Ammonia oxidation at low temperature in a high concentration powdered activated carbon membrane bioreactor

2002 ◽  
Vol 2 (2) ◽  
pp. 169-176 ◽  
Author(s):  
G. Seo ◽  
S. Takizawa ◽  
S. Ohgaki
Keyword(s):  
Activated Carbon ◽  
Water Temperature ◽  
Membrane Bioreactor ◽  
Ammonia Oxidation ◽  
Hollow Fiber Membrane ◽  
Powdered Activated Carbon ◽  
Carbon Membrane ◽  
High Concentration ◽  
Filtration Resistance ◽  
Cake Layer

In this study, a membrane bioreactor (MBR) with high concentration of powdered activated carbon was investigated to enhance the oxidation of ammonia at a water temperature lower than 4°C. A semi-pilot scale submersed suction type MBR was operated with a hollow fiber membrane module having a nominal pore size of 0.1μm and an effective filtration area of 0.05 m2. A powder activated carbon (PAC) concentration of 40 g/L was maintained in the reactor and the PAC was not replaced during the experiment. A control reactor without PAC was also operated for comparison. Water temperature of both reactors was controlled at 25, 10, 4 and 2°C. At a water temperature of 4°C, the influent ammonia nitrogen of 10 mg/L was removed completely in the reactor with PAC. On the other hand, the effluent concentration of the control reactor was fluctuated in a range of 3-6 mg/L. In addition, nitrite nitrogen was detected in the control reactor up to a maximum concentration of 6 mg/L at the same temperature. Still high removal efficiency was obtained in the reactor with PAC even at 2°C, but almost no ammonia oxidation was observed in the control reactor. The average ammonia oxidation rate of the powdered activated carbon reactor was 1.3-3.2 mg/L.h, which is 4.5 times higher than that of the control (0.51-0.63 mg/L.h). Filtration resistance was 2.45 × 1012m-1 for the reactor with PAC, which is one order lower than that of the control reactor (1.64 × 1013m-1). The microbial cake layer on the membrane surface caused the larger filtration resistance for the control reactor. Only one chemical cleaning was conducted for the membrane in the PAC reactor at the flux of 0.4-0.7 m/d while 3 times cleaning was required for that of the control.

Long term operation of high concentration powdered activated carbon membrane bio-reactor for advanced water treatment

2004 ◽  
Vol 50 (8) ◽  
pp. 81-87 ◽  
Author(s):  
G.T. Seo ◽  
C.D. Moon ◽  
S.W. Chang ◽  
S.H. Lee
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Membrane Bioreactor ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Powdered Activated Carbon ◽  
Carbon Membrane ◽  
High Concentration ◽  
Term Operation ◽  
Nakdong River Basin

A pilot scale experiment was conducted to evaluate the performance of a membrane bioreactor filled with high concentration powdered activated carbon. This hybrid system has great potential to substitute for existing GAC or O3/BAC processes in the drinking water treatment train. The system was installed at a water treatment plant located downstream of the Nakdong river basin, Korea. Effluent of rapid sand filter was used as influent of the system which consists of PAC bio-reactor, submerged MF membrane module and air supply facility. PAC concentration of 20 g/L was maintained at the beginning of the experiment and it was increased to 40 g/L. The PAC has not been changed during the operational periods. The membrane was a hollow fiber type with pore sizes of 0.1 and 0.4 µm. It was apparent that the high PAC concentration could prevent membrane fouling. 40 g/L PAC was more effective to reduce the filtration resistance than 20 g/L. At the flux of 0.36 m/d, TMP was maintained less than 40 kPa for about 3 months by intermittent suction type operation (12 min suction/3 min idling). Adsorption was the dominant role to remove DOC at the initial operational period. However the biological effect was gradually increased after around 3 months operation. Constant DOC removal could be maintained at about 40% without any trouble and then a tremendous reduction of DBPs (HAA5 and THM) higher than 85% was achieved. Full nitrification was observed at the controlled influent ammonia nitrogen concentration of 3 and 7 mg/L. pH was an important parameter to keep stable ammonia oxidation. From almost two years of operation, it is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment under the recent situation of more stringent DBPs regulation in Korea.

A pilot-scale study of a powdered activated carbon-membrane bioreactor for the treatment of water with a high concentration of ammonia

2016 ◽  
Vol 2 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Senlin Shao ◽  
Fangshu Qu ◽  
Heng Liang ◽  
Haiqing Chang ◽  
Huarong Yu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Membrane Bioreactor ◽  
Pilot Scale ◽  
Ammonia Removal ◽  
Powdered Activated Carbon ◽  
Carbon Membrane ◽  
High Concentration

Ammonia removal was highly impacted by temperature and alkalinity. Fouling cake could remove a certain amount of ammonia.

scholarly journals Model-based evaluation of fouling mechanisms in powdered activated carbon/membrane bioreactor system

2019 ◽  
Vol 79 (10) ◽  
pp. 1844-1852 ◽  
Author(s):  
Juan Xiong ◽  
Xingtao Zuo ◽  
Shi Zhang ◽  
Wei Liao ◽  
Zhongbing Chen
Keyword(s):  
Activated Carbon ◽  
Membrane Bioreactor ◽  
Powdered Activated Carbon ◽  
Transmembrane Pressure ◽  
Carbon Membrane ◽  
Complete Model ◽  
Constant Flow Rate ◽  
Fouling Mechanism ◽  
Cake Layer ◽  
Mean Square Errors

Abstract Identifying the fouling degree of a membrane bioreactor (MBR) provides guidance on the determination of suitable membrane cleaning methods. There is still a lack of knowledge on the effects of powdered activated carbon (PAC) refresh ratio on the MBR fouling mechanism. Major fouling mechanisms of an MBR with constant flow rate at different PAC replenishment ratios were investigated by individual and combined mechanistic fouling models. The root mean square errors were employed to assess the prediction accuracy of the used fouling models. The combined models showed better prediction. The cake–complete model provided far better fits of the transmembrane pressure data, and provided good fits of other individual model predictions regardless of the PAC refreshment ratio. Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy confirmed that the cake layer clogging was the main fouling mechanism followed by complete blockage and standard plugging. The cake–complete model may be used to predict the fouling mechanisms in PAC/MBR systems.

Domestic wastewater reclamation by submerged membrane bioreactor with high concentration powdered activated carbon for stream restoration

2004 ◽  
Vol 50 (2) ◽  
pp. 173-178 ◽  
Author(s):  
G.T. Seo ◽  
H.I. Ahan ◽  
J.T. Kim ◽  
Y.J. Lee ◽  
I.S. Kim
Keyword(s):  
Activated Carbon ◽  
Stream Restoration ◽  
Reclaimed Water ◽  
Domestic Wastewater ◽  
Powdered Activated Carbon ◽  
Urban Stream ◽  
Wastewater Reclamation ◽  
High Concentration ◽  
K Value ◽  
Cake Layer

This study focuses on the practical application of high concentration powdered activated carbon coupled membrane bio-reactor to domestic wastewater reclamation. The study was conducted in three parts, such as analysis of secondary domestic wastewater effluent, design and operation parameter evaluation and reclaimed water quality estimation for stream restoration. The organic concentration was 25.2-80.2 mgCODCr/L for the effluent of three domestic wastewater treatment plants. Around 50-75% of the COD was low molecular substances less than 1,000 which were quite biodegradable. The sawdust PAC was estimated to be proper adsorbent for the organics in the secondary effluents. Its Freundlich constant, K value was 5.847 and 1/n, 0.36. Using a system consists of single reactor with high concentration PAC (80 g/L) and submerged hollow fiber MF membrane module with nominal pore size of 0.1 μm, design and operation parameters were obtained, such as HRT of the bioreactor (2.5 hr), PAC concentration (80 g/L), the initial ßux (less than 0.5 m/day) and intermittent suction cycle (12 min. suction and 3 min. idling). Organic removal by the system was high enough to produce reclaimed water for urban stream restoration The effluent organic concentration was at the level of 2 mg/L in terms of TOC (around 5 mg/L as CODCr). Substances with molecular weight cut off <1,000 were removed mostly by adsorption and biodegradation. Those above 1,000 were rejected at PAC cake layer on the membrane and gradually degraded by microorganisms during extended contact.

Factors causing PAC cake fouling in PAC–MF (powdered activated carbon-microfiltration) water treatment systems

2005 ◽  
Vol 51 (6-7) ◽  
pp. 231-240 ◽  
Author(s):  
P. Zhao ◽  
S. Takizawa ◽  
H. Katayama ◽  
S. Ohgaki
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Membrane Surface ◽  
Pilot Scale ◽  
Powdered Activated Carbon ◽  
Raw Water ◽  
Permeate Flux ◽  
Void Space ◽  
High Concentration ◽  
Cake Layer

Two pilot-scale powdered activated carbon–microfiltration (PAC–MF) reactors were operated using river water pretreated by a biofilter. A high permeate flux (4 m/d) was maintained in two reactors with different particle sizes of PAC. High concentration (20 g/L) in the PAC adsorption zone demonstrated 60–80% of organic removal rates. Analysis on the PAC cake fouling demonstrated that attached metal ions play more important role than organic matter attached on PAC to the increase of PAC cake resistance. Effects of factors which may cause PAC cake fouling in PAC-MF process were investigated and evaluated by batch experiments, further revealing that small particulates and metal ions in raw water impose prominent influence on the PAC cake layer formation. Fe (II) precipitates after being oxidized to Fe (III) during PAC adsorption and thus Fe(III) colloids display more significant effect than other metal ions. At a high flux, PAC cake layer demonstrated a higher resistance with larger PAC due to association among colloids, metals and PAC particles, and easy migration of small particles in raw water into the void space in the PAC cake layer. Larger PAC possesses much more non-uniform particle size distribution and larger void space, making it easier for small colloids to migrate into the voids and for metal ions to associate with PAC particles by bridge effect, hence speeding up and intensifying the of PAC cake fouling on membrane surface.

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