MEMORANDUM

TO: Brian D’Amico, USEPA/OW/OST/EAD

FROM: Cortney Itle, ERG

DATE: August 31, 2010

SUBJECT: Summary of Anaerobic Flui dized Bed Applications

Anaerobic Fluidized Beds (AFBs) are a type of re actor that can be used to complete multiphase chemical reactions. In these reactors, granular su bstrates are fluidized by the flow of liquids or gas through the system. Historically, AFBs have been used in the petroleum industry to process petroleum. However, AFBs are becoming more commonly us ed to biologically treat wastewaters. AFBs have advantages over other anaerobic treatment systems because they have larger surface areas for biological treatment. This allows AFBs to treat higher strength wastes and have shorter treatment times than other systems. In addition, AFBs are less likely to clog or retain sludge and they have smaller volume and area requirements compared to other systems.

AFBs have been successful in treating many differe nt types of wastewaters. The purpose of this memorandum is to provide a brief overview of exam ples of the applications of AFBs. A select number of journal articles were reviewed that discussed various uses of AFBs. An exhaustive literature review was not performed; this memora ndum does not provide a complete list of all of the potential applications of AFBs and instea d provides a brief overview of a few selected applications.

The articles reviewed include:

 Borja and Banks (1995)

.

 Garcia-Calderon, et al. (1998)

 Haroun and Idris ( 2009)

 Heijnen, et al. (1989)

 Sowmeyan and Swaminathan (2008)

 Toldra, et al. (1987)

Full citations of the articles are provided in the re ference list. Brief descri ptions of the articles

are included below.

Borja and Banks (1995)

The Borja and Banks study reviewed the effectiv eness of AFB to treat ice cream wastewater, which is a complex mixture including milk prot eins, carbohydrates, and li pids. Because of the high lipid content and ch emical oxygen demand (COD), off site disposal of the wastewater has proven to be difficult and expensive. Previous st udies have shown that other anaerobic treatment systems can be effective treatment methods for th ese wastewaters. The purpose of this study wasMemorandum August 31, 2010 Page 2 of 4

to document the efficiency of AFB and to determ ine the effects of changi ng parameters (influent COD, temperature, etc) on the reactor effluent . The wastewater was treated in a bench scale

reactor. The reactor was able to remove C OD up to 94 percent with COD loading rates of 15.6 grams per liter per day.

Garcia-Calderon, et al. (1998)

Wastewater from a red wine distillery was tr eated in a downflow AFB in the Garcia-Calderon study. A bench scale AFB reactor which included pe rlite as the fluidized substrate was used in this study. The reactor achieved 85 percent removal of total organic carbon (TOC) removal, at an organic loading rate of 4.5 kg TOC per m 3 per day.

Haroun and Idris ( 2009)

Textile wastewater has high COD, biochemical oxygen demand (BOD), and color. Haroun and Idris investigated the effects of varying hydraulic retention time s (HRTs), organic loading rates (OLRs), and amounts of supplemented glucose (a n external carbon source) on the removal of COD, BOD, and color from textil e wastewater. The study determin ed that the most efficient system included the addition of 600 mg/l glucose. This system was able to achieve a 98 percent

reduction in soluble COD on a load ing rate of 4.4 kg COD per m 3 per day.

Heijnen, et al. (1989)

Heijnen et al. provided an overview of the app lication of AFBs in wastewater treatment by providing a historical summary of AFB development and research. The article states that the understanding of AFB treatment progressed in th e 1980’s, and historic di sadvantages of AFBs have been overcome. A summary table of research articles is provided th at lists the type of

waste treated and the characterist ics of the systems and treatment achieved for each article. In addition, summaries of several full scale systems ar e provided that treat soft drink wastewater plant, a soy protein fact ory, and a yeast factory.

Sowmeyan and Swaminathan (2008)

Sowmeyan and Swaminathan researched the abil ity of a downflow AFB to treat distillery wastewater with varying HRTs and OLRs. A bench scale react or was constructed and fed a synthetic wastewater that was given the characte ristics of distillery waste. The AFB was found to be adaptable to different HRTs and OLRs and it maintained a removal of approximately 84 percent of COD with OLRs of up to 35 kg COD per m 3 per day.

Toldra, et al. (1987)

Toldra et al. used 3 bench scale AFB reactors to treat wastewater from a hog slaughterhouse, a dairy processing plant, and a br ewery. The different types of wastewater exhibited different treatment characteristics depending on temper ature and OLR. For slaughterhouse waste, 75 percent of soluble COD was removed with infl uent concentrations of 430-850 mg/L COD.Memorandum August 31, 2010 Page 3 of 4

Dairy waste with 200-500 mg/L COD was treated to 80 percent of soluble COD removal. Brewery waste achieved 50 percent removal of soluble COD with influents of 860-2500 mg/L

COD.

Table 1 presents a summary of the articles reviewe d, including the type of waste, the scale of the system, the strength of the waste, and the removal of the system.

Table 1. Summary of AFB Articles Reviewed

Reference Type of Waste Scale of system Strength of waste Removal Borja and Banks

1995 Ice cream Bench scale 5.2 g/l 94% COD

Garcia-Calderon et

al. 1998 Distillery Bench scale 5.5 to 6.5 kg/m TOC 4.5 kg TOC/m3-day 11.3 kg COD/m3/day 85% TOC

Haroun and Idris

2009 Textile Bench scale 2200 mg/L COD 4.4 kg COD/m3/day 98% soluble COD

Heijnen et al.1989 Multiple Multiple Multiple Multiple Sowmeyan and

Swaminathan 2008 Distillery Bench scale 35 kg COD/m3-day 84% COD

Toldra et al.1987 Slaughterhouse Dairy Brewery Bench scale 430-850

200-500

860-2500 mg/L COD 75%

80%

50%

soluble CODMemorandum August 31, 2010 Page 4 of 4

References

Borja, Rafael and Charles J. Banks. Response of an anaerobic fluidized bed reactor treating icecream wastewater to organic, hydr aulic, temperature and pH shocks. Journal of Biotechnology, 1995, Volume 39, Pages 251-259.

Garcia-Calderon, D. and P. Buffiere, R. Mole tta, S. Elmaleh. Anaerobic digestion of wine distillery wastewater in down-flow fluidized bed. Water Research, Volume 32, Issue 12, December 1998, Pages 3593-3600.

Haroun, Mahdi and Azni Idris. Treatment of tex tile wastewater with an anaerobic fluidized bed

reactor. Desalination, Volume 237, Issues 1-3, February 2009, Pages 357-366.

Heijnen, J.J. and A. Mulder, W. Enger, F. Hoeks. Review on the application of anaerobic

fluidized bed reactors in waste-water treatment. The Chemical Engineering Journal, Volume 41, Issue 3, September 1989, Pages B37-B50.

Sowmeyan, R. and G. Swaminathan. Evaluation of inverse anaerobic fluidized bed reactor for treating high strength organic wastewater. Bioresource Technology, Volume 99, Issue 9, June 2008, Pages 3877-3880.

Toldra, F. and A. Flors, J. L. Lequerica, S. Valles. Fluidized bed anaer obic biodegradation of food industry wastewaters. Biological Wastes, Volume 21, Issue 1, 1987, Pages 55-61.