Full-scale evaluation of an integrated fixed-film activated sludge (IFAS) process for enhanced nitrogen removal

1996 ◽  
Vol 33 (12) ◽  
pp. 155-162 ◽  
Author(s):  
Clifford W. Randall ◽  
Dipankar Sen
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Plug Flow ◽  
Treatment Plant ◽  
Nitrification Rate ◽  
A Value ◽  
Fixed Film ◽  
Control Section ◽  
The Media ◽  
Retrofit Design

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.

Full scale evaluation of nitrification performance in an integrated fixed film activated sludge process

1998 ◽  
Vol 38 (1) ◽  
pp. 71-78 ◽  
Author(s):  
R. M. Jones ◽  
D. Sen ◽  
R. Lambert
Keyword(s):  
Activated Sludge ◽  
Monitoring And Evaluation ◽  
Full Scale ◽  
Nitrification Rate ◽  
Operating Period ◽  
Monitoring Period ◽  
Media Frames ◽  
Average Temperature ◽  
Fixed Film ◽  
The Media

The nitrification performance of an integrated fixed film activated sludge (IFAS) process was compared to a parallel control system at full scale. The IFAS process utilized the Ringlace and Biomatrix looped cord media products. Monitoring and evaluation of the retrofit was divided into two periods. The first monitoring period was from October 3, 1995 to June 20, 1996. The second monitoring period was started on December 2, 1996 and was completed on March 28, 1997. During the first operating period, the maximum media nitrification rate was estimated to be 0.42 kg/d/1000 m of media at an average temperature of 10°C. Settling was also improved. To correct flow short circuiting observed during the first operating period additional aerators were mounted below the media frames and baffles were mounted above existing diffusers. Nitrification performance of the media during the second operating period was found to be marginal. Although the nitrification performance in the control train was not stressed to the same degree as in the 1995/96 period, the likely main cause of the deteriorated performance of the media was a proliferation of bristle worm in the biofilm. The results of this study indicate that proper aeration design, and the prevention and treatment of worm blooms are two important issues in the application of the IFAS process.

Performance of fixed film media integrated in activated sludge reactors to enhance nitrogen removal

1994 ◽  
Vol 30 (11) ◽  
pp. 13-24 ◽  
Author(s):  
Dipankar Sen ◽  
Pramod Mitta ◽  
Clifford W. Randall
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Biofilm Growth ◽  
Ammonium N ◽  
Suspended Growth ◽  
Fixed Film ◽  
The Media ◽  
Aerobic Zone ◽  
Sponge Media ◽  
Aerobic Cell

Nitrification and denitrification were evaluated in multiple CSTR continuous flow fixed film systems at 12°C. Three systems were operated with three types of media installations and a fourth as a control without media. The media configurations evaluated included: (i) frame mounted fine pore sponge media supported on wires; (ii) free floating fine pore sponge media; and (iii) fixed location frame mounted rope media (ringlace). The pore size for sponge media was 14 pores per centimeter. Each system included a two-cell anaerobic zone with 17 percent of total volume, two-cell anoxic zone with 17 percent of total volume, and a three-cell aerobic zone with 64 percent of total volume. The multi-cell configuration was used to maximize kinetics of removal with suspended growth biomass and evaluate improvements in nitrogen removal beyond the levels achieved with suspended growth. At the optimum location (aerobic cells 1 and 2), the nitrification in cells containing free-floating sponges was 143 percent of the control at aerobic MCRTs of 3.1 and 3.4 days, with 35 percent media volume to cell volume. The nitrification with rope media was 136 percent of the control in middle third of the aerobic zone. Removals with ringlace were poorer in the first aerobic cell operating at higher COD levels, and in the third aerobic cell which did not contain sufficient biofilm growth at low levels of COD. Nitrification was 14 percent higher in Systems 1 and 2 with fixed and free floating sponges, respectively, and 8 percent higher in System 3 (ringlace) when all systems were spiked with 20 mg/L additional ammonium over a 24 hour period. Optimizing location of the media, with higher density of media at locations where adequate COD and ammonium-N are available for biofilm growth increase nitrification on media. Studies in full scale systems show that COD and ammonium-N concentrations at downstream locations in the activated sludge basin increase during peak flows and with step feed of wastewater. This helps increase biofilm growth and improve nitrification on the media downstream locations. Denitrification observed in the aerobic cells of the fixed film systems was in excess of the control. All aerobic cells were operated at D.O. levels in excess of 6.0 mg/L. The fraction of total denitrification under aerobic conditions was 0.0 in the control as compared to 0.14 to 0.24 with ringlace media and fixed sponge media, respectively, at an aerobic MCRT 3.1 days. Fraction aerobic denitrification in all systems increased with an increase in MCRT of suspended growth - to 0.21 in the control and 0.35 and 0.39 with ringlace and sponges, respectively, at aerobic MCRTs of 3.4 to 7.7 days.

Process evaluation of HASP with IMET system through SNR and SDNR for the efficient management of Sewage Treatment Plant

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Young H. Yoon ◽  
Jae R. Park ◽  
Sang W. Ahn ◽  
Kwang B. Ko ◽  
Kyung J. Min ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Linear Regression Analysis ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Reaction Rates ◽  
Nitrification Rate ◽  
Activated Sludge Process ◽  
Type Experiment ◽  
Batch Type ◽  
Nitrification And Denitrification

Hybrid Activated Sludge Process (HASP) with IMET was developed and applied to an activated sludge process for the advanced nutrient treatment in Korea. The characteristics of nitrogen removal from the HASP were investigated through a kinetic study by batch-type experiment. Online DB analysis produced from the IMET was conducted for the nutrient removal performance in the field demonstration plant treating 10,000 m3/day in G city of Korea. In this paper, we aimed to determine the effect of increasing NHM4+-N load on the specific nitrification rate (SNR) and the specific denitrification rate (SDNR) through a batch-type experiment, and to estimate the net reaction time for the phase-transfer rate using online DB analysis in the HASP operation. Experimental results include: (1) both the nitrification and denitrification followed first-order kinetics; (2) the maximum SNR and SDNR were 4.0301 mgN/gVSS·hr and 2.785 mgN/gVSS·hr, respectively; (3) comparison of reaction rates between nitrification and denitrification from the non-linear regression analysis found that nitrification rate was higher than denitrification.

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

Tertiary nitrification in pilot-plant plug-flow fixed-film reactors with long-term ammonium deficiency

1994 ◽  
Vol 29 (10-11) ◽  
pp. 61-67 ◽  
Author(s):  
M. Fruhen ◽  
K. Böcker ◽  
S. Eidens ◽  
D. Haaf ◽  
M. Liebeskind ◽  
...  
Keyword(s):  
Pilot Plant ◽  
Effective Means ◽  
Plug Flow ◽  
Nitrification Rate ◽  
Industrial Project ◽  
Transfer Processes ◽  
Fixed Film ◽  
Film Reactor ◽  
Observation Period

The objective of this study is to investigate to what extent the nitrification capacity of a pilot-plant fixed-film reactor changes during extensive periods of nutrient supply deficiency. The examined pilot-plant was an upflow reactor filled with swelling clay of medium grain size (6 to 8 mm). The experiments revealed that the maximum nitrification rate remained practically constant during the first weeks after the onset of unregulated ammonium supply. The capacity declined slowly, dropping to approximately 66% of the initial capacity after about ten weeks. Still ammonium peaks of up to 8 mg/l were readily nitrified throughout the entire period of the experiment. The reduction in nitrification capacity during the observation period did not result from decay processes of biomass but from the reactor becoming blocked and thus hampering transfer processes. It could be observed that the detached organisms attached again further up. This semi-industrial project demonstrated that a plug-flow fixed-film reactor can be used as effective means of tertiary nitrification.

Dynamic modeling of nitrogen removal for a three-stage integrated fixed-film activated sludge process treating municipal wastewater

2017 ◽  
Vol 41 (2) ◽  
pp. 237-247 ◽  
Author(s):  
Paul Moretti ◽  
Jean-Marc Choubert ◽  
Jean-Pierre Canler ◽  
Pierre Buffière ◽  
Olivier Pétrimaux ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Dynamic Modeling ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Activated Sludge Process ◽  
Fixed Film

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

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.

OPTIMIZING OPERATION OF WASTEWATER TREATMENT PLANTS BY OFFLINE AND ONLINE COMPUTER SIMULATION

1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong
Keyword(s):  
Computer Simulation ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Historical Analysis ◽  
Computer Work ◽  
Biological Phosphorus Removal ◽  
Wide Range

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.

Suspended carrier technology allows upgrading high-rate activated sludge plants for nitrogen removal via process intensification

2000 ◽  
Vol 41 (4-5) ◽  
pp. 5-12 ◽  
Author(s):  
E.v. Münch ◽  
K. Barr ◽  
S. Watts ◽  
J. Keller
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Residence Time ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Carbon Removal ◽  
Suspended Carrier ◽  
Plastic Media

The Oxley Creek wastewater treatment plant is a conventional 185,000 EP BOD removal activated sludge plant that is to be upgraded for nitrogen removal to protect its receiving water bodies, the Brisbane River and Moreton Bay. Suspended carrier technology is one possible way of upgrading this activated sludge wastewater treatment plant for nitrogen removal. Freely moving plastic media is added to the aeration zone, providing a growth platform for nitrifying bacteria and increasing the effective solids residence time (SRT). This paper presents the results from operating a pilot plant for 7 months at the Oxley Creek WWTP in Brisbane, Australia. Natrix Major 12/12 plastic media, developed by ANOX (Lund, Sweden), was trialed in the pilot plant. The pilot plant was operated with a mixed liquor suspended solids concentration of 1220 mg/L and a total hydraulic residence time of 5.4 hours, similar to the operating conditions in the full-scale Stage 1&2 works at the Oxley Creek WWTP. The plastic carriers were suspended in the last third of the bioreactor volume, which was aerated to a DO setpoint of 4.0 mg/L. The first third of the bioreactor volume was made anoxic and the second third served for carbon removal, being aerated to a DO setpoint of 0.5 mg/L. The results from the pilot plant indicate that an average effluent total inorganic nitrogen concentration (ammonia-N plus NOx−N) of less than 12 mg/L is possible. However, the effluent ammonia concentrations from the pilot plant showed large weekly fluctuations due to the intermittent operation of the sludge dewatering centrifuge returning significant ammonia loads to the plant on three days of the week. Optimising denitrification was carried out by lowering the DO concentration in the influent and in the carbon removal reactor. The results from the pilot plant study show that the Oxley Creek WWTP could be upgraded for nitrogen removal without additional tankage, using suspended carrier technology.

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