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ANAEROBIC FLUIDIZED BED WHEY TREATMENT Paul H. Boening, Visiting Assistant Professor Department of Civil Engineering State University of New York at Buffalo Buffalo, New York 14260 Vadar F. Larsen, Professor Department of Biotechnology Massey University Palmerston North, New Zealand Anaerobic processes have several advantages over aerobic processes for waste treatment. The main advantage is that anaerobic processes are energy producing, while aerobic processes are energy consuming. Anaerobic processes also have the advantage of producing lower quantities of biological solids for final disposal. The major disadvantage of anaerobic processes has been the longer hydraulic retention time required for treatment. Fixed film reactors offer a solution to the problem of long hydraulic retention times and avoid the solids separation problems associated with the anaerobic contact process. Anaerobic filters have been extensively studied after the initial work by Young and McCarty [ 1 ] and have been modified to give the characteristics of a completely mixed system by De- Walle and Chian [2). Fluidized reactors have been evaluated both for aerobic and denitrification processes [3,4] and anaerobic processes [5]. This type of reactor offers advantages over other fixed film reactors. Fluidized bed reactors have much larger specific surface areas which allows increased concentrations of microorganisms. Larger specific surface area allows shorter hydraulic retention time for the same amount of treatment or it allows the use of lower operating temperatures. Specific surface areas of 80 m2/m3 have been reported for trickling filters and 160 m2/m3 for rotating biological contactors [61. A specific surface area of 206 m2/m3 has been reported for an anaerobic filter [2] while a specific surface area of 3000 m*/m3 has been reported for a fluidized bed reactor [3]. Concentrations of microorganism of 40 g/1 are possible in denitrification processes [6) and over 30 g/1 have been measured in anaerobic processes [5]. Packed bed reactors such as anaerobic filters often experience problems of increased pressure drop due to the accumulation of biomass. To prevent plugging relatively large voidage must be maintained which limits specific surface area and biomass concentration. Fluidized bed reactors overcome these problems allowing the use of low-voidage, high-surface-area media [7]. Also, influent suspended solids are not a problem and bed material may be easily added or removed. Tapered beds offer the additional advantage of greater stability over a large range of flowrates [8J. Previous anaerobic work with fluidized bed reactors was performed on dilute waste of COD values up to 600 mg/l. Waste stabilization efficiency up to 80% was obtained at a 3 hour hydraulic detention time [5]. This chapter presents work conducted to demonstrate the potential of and evaluate kinetic coefficients, for anaerobic fluidized bed treatment of moderately strong whey wastes of 2000-7000 mg/l COD. MATERIALS AND METHODS Two fluidized bed reactors were used in this work. Reactor number one (Figure 1) was a tapered bed with a 0.095-m diameter at the top and an inlet diameter of 3.2 x 295
Object Description
Purdue Identification Number | ETRIWC198234 |
Title | Anaerobic fluidized bed whey treatment |
Author |
Boening, Paul H. Larsen, Vadar F. |
Date of Original | 1982 |
Conference Title | Proceedings of the 37th Industrial Waste Conference |
Extent of Original | p. 295-304 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University LIbraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-07-14 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 295 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | ANAEROBIC FLUIDIZED BED WHEY TREATMENT Paul H. Boening, Visiting Assistant Professor Department of Civil Engineering State University of New York at Buffalo Buffalo, New York 14260 Vadar F. Larsen, Professor Department of Biotechnology Massey University Palmerston North, New Zealand Anaerobic processes have several advantages over aerobic processes for waste treatment. The main advantage is that anaerobic processes are energy producing, while aerobic processes are energy consuming. Anaerobic processes also have the advantage of producing lower quantities of biological solids for final disposal. The major disadvantage of anaerobic processes has been the longer hydraulic retention time required for treatment. Fixed film reactors offer a solution to the problem of long hydraulic retention times and avoid the solids separation problems associated with the anaerobic contact process. Anaerobic filters have been extensively studied after the initial work by Young and McCarty [ 1 ] and have been modified to give the characteristics of a completely mixed system by De- Walle and Chian [2). Fluidized reactors have been evaluated both for aerobic and denitrification processes [3,4] and anaerobic processes [5]. This type of reactor offers advantages over other fixed film reactors. Fluidized bed reactors have much larger specific surface areas which allows increased concentrations of microorganisms. Larger specific surface area allows shorter hydraulic retention time for the same amount of treatment or it allows the use of lower operating temperatures. Specific surface areas of 80 m2/m3 have been reported for trickling filters and 160 m2/m3 for rotating biological contactors [61. A specific surface area of 206 m2/m3 has been reported for an anaerobic filter [2] while a specific surface area of 3000 m*/m3 has been reported for a fluidized bed reactor [3]. Concentrations of microorganism of 40 g/1 are possible in denitrification processes [6) and over 30 g/1 have been measured in anaerobic processes [5]. Packed bed reactors such as anaerobic filters often experience problems of increased pressure drop due to the accumulation of biomass. To prevent plugging relatively large voidage must be maintained which limits specific surface area and biomass concentration. Fluidized bed reactors overcome these problems allowing the use of low-voidage, high-surface-area media [7]. Also, influent suspended solids are not a problem and bed material may be easily added or removed. Tapered beds offer the additional advantage of greater stability over a large range of flowrates [8J. Previous anaerobic work with fluidized bed reactors was performed on dilute waste of COD values up to 600 mg/l. Waste stabilization efficiency up to 80% was obtained at a 3 hour hydraulic detention time [5]. This chapter presents work conducted to demonstrate the potential of and evaluate kinetic coefficients, for anaerobic fluidized bed treatment of moderately strong whey wastes of 2000-7000 mg/l COD. MATERIALS AND METHODS Two fluidized bed reactors were used in this work. Reactor number one (Figure 1) was a tapered bed with a 0.095-m diameter at the top and an inlet diameter of 3.2 x 295 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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