Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters

M. T. Kato, James A Field, P. Versteeg, G. Lettinga

Research output: Contribution to journalArticle

94 Citations (Scopus)

Abstract

The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was Investigated in laboratory-scale reactors at 30°C. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to 12 g COD/L.d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGSB reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L.d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up. the operation should be limited to an organic loading rate of 7 g COD/L.d and to a liquid upflow velocity between 2.5 and 5.5 m/h.

Original languageEnglish (US)
Pages (from-to)469-479
Number of pages11
JournalBiotechnology and Bioengineering
Volume44
Issue number4
DOIs
StatePublished - Aug 5 1994
Externally publishedYes

Fingerprint

Chemical oxygen demand
Waste Water
Sewage
Biological Oxygen Demand Analysis
Wastewater
Liquids
Biofuels
Degassing
Biogas
Substrates
Dissolved oxygen
Flotation
Buoyancy
Pistons
Contacts (fluid mechanics)
Biomass
Ethanol
Gases
Hydraulics
Oxygen

Keywords

  • Anaerobic treatment
  • Dissolved oxygen
  • Granular sludge bed
  • Sludge hold-up
  • Wastewater, low-strength soluble

ASJC Scopus subject areas

  • Biotechnology
  • Microbiology

Cite this

Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters. / Kato, M. T.; Field, James A; Versteeg, P.; Lettinga, G.

In: Biotechnology and Bioengineering, Vol. 44, No. 4, 05.08.1994, p. 469-479.

Research output: Contribution to journalArticle

@article{38640329f42f46fca6a8e00493177b2e,
title = "Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters",
abstract = "The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was Investigated in laboratory-scale reactors at 30°C. Chemical oxygen demand (COD) removal efficiency was above 80{\%} at organic loading rates up to 12 g COD/L.d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGSB reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L.d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up. the operation should be limited to an organic loading rate of 7 g COD/L.d and to a liquid upflow velocity between 2.5 and 5.5 m/h.",
keywords = "Anaerobic treatment, Dissolved oxygen, Granular sludge bed, Sludge hold-up, Wastewater, low-strength soluble",
author = "Kato, {M. T.} and Field, {James A} and P. Versteeg and G. Lettinga",
year = "1994",
month = "8",
day = "5",
doi = "10.1002/bit.260440410",
language = "English (US)",
volume = "44",
pages = "469--479",
journal = "Biotechnology and Bioengineering",
issn = "0006-3592",
publisher = "Wiley-VCH Verlag",
number = "4",

}

TY - JOUR

T1 - Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters

AU - Kato, M. T.

AU - Field, James A

AU - Versteeg, P.

AU - Lettinga, G.

PY - 1994/8/5

Y1 - 1994/8/5

N2 - The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was Investigated in laboratory-scale reactors at 30°C. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to 12 g COD/L.d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGSB reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L.d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up. the operation should be limited to an organic loading rate of 7 g COD/L.d and to a liquid upflow velocity between 2.5 and 5.5 m/h.

AB - The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was Investigated in laboratory-scale reactors at 30°C. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to 12 g COD/L.d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGSB reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L.d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up. the operation should be limited to an organic loading rate of 7 g COD/L.d and to a liquid upflow velocity between 2.5 and 5.5 m/h.

KW - Anaerobic treatment

KW - Dissolved oxygen

KW - Granular sludge bed

KW - Sludge hold-up

KW - Wastewater, low-strength soluble

UR - http://www.scopus.com/inward/record.url?scp=0028765380&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028765380&partnerID=8YFLogxK

U2 - 10.1002/bit.260440410

DO - 10.1002/bit.260440410

M3 - Article

VL - 44

SP - 469

EP - 479

JO - Biotechnology and Bioengineering

JF - Biotechnology and Bioengineering

SN - 0006-3592

IS - 4

ER -