nitrate liquor recirculation flow, thereby saving operational costs.


2011 ◽  
Vol 396-398 ◽  
pp. 1944-1949
Author(s):  
Cai Yan He ◽  
Yan Xu ◽  
Yan Yan Chen ◽  
Sheng Yu ◽  
Jing Ming Liu

Aiming at the problem of lower removal efficiency of ammonia nitrogen in the activated sludge process for wastewater treatment plant of Jilin Chemical Company, a few tests were studied such as filler selection, biological hydrolysis-acidification process, nitrobacteria cultivation, activated sludge process and biofilm process, the feasibility of simultaneous nitrification and denitrification(SND) was developed with biofilm treatment for chemical poor-biological wastewater. The results showed that: SND occurred in the aerobic section, effluent total basicity (TB) in biofilm process was 2mmol / L or more, and was higher than activated sludge process, while the effluent TB in activated sludge process was about 0.1mmol / L,and nitrate produced by activated sludge process was 30mg/L higher than that of biofilm process. Nitrogen removal efficiency using SJ-1-type filler made in Jiangsu Suzhou Purification Group Co., Ltd was 15.01% more than that using combined filler.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Tao Zhang ◽  
Chaohai Wei

This study presented the performance of simultaneous nitrification and denitrification (SND) process using a new developed hybrid airlift reactor which integrated the activated sludge reaction process in the airlift reactor and the sludge settling separation process in the clarifier. The proposed reactor was started up successfully after 76 days within which the COD and total nitrogen removal rate can reach over 90% and 76.3%, respectively. The effects of different COD/N and DO concentrations on the performance of reactor were investigated. It was found that the influent COD/N maintained at 10 was sufficient for SND and the optimum DO concentration for SND was in the range of 0.5 to 0.8 mg L−1. Batch test demonstrated that both macroscopic environment caused by the spatial DO concentration difference and microscopic environment caused by the stratification of activated sludge may be responsible for the SND process in the reactor. The hybrid airlift reactor can accomplish SND process in a single reactor and in situ automatic separation of sludge; therefore, it may serve as a promising reactor in COD and nitrogen removal fields.


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