The role of interactions of effective biofilm surface area and mass transfer in nitrogen removal efficiency of an integrated fixed-film activated sludge system

2018 ◽  
Vol 350 ◽  
pp. 992-999 ◽  
Author(s):  
Yiwen Liu ◽  
Chunyan Li ◽  
Susanne Lackner ◽  
Michael Wagner ◽  
Harald Horn
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.


2019 ◽  
Vol 9 (2) ◽  
pp. 17-27
Author(s):  
Nway Nway Khaing ◽  
Theingi Ye Myint ◽  
Cho Cho Thin Kyi

This research was carried out using lab-scaled Integrated Fixed Film Activated Sludge (IFAS) process with fabious media and anoxic process in order to reduce the concentration of ammonia nitrogen and nitrate nitrogen in municipal wastewater from Yangon City, Myanmar. The required wastewater sample was collected from the wastewater treatment plant of Yangon City Development Committee (YCDC). Ten experiments were conducted with five operational conditions and they lasted about four months from February to May 2018. The rate of air supply for the aeration tank through these experiments was about 8 m3 /day. This paper describes the evaluation on nitrogen removal efficiency of the lab-scaled treatment system depending on the results from the experiments. Due to the different operational conditions through these experiments, the F/M ratio of IFAS process varied between 0.1 and 0.9 d -1 and SRT of IFAS process ranged between 6.0 days and 8.3 days. Moreover, the F/M ratio fluctuated between 0.2 d -1 and 0.7 d -1 as well as the Specific Rate of Denitrification (SRDN) altered between 0.23 g NO3-N/g MLSS and 0.33 g NO3-N/g MLSS in the anoxic process. According to the outcomes of the experiments, the maximum removal efficiency for ammonia nitrogen and nitrate nitrogen were about 98.2% and 97.7%, respectively. However, the optimum treatment efficiency for both NH3-N and NO3-N concentration was obtained at the ninth experiment with about 0.1 d-1 of the F/M ratio and about 6.4 days of SRT in aerobic reactor while the F/M ratio, SRDN and anoxic residence time of anoxic process were about 0.26 d-1 , 0.27 g NO3-N/ g MLSS and 48 hours, respectively. About 500 mg/l of ammonia nitrogen can be reduced to about 30 mg/l and about 2600 mg/l of nitrate nitrogen can be reduced to about 61 mg/l, respectively in this ninth experiment. The optimum treatment efficiency for ammonia nitrogen and nitrate nitrogen were about 94.0 % and 98.0 %, respectively.


2017 ◽  
Vol 41 (2) ◽  
pp. 237-247 ◽  
Author(s):  
Paul Moretti ◽  
Jean-Marc Choubert ◽  
Jean-Pierre Canler ◽  
Pierre Buffière ◽  
Olivier Pétrimaux ◽  
...  

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.


2010 ◽  
Vol 113-116 ◽  
pp. 2201-2207 ◽  
Author(s):  
Jun Yin ◽  
Lei Wu ◽  
Ke Zhao ◽  
Yu Juan Yu

In this article, analysis the start-up of A2/O humic activated sludge system phosphorus removal efficiency and the characteristics of anaerobic phosphorus release, aerobic phosphorus uptake, sludge activity and their change in the Series Technologies process. The results show that A2/O humic activated sludge system phosphorus removal rate stabilized at 90.7% ~ 97.6%. Sludge activity except for anoxic zone 2 increased, along the process showed a gradual decrease trend.


1996 ◽  
Vol 33 (12) ◽  
pp. 155-162 ◽  
Author(s):  
Clifford W. Randall ◽  
Dipankar Sen

One of the two trains of the 37,000 m3/d Annapolis, Maryland step aeration activated sludge treatment plant was modified for single-sludge anoxic-aerobic operation, and then fixed-film media were integrated into the aerobic zone to enhance nitrification. Rope-like Ringlace media was selected for integration, and 30,000 meters were installed in a volume of 475 m3 for a pilot demonstration. The purpose of the integrated fixed-film media was to upgrade the short hydraulic retention time (HRT) basin (6 hrs nominal) for efficient, year-round nitrogen removal without construction to increase basin volume. An engineering study had concluded that upgrading the facility for year round complete nitrification, without nitrogen removal, would cost US$24 million. The modified train was operated for 12 months, six in the plug-flow MLE configuration, and six in a step-feed configuration. The integrated Ringlace media increased the nitrification rate per unit volume to 225% of that observed in the control section, attaining a value of 1.75 kg/d NH3-N per linear meter at 15°C. The media also increased denitrification in the aerobic media section to the extent that between 30 and 88% of the nitrates formed in the section were denitrified within it, permitting a potential 25% or more reduction in the volume of the anoxic zone. An IFAS retrofit design was developed which incorporated step-feed operation, and reduced the projected construction cost to US$9.2 million.


2012 ◽  
Vol 610-613 ◽  
pp. 1454-1458
Author(s):  
Ming Fen Niu ◽  
Hong Jing Jiao ◽  
Li Xu ◽  
Yan Yu ◽  
Jian Wei

A2N is two-sludge system, by using the method that first bringing up the cultivation of denitrifying phosphorus removing bacteria (DPB) and nitrification biofilm separately then connecting them, which can start up A2N system successfully. Nitrification biofilm was cultivated in a sequencing batch reactor (SBR). After 30 days, NH4+-N effluent concentration steadily stayed below 0.5mg·L-1.In another SBR, the activated sludge for the enrichment of DPB is from the anaerobic tank, which was firstly operated under anaerobic/aerobic (A/O) condition. After 20 days, PAOs was successfully enriched. Then, the activated sludge was conducted under anaerobic/anoxic/aerobic (A/A/O) condition, maintaining the anaerobic time, gradually increased anoxic time and induced aerobic time. After 30 days DPB was successfully enriched, two phases totally take 50 days. The removal efficiency of total nitrogen and phosphorus are above 85 % and 95 %, so that A2N system was started up successfully.


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