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Upflow anaerobic sludge blanket (UASB)

Fixed Bed Anaerobic Digestion system (with CH4 capturing capability: 0.56 m3biogas/kg COD degraded or 15,400 m3 CH4/day)

The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during

5 days of incubation at 20 C

The BOD5 test

There are two commonly recognized methods for the measurement of BOD.

[edit]Dilution method

To ensure that all other conditions are equal a very small amount of micro-organism seed is added to

each sample being tested. This seed is typically generated by diluting organismswithbuffered dilution

water. The BOD test is carried out by diluting the sample with oxygen saturated dilution water, inoculating

it with a fixed aliquot of seed, measuring thedissolved oxygen(DO) and then sealing the sample to

prevent further oxygen dissolving in. The sample is kept at 20 C in the dark to

preventphotosynthesis(and thereby the addition of oxygen) for five days, and the dissolved oxygen is

measured again. The difference between the final DO and initial DO is the BOD.

The loss of dissolved oxygen in the sample, once corrections have been made for the degree of dilution,

is called the BOD5. For measurement ofcarbonaceous BOD (cBOD), a nitrification inhibitor is added

after the dilution water has been added to the sample. The inhibitor hinders theoxidationof ammonia

nitrogen.

BOD can be calculated by:

Undiluted: Initial DO - Final DO = BOD

Diluted: ((Initial DO - Final DO)- BOD of Seed) x Dilution Factor

BOD is similar in function tochemical oxygen demand(COD), in that both measure the amount oforganic

compoundsin water. However, COD is less specific, since it measures everything that can be chemically

oxidized, rather than just levels of biologically active organic matter.

[edit]Manometric method

This method is limited to the measurement of the oxygen consumption due only to carbonaceous

oxidation.Ammoniaoxidation is inhibited.

The sample is kept in a sealed container fitted with a pressure sensor. A substance that absorbscarbondioxide(typicallylithium hydroxide) is added in the container above the sample level. The sample is

stored in conditions identical to the dilution method. Oxygen is consumed and, as ammonia oxidation is

inhibited, carbon dioxide is released. The total amount of gas, and thus the pressure, decreases because

carbon dioxide is absorbed. From the drop of pressure, the sensor electronics computes and displays the

consumed quantity of oxygen.

The main advantages of this method compared to the dilution method are:

http://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=3http://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=3http://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=3http://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/w/index.php?title=Buffered_dilution_water&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Buffered_dilution_water&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Buffered_dilution_water&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Buffered_dilution_water&action=edit&redlink=1http://en.wikipedia.org/wiki/Oxygenation_(environmental)http://en.wikipedia.org/wiki/Oxygenation_(environmental)http://en.wikipedia.org/wiki/Oxygenation_(environmental)http://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Chemical_oxygen_demandhttp://en.wikipedia.org/wiki/Chemical_oxygen_demandhttp://en.wikipedia.org/wiki/Chemical_oxygen_demandhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=4http://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=4http://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=4http://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Pressure_sensorhttp://en.wikipedia.org/wiki/Pressure_sensorhttp://en.wikipedia.org/wiki/Pressure_sensorhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Lithium_hydroxidehttp://en.wikipedia.org/wiki/Lithium_hydroxidehttp://en.wikipedia.org/wiki/Lithium_hydroxidehttp://en.wikipedia.org/wiki/Lithium_hydroxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Pressure_sensorhttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=4http://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Chemical_oxygen_demandhttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Oxygenation_(environmental)http://en.wikipedia.org/w/index.php?title=Buffered_dilution_water&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Buffered_dilution_water&action=edit&redlink=1http://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/w/index.php?title=Biochemical_oxygen_demand&action=edit&section=3

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simplicity: no dilution of sample required, no seeding, no blank sample.

direct reading of BOD value.

continuous display of BOD value at the current incubation time.

In anaerobic digestion of POME methanogenesis is the rate limiting step.

Mempercepat dengan molase

Mill Capacity : 60 ton/hour FFB or 230,000 ton/yearPOME flowrate : 0.65 ton/year FFB or average 498 m3/dayPOME Characteristic : pH 4.1(Industrial Standards) BOD 27.000 mg/L

COD 54,500 mg/LTS 43,800 mg/LSS 19,000 mg/lO&G 8,370 mg/LNH3-N 35 mg/LTN 770 mg/l

Treatment Parameters : BOD 27,000 mg/L

COD 54,500 mg/LEffluent from Digester : BOD (total) < 1,350 mg/L (~95% removal)

BOD (dissolved):

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Parameters Value UnitFFB received 432,000 t/year

CPO yield 0.22 tonsCPO /tonsFFB

POME yield in the CPO

production

3.86 m3-POME/tonsCPO

Biogas yield from POME 16.8 m3-Biogas/m3-POME

CH4 fraction in biogas 0.62 m3- CH4/m3-Biogas

CH4 density 0.00071 tonsCH4/ m3-CH4

GWP CH4 21

Elements Formula Concentration (Vol. %)

Methane CH4 50-75

Carbon dioxide CO2 25-45

Minyak sawit

LCFA +gliserol

SCFA dan Alkohol

Metana + CO2

1. Hidrolisis minyak + 3H2O 3 LCFA+

gliserol

2.Fermentasi (C6H12O6)n + nH2O CH3CHOHCOOH

Glukosa Asam LaktatCH3CH2CH2COOH + CO2 + H2

Asam Butirat

CH3CH2OH + CO2

Etanol

4H2 + CO2 2H2O + CH4CH3CH2OH + CO2 CH3COOH + CH4

CH3COOH + CO2 CO2 + CH4

CH3CH2CH2COOH + 2H2 + CO2 CH3COOH + CH4Metan

3. Metanogenik

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Water vapour H2O 2-7

Oxygen O2 < 2

Nitrogen N2 < 2

Hydrogen sulphide H2S < 2

Ammonia NH3 < 1

Hydrogen H2 < 1

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Terbentuknya biogasKomponen biogas yang paling penting adalah gas methan,

selain itu juga gas-gas lain yang dihasilkan dalam ruangan yang

disebut digester. Biogas yang dihasilkan oleh biodigester

sebagian besar terdiri dari 54% 70% metana (CH4), 27 45%

karbondioksida (CO2), 3%-5% nitrogen (N2), 1%-0% hidrogen

(H2), 0,1% karbon monoksida (CO), 0,1% oksigen (O2) dan

sedikit hidrogen sulfida (H2S)

Ada tiga kelompok bakteri yang berperan dalam proses

pembentukan biogas:

1. Kelompok bakteri fermentatif, yaitu : Steptococci,

Bacteriodes, dan beberapa jenis Enterobactericeae,

2. Kelompok bakteri asetogenik, yaitu Desulfovibrio,

3. Kelompok bakteri metana, yaitu Mathanobacterium,

Mathanobacillus, Methanosacaria, dan Methanococcus

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