Adapting high-rate anaerobic treatment to Middle East conditions

N.A. Mahmoud; G. Zeeman; J.B. van Lier

doi:10.1007/978-3-540-74492-4_13

Adapting high-rate anaerobic treatment to Middle East conditions

N.A. Mahmoud, G. Zeeman, J.B. van Lier

Research output: Chapter in Book/Report/Conference proceeding › Chapter › Academic › peer-review

Abstract

High-rate anaerobic technologies offer cost-effective solutions for sewage treatment in the Middle East and Palestine in particular. The sewage characteristics in Palestine are quite different from the values elsewhere and show solids contents of more than 1000 mg chemical oxygen demand (COD)ss/L and total COD values exceeding 2000 mg/L. While summer temperatures exceed 25 °C, temperatures may drop to below 15 °C in winter. Simple model calculations indicate that conventional upflow anaerobic sludge bed (UASB) reactor should be dimensioned on hydraulic retention times (HRTs) approaching 1 day to ensure methanogenic conditions in all seasons. Consequently, reactor volumes are three times the size of similar reactors in the tropics while the feasibility of the hydraulic flow patterns at such reduced rate are questionable. In an alternative approach, the UASB reactor was amended by incorporating a parallel digester unit for enhanced sludge stabilization and generation of active methanogenic sludge to be recirculated to the UASB reactor. The digester operational conditions were assessed by operating eight completely stirred tank reactors (CSTRs) fed with primary sludge. The results showed a high degree of sludge stabilization in the parallel digesters at a solids retention time of ¿10 and 15 days at process temperatures of 35 and 25 °C, respectively. The technical feasibility of the UASB-Digester combination was demonstrated by continuous flow pilot-scale experiments. A pilot UASB reactor was operated for 81 days at six hours HRT and 15 °C and was fed with raw domestic sewage. This period was subsequently followed by an 83 days operation period incorporating a parallel digester unit, which was operated at 35 °C. The UASB-Digester combination achieved removal efficiencies of total, suspended, colloidal and dissolved CODs of 66, 87, 44 and 30%, respectively. Preliminary model calculations indicated that a total reactor volume (UASB-Digester) corresponding to 8.6 hours hydraulic retention time (HRT) might suffice for sewage treatment in Palestine

Original language	English
Title of host publication	Efficient Management of Wastewater, Its Treatment and Reuse in Water Scarce Countries
Editors	I. Al Baz, R. Otterpohl, C. Wendland
Place of Publication	Heidelberg, Germany
Publisher	Springer
Pages	150-160
ISBN (Print)	9783540744917
DOIs	https://doi.org/10.1007/978-3-540-74492-4_13
Publication status	Published - 2008

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10.1007/978-3-540-74492-4_13

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title = "Adapting high-rate anaerobic treatment to Middle East conditions",

abstract = "High-rate anaerobic technologies offer cost-effective solutions for sewage treatment in the Middle East and Palestine in particular. The sewage characteristics in Palestine are quite different from the values elsewhere and show solids contents of more than 1000 mg chemical oxygen demand (COD)ss/L and total COD values exceeding 2000 mg/L. While summer temperatures exceed 25 °C, temperatures may drop to below 15 °C in winter. Simple model calculations indicate that conventional upflow anaerobic sludge bed (UASB) reactor should be dimensioned on hydraulic retention times (HRTs) approaching 1 day to ensure methanogenic conditions in all seasons. Consequently, reactor volumes are three times the size of similar reactors in the tropics while the feasibility of the hydraulic flow patterns at such reduced rate are questionable. In an alternative approach, the UASB reactor was amended by incorporating a parallel digester unit for enhanced sludge stabilization and generation of active methanogenic sludge to be recirculated to the UASB reactor. The digester operational conditions were assessed by operating eight completely stirred tank reactors (CSTRs) fed with primary sludge. The results showed a high degree of sludge stabilization in the parallel digesters at a solids retention time of ¿10 and 15 days at process temperatures of 35 and 25 °C, respectively. The technical feasibility of the UASB-Digester combination was demonstrated by continuous flow pilot-scale experiments. A pilot UASB reactor was operated for 81 days at six hours HRT and 15 °C and was fed with raw domestic sewage. This period was subsequently followed by an 83 days operation period incorporating a parallel digester unit, which was operated at 35 °C. The UASB-Digester combination achieved removal efficiencies of total, suspended, colloidal and dissolved CODs of 66, 87, 44 and 30%, respectively. Preliminary model calculations indicated that a total reactor volume (UASB-Digester) corresponding to 8.6 hours hydraulic retention time (HRT) might suffice for sewage treatment in Palestine",

author = "N.A. Mahmoud and G. Zeeman and {van Lier}, J.B.",

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doi = "10.1007/978-3-540-74492-4_13",

language = "English",

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pages = "150--160",

editor = "{Al Baz}, I. and R. Otterpohl and C. Wendland",

booktitle = "Efficient Management of Wastewater, Its Treatment and Reuse in Water Scarce Countries",

publisher = "Springer",

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}

Adapting high-rate anaerobic treatment to Middle East conditions. / Mahmoud, N.A.; Zeeman, G.; van Lier, J.B.
Efficient Management of Wastewater, Its Treatment and Reuse in Water Scarce Countries. ed. / I. Al Baz; R. Otterpohl; C. Wendland. Heidelberg, Germany: Springer, 2008. p. 150-160.

Research output: Chapter in Book/Report/Conference proceeding › Chapter › Academic › peer-review

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T1 - Adapting high-rate anaerobic treatment to Middle East conditions

AU - Mahmoud, N.A.

AU - Zeeman, G.

AU - van Lier, J.B.

PY - 2008

Y1 - 2008

N2 - High-rate anaerobic technologies offer cost-effective solutions for sewage treatment in the Middle East and Palestine in particular. The sewage characteristics in Palestine are quite different from the values elsewhere and show solids contents of more than 1000 mg chemical oxygen demand (COD)ss/L and total COD values exceeding 2000 mg/L. While summer temperatures exceed 25 °C, temperatures may drop to below 15 °C in winter. Simple model calculations indicate that conventional upflow anaerobic sludge bed (UASB) reactor should be dimensioned on hydraulic retention times (HRTs) approaching 1 day to ensure methanogenic conditions in all seasons. Consequently, reactor volumes are three times the size of similar reactors in the tropics while the feasibility of the hydraulic flow patterns at such reduced rate are questionable. In an alternative approach, the UASB reactor was amended by incorporating a parallel digester unit for enhanced sludge stabilization and generation of active methanogenic sludge to be recirculated to the UASB reactor. The digester operational conditions were assessed by operating eight completely stirred tank reactors (CSTRs) fed with primary sludge. The results showed a high degree of sludge stabilization in the parallel digesters at a solids retention time of ¿10 and 15 days at process temperatures of 35 and 25 °C, respectively. The technical feasibility of the UASB-Digester combination was demonstrated by continuous flow pilot-scale experiments. A pilot UASB reactor was operated for 81 days at six hours HRT and 15 °C and was fed with raw domestic sewage. This period was subsequently followed by an 83 days operation period incorporating a parallel digester unit, which was operated at 35 °C. The UASB-Digester combination achieved removal efficiencies of total, suspended, colloidal and dissolved CODs of 66, 87, 44 and 30%, respectively. Preliminary model calculations indicated that a total reactor volume (UASB-Digester) corresponding to 8.6 hours hydraulic retention time (HRT) might suffice for sewage treatment in Palestine

AB - High-rate anaerobic technologies offer cost-effective solutions for sewage treatment in the Middle East and Palestine in particular. The sewage characteristics in Palestine are quite different from the values elsewhere and show solids contents of more than 1000 mg chemical oxygen demand (COD)ss/L and total COD values exceeding 2000 mg/L. While summer temperatures exceed 25 °C, temperatures may drop to below 15 °C in winter. Simple model calculations indicate that conventional upflow anaerobic sludge bed (UASB) reactor should be dimensioned on hydraulic retention times (HRTs) approaching 1 day to ensure methanogenic conditions in all seasons. Consequently, reactor volumes are three times the size of similar reactors in the tropics while the feasibility of the hydraulic flow patterns at such reduced rate are questionable. In an alternative approach, the UASB reactor was amended by incorporating a parallel digester unit for enhanced sludge stabilization and generation of active methanogenic sludge to be recirculated to the UASB reactor. The digester operational conditions were assessed by operating eight completely stirred tank reactors (CSTRs) fed with primary sludge. The results showed a high degree of sludge stabilization in the parallel digesters at a solids retention time of ¿10 and 15 days at process temperatures of 35 and 25 °C, respectively. The technical feasibility of the UASB-Digester combination was demonstrated by continuous flow pilot-scale experiments. A pilot UASB reactor was operated for 81 days at six hours HRT and 15 °C and was fed with raw domestic sewage. This period was subsequently followed by an 83 days operation period incorporating a parallel digester unit, which was operated at 35 °C. The UASB-Digester combination achieved removal efficiencies of total, suspended, colloidal and dissolved CODs of 66, 87, 44 and 30%, respectively. Preliminary model calculations indicated that a total reactor volume (UASB-Digester) corresponding to 8.6 hours hydraulic retention time (HRT) might suffice for sewage treatment in Palestine

U2 - 10.1007/978-3-540-74492-4_13

DO - 10.1007/978-3-540-74492-4_13

M3 - Chapter

SN - 9783540744917

SP - 150

EP - 160

BT - Efficient Management of Wastewater, Its Treatment and Reuse in Water Scarce Countries

A2 - Al Baz, I.

A2 - Otterpohl, R.

A2 - Wendland, C.

PB - Springer

CY - Heidelberg, Germany

ER -

Adapting high-rate anaerobic treatment to Middle East conditions

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