Biochemical methane potential applied to solid wastes -...

M. T. Santos, Cyprus 2016

Biochemical methane

potential applied to solid

wastes - review

T. M. Cabrita1, M. T. Santos1, A. M. Barreiros1

1 ADEQ, Instituto Superior de Engenharia de Lisboa - ISEL/IPL.

M. T. Santos, Cyprus 2016 2

Contents

• Introduction

• Goals

• BMP publications

• BMP methods

• Factors affecting BMP tests

• BMP applied to solid substrates

• BMP conditions and results

• Conclusions

• Future work


Introduction

• Anaerobic digestion (AD) is a widely applied technology to treatsolid wastes and produce biogas

• In Europe, exist around of 120 full-scale plants to AD municipal solidwastes.

Central Sewage Sludge Treatment Plant Bottrop

http://blogs.qub.ac.uk/atbest/page/2/http://www.adp.pt/pt/sustentabilidade/inovacao-e-desenvolvimento---conheca-os-projetos-em-curso/?id=37


Introduction

• In Portugal (2013) biogas come from landfills (96 %), wastewatertreatment plants and solid waste treatment plants

• Represent 1 % of the renewable sources

Tratolixo, E.I.M.S.A. Valorsul, S. A.


Introduction

AD - optimization

How to increase the biogas production ?

Wastes from several sources or mixtures

BMP – Biochemical methane potential

• To obtain the biodegradability of different substrates ormixture of substrates;

• To choose potential substrates to anaerobic digestion

most widely used technique


Introduction

What is BMP test ?

Batch test

Substrates

Syringe

Rubber

ReactorInoculum


Present and evaluate the BMP factors, methodologies, solid organic substrates and results

Goal

• Substrate

BMP publications

How to do BMP test ?

• Inoculum • Methodology

With or withoutpre-treatment

SourceAmount

Operational conditionsGas measurement conditions


BMP publications

• Publications between 2008 and 2015 - keywords “anaerobic digestion” and “BMP”• Survey - Online Knowledge Library (B-on) with peer-reviewed publications.

*Results up until the end of April

0

100

200

300

400

500

2008 2009 2010 2011 2012 2013 2014 2015 2016

AD

-BM

P -p

ublic

atio

ns

*

How much interest exists for BMP?

• From 100 to almost 500

• Great amount of databiodegradabilitycomparison fromdifferent solid wastesstill problematic


BMP methods

• Owen et al. (1979) presents the most popular method for BMPin the last 3 decades. Still used with modifications (e.g. volumereactor, inoculum source and concentration);

• Chynoweth et al. (1993) analysed the influence of 3 factors:inoculum source, inoculum/substrate ratio (I/S) and particlesize – inoculum active, I/S 2, particle size > 1 mm;

• Owens & Chynoweth (1993) also modified the Owen et al.(1979) methodology – substrate 2 g VS/L, medium withdifferent mineral concentrations and inoculum (fed of 1.6 gVS/L), bottles 275 mL (100 mL of inoculum);


BMP methods

• Angelidaki and Ahring (1993) referred the need to acclimate theinoculum to specific conditions like the ammoniaconcentration;

• Angelidaki and Ahring (1997) - bottles of 117 mL with 20 mL ofan adapted inoculum;

• Hansen et al. (2004) adapted and modified - bottles of 2 L(400 mL de inoculum and 100 mL of sample);


BMP methods

• Angelidaki and Sanders (2004) - a substantial uncertainty inBMP – AD is a complex process. Different units, e.g. L CH4/kg-waste, L CH4/L-waste, L CH4/kg-VS added or L CH4/kg-CODadded (P = 1 atm and T = 0 ºC);

• Angelidaki et al. (2009) - guidelines and advices for severalfactors - substrate, inoculum source, inoculum activity,medium blank and controls, replicates, mixing, datacollection, bottles volume (0.1 to 2 L), interpretation andreporting conditions;

• Other methods: technical guideline VDI 4630 (2006) and ISOguideline 11734 (1995).


Factors affecting BMP tests

ExperimentalConditions

Gas Measurement Systems

Volumetric methods

Manometric methods

GC

OperationalConditions

Physical

Reactor capacity

Temperature

Stirring

Incubation time

Chemical

Headspace gas

pH and alkalinity

Mineral mediumI/S ratio


BMP applied to solid substrates

• Approximately 70 different substrates (around 80 references)submitted to BMP tests;

• Solids contents expressed in different units such as g/L, g/kg, %,mg/L and in wet base;

• Total solids (TS) contents represented in: Percentage - 0.7 to almost 100 %; g/kg units - 47.3 to 991 g/kg; g/L - 3.97 to 331.33 g/L;

• Volatile solids (VS) contents presented in different bases, e.g.related with TS, dry mass and wet weight.


BMP applied to solid substrates

Substrate TS VS Reference

Brewery grain waste 24.2 % 23.0 % Kafle et al. 2013

Food waste 48,400 ± 2,700 mg/L 27,900 ± 1,300 mg/L Elbeshbishy et al. 2012

Organic fraction of

municipal solid waste461 g/kg 386 g/kg Nielfa et al. 2015

Two-phase olive mill

solid waste265 ± 3 g/kg 228 ± 2 g/kg Rincón et al. 2016

Livestock residues on-

farm42-45 wt%, wet basis 31-35 wt%, wet basis Yap et al. 2016

Secondary sewage

sludge from WWTP19.05 ± 1.21 g/L 13.99 ± 1.05 g/L

Abelleira-Pereira et al.

2015

Source-separated

organic household waste24-86 % ww 81-94 % TS Naroznova et al. 2016

Examples of solid substrates and solids contents


BMP conditions and results

• Several items were analysed (2011 to 2016): inoculum and substratesources, pre-treatment, reactor volume, headspace, I/S ratio,temperature, incubation time and measurement of biogas;

Reference Inoculum source Pre-treatment Reactor

(mL) I/S T (°C)

Incubation time (d)

Biogas Production

Apples et al. 2011 Digested sludge na 1,000 100

g/500 g MC 21 25-456.3 mL CH4/g ODM

Fernández-Cegrí et al. 2012 GS Chemical and

TC (75 ⁰C) 250 (EV) 2 VS/2.5 COD 35 7-10 0-273 mL CH4

/gCODadded

Ruggeri et al. 2015 CM NaOH, Salts, US, US+salts 250 na 30 App. 60 2-193 L CH4

/kgVS0

Naroznova et al. 2016

Collected from a WWTP na 1,000 2 VS 37 45

202-572 mL CH4/g

VSsubtrate

Examples of solid substrates and solids contents

na: not availableCM – Cattle manure; COD – Chemical oxygen demand; EV – Effective volume; GS – Granular sludge; MC – Mesophilic conditions; ODM – Organic drymatter; T – Temperature; TC – Thermochemical; US – Ultrasonic; VS – Volatile solids; WWTP – Wastewater treatment plant


BMP experimental conditions and results

Author Substrate origin Inoculum origin PretreatmentReactor

(mL)

Headspace volume

(ml)

Number of replicates I/S

Temperature (°C) Mixing rate

Incubation time (d) Measurement of biogas Biogas Production

Standard Conditions

Lalabut et al. 2011

Raw manures; Food residues; Invasive aquatic plants; Others (switchgrass, corn silage, corn

leachate, mouthwash, suspended FOG and settled FOG).

farm-based completely mixed anaerobic digester - 250 35 manual 40

cumulative pressure - pressure transducers

106.5-648.5 mL CH4/g VSadded

stp

Luna-delRisco

et al. 2011

Grass silage, maize silage, different mix silages (grasses and legumes, mix rate is not specified),

cow slurry, pig slurry, fermentation slops and grain mill

residues.

Anaerobic reactor of a WWTP - 575 375 triplicate 150 ml / 0.3 g TS 36

regularly once a day, manually 48-72

increase in pressure in the gas phase of test bottles using an absolute

pressure transducer. GC

Agricultural Substrates: 238-319 L CH4.kgVS-1

added; Food Industry Wastes: 335-

714 L CH4.kgVS-1added;

Cereal Industry Residues:

272-384 L CH4.kgVS-1added

0°C and 1 atm (stp)

Lesteur et al. 2011

MSW - cardboard, rice, rusk, potatoes, papers, vegetables,

bread and a waste built by mixing some of the simple wastes) and

lignocellulosic green wastes

active anaerobic sludge - 600 duplicate 0.5 35 35 every two days with Micro-GC

MSW (graphical analysis): 87-355 mL CH4.g-1 VS; Raw

samples: 20-400 mL CH4.g-1

VS

Apples et al. 2011

thickened sludge samples were collected from different WWTPs

Digested sludge originating from the

fullscale digester located at the WWTP

- 1000 triplicate 100 g I/500 g S mesophilic conditions

21 displacement of the liquid in the cylinders. GC-TCD

25-456.3 mL CH4/g ODM

Val del Rio et al.

2011aerobic granular sludge Thermal (60-210 °C) 570 170 1 g VS/VS 35 120 rpm 26

variation of pressure inside the glass flask by means of a pressure

transducer and GC169-404 mL-CH4/g-VSfed

Nieto et al. 2012

wastes from three agro-food industries (dairy, cider production,

cattle farming)

Anaerobic sludge from a municipal WWTP - 2,000 1,400 duplicate

0.67, 1, 1.33, 2 and 4.00 VS 35

continuously on a shaking-table 55

manually by apressure transmitter and GC-TCD

202-549 mL STP CH4·g

VS waste-1

STP, P=1 bar and T=0 ⁰C

Elbeshbishy et al.

2012

OFMSW and primary sludge of WWPT

1 - primary mesophilic AD at a WWTP; 2 - mesophilic

AD treating SSO , 3 -mesophilic AD treating primary and secondary

wastewater

- 260 60 triplicate0.25, 0.5, 1, 2 and 4

mass VSS/massCOD

37 180 rpm app. 28at the end of the test using

appropriately sized glass syringes in the 5–100 mL range. GC-TCD

primary sludge: 221-283 mL CH4/g VSSsub; food waste: 440-1400 mL CH4/g VSSsub

Triolo et al. 2012

Herbaceous plants that do not have a persistent woody stem and nonherbaceous material such as

hedge and tree trimmings.

Fangel biogas plant 37ºC fed with 80% animal slurry

and about 20% organic industrial waste

-1,000

(working volume)

triplicate 3:1 TS 37A couple of times during a working

day, manuallyapp. 60 VDI and GC-TCD 104-388.9 CH4 N L kg VS-1

STP conditions

(273 K, 1.013 hPa)

Fernández-Cegrí

et al. 2012

The sunflower oil cake sample used in this study was collected

from a sunflower oil factory

Granular sludge taken from an industrial anaerobic

reactor 35 ⁰C

Chemical and Thermochemical (75 ⁰C) (Ca(OH)2,

NaOH, NaHCO3 and H2SO4)

250 (effective volume)

triplicate 2 VS/2.5 COD 35 300 rpmbetween 7

and 10

flushing the gas througha 2 N NaOH solution volume

displacement0-273 mL CH4 g-1 CODadded stp

Costa et al. 2012

Chicken feather waste and poultry litter were collected from a local

poultry industry

Anaerobic suspend sludge - municipal sludge digester. Anaerobic granular sludge -

brewery industry.

Thermochemical (20-90 ⁰C) (Ca(OH)2,

NaOH)

50 (working volume)

triplicate0.66, 0.71, 0.76 and

1.32 g VS/ g VS

37 and 65 (bioaugment

ation)80 GC/FID 45-123 L CH4 kg-1 VSadded stp

Eiroa et al. 2012

Solid fish waste - tuna, sardine, mackerel and needle fish.

suspended sludge - urban wastewater treatment plant. granular sludge - brewery

industry.

triplicate

0.15–0.18, 0.30–0.36 and

0.77–0.91 g VS/g VS; 0.4, 0.77 and 1.25 g VS/g VS; 0,71 and 0.83 g

VS/g VS

37

between 60 and 80 (graphics difficult to

read)

pressure transducer. GC-FID0.04-0.35 L CH4/g VSadded; Co-digestion (tuna:gorse): 0.16-0.21 L CH4/g VSadded

stp

Lim & Fox 2013

Thickened primary and secondary sludge was obtained from a

municipal activated sludge facility.

Anaerobic granular sludge was obtained from an

UASB treating industrial waste.

- 250 100 triplicate 1/1, 1/3 and 1/8 35 21the syringe method and equilibrating

the pressure with atmospheric conditions. GC-TCD

21.93-76.27 mL CH4/g VSadded

Cavaleiro et al. 2013

Two wastes from a meat-processing plant located in

Portugal were used: (i) greaves, the residue that remains after the rendering of pig tallow, and (ii)

rinds, the tough outer covering of bacon or pig meat.

Granular sludge from a brewery wastewater

treatment plant

NaOH, NaOH+temperature, NaOH+autoclaving, temperature, Enzyme

and Autoclaving+enzyme

(25-121 ⁰C)

160 80 triplicate

4 g VS g-1

CODsoluble+colloidal

and 1.3–3.3 g VS g-

1 CODtotal; untreated: 4 g VS

g-1 CODtotal

37 150 rpm

between 50 and 110 (graphics difficult to

read)

GC 305-919 LCH4@STP kg-1

VS of the original wastestp

Risberg et al. 2013

Dry (non-treated) and steam-exploded wheat straw. Two

batches of cattle manure, both obtained from a farm

biogas plant at mesophilic temperature with source-

sorted municipal household waste and grass

silage

- 1120 420 triplicate 2 VS na na 25 and 60 GC 0.15-0.33 N L CH4/g VS

Yan et al. 2013

Dewatered sludge withdrawn from a WWTP

digested sludge withdrawn from the mesophilic

anaerobic digester in the WWTP

mild thermal (50-120 ⁰C)

3000 (working volume)

triplicate

0,0014, 0.0015, 0.0016, 0.0078,

0.013, 0.016 and 0.022 gSS/mg

COD

100 rpm 30 water displacement method67.7-144.7 mLCH4/g VSadded

(for 20 days and without the untreated)

Wall el al. 2013

grass silage; Fresh slurry - dairy farm

digestate from two digesters food waste while

and mix of poultry and cattle manure

- 500 100 triplicate 2 I/S 37 each bottle individually

30flow measurement device which

measures gas through water displacement

239-400 L CH4 kg-1 VS stp

Miao et al. 2014

algal biomass - mixture of algae bloom and lake water. Swine

manure

Swine manure. Granular sludge

- 500 100 triplicate 0.5, 1.0, 2.0 and 3.0 VS

3530 s

on and 120 s off at 46 rpm

22

Biogas produced was first passed through a scrubbing tubing filled with

the alkali solution for CO2 and H2S removal, then transported to the gas

flow meter. GC-TCD

codigestion of blue algae with swine manure: 48.2-

212.7 mL CH4 g-1 VS; blue algae inoculated with

granular sludge: 32.8-73.5 mL CH4 g-1 VS

Yoon et al. 2014 wastes from a pig slaughterhouse

Inoculum was collected from a farm-scale biogas

plant that digests piggery slurry.

- 160 100 triplicate0.67, 1, 2 and 10

VS 38 manually daily 76

daily for the first 5 days and subsequently every 2 to 3 days by displacement of an acidified brine solution in a burette, recording the volume of displaced solution after

correcting for atmospheric pressure. GC-TCD

Digestive tract content: 0.357-1.076 Nm3/kg-VSadded; Intestine

residue: 0.511-0.848 Nm3/kg-VSadded; blood: 0.450-0.799 Nm3/kg-VSadded

stp

Shen et al. 2014

Bamboo waste from a chopstick production factory.

Anaerobic sludge collected from a mesophilic biogas

digester feed with dewatered sewage sludge from a local wastewater

treatment plant .

acid, alkaline, enzyme and alkaline aided

enzymena

triplicates (in some

cases duplicates)

2 37Intermittent, set at 1.5 Hz with 60 s on

and 60 s off30-33 na 25-303.3 ml CH4/g VS

Cano et al. 2014

biological sludge thickened - WWTP; OFMSW - synthetic mixture of foods; MSW sorted from a waste treatment plant;

grease waste a DAF - WWTP; spent grain from brewery

industry; cow manure from slaughterhouse.

WWTP mesophilic digested sludge

Thermal hydrolysis (120-170 ⁰C)

300 triplicate 1:1 VS 35 stirred in a horizontal shaker

app. 40Periodical monitoring analyses of

biogas production by pressure meter. GC

184-524 mLCH4/gVSin

Ferreira et al. 2014

Pig slurry

anaerobic inoculum used was taken from a pilot

sludge digester treating activated sludge

Thermal steam explosion (120-180 ⁰C)

300 190 triplicate 2 gVS/VS 35.1 constant mixing in a shaker table

app. 40 manually by a pressure transmitter. GC-TCD

159-329 mL CH4/gVSfedSTP – 0 ºC,

1 atm

Yong et al. 2015

Food waste and straw shredded to a small size

Anaerobic granular sludge -UASB reactor treating

starch processing waste water at 35 ⁰C

- 1000 400 triplicate 0.014 g VS /12 g VS

35 50 rpm 8 water dislocation method and GC-TCD 0.157-0.392 m3CH4/kg VSstp (0 ⁰C,1.013 x 105

Pa)

Suhr et al. 2015

Solid waste produced in recirculating aquaculture systems Digested cow manure - 540 340 triplicate 4, 8 and 16 g/g 35 24 GC 359 ± 29 mL CH4g−1TVS

stp (20 ºC, 1 atm.)

Nuchdang et al. 2015

variety of paragrass samples

Mesophilic anaerobic sludge was obtained from a

domestic wastewater treatment plant in Bangkok, Thailand. A portion of the sludge was acclimated to fibrous substrates in raw

palm oil mill effluent

- 100 40 1 g VS/g VS 32-35 80 periodically with syringes and GC 277 and 316 ml STP/g VSSTP: 0 ºC and 1 atm

Xue et al. 2015

Dewatered/high solid sludge from a municipal WWTP

pre-incubation at 35 ⁰C in a water bath for 2 d

Low-temperature thermal (60-90 ⁰C) and

high-temperature thermal (120-180 ⁰C) hydrolysis process

500 2/1 VS 37 120 rpm 28 GC/TCD0.94 -1.07 L biogas/g VS

removed

Abelleira-Pereira et al. 2015

Secondary sewage sludge - WWTP

Anaerobically digested sludge - mesophilic

anaerobic digester fed with mixed sludge from the local

WWTP

thermal hydrolysis and advanced thermal

hydrolysis (with hydrogen peroxide)

(90-170 ⁰C)

160 60 triplicate 2 35Constant mixing

by an orbital mechanical shake

28periodically with a manual pressure

transmiter and GC-TCD 227-327 mLCH4/gVSfed

stp (P=1 bar and T=0 ºC)

Carlsson et al. 2015

Composite slurry samples

Digestate collected from a codigestion plant treating SSOFMSW, manure and

industrial waste.

1000 700 5 replicates

2/1 VS 37 35 With gas tight syringe and GC-TCD 445-568 m3 N CH4/ton VS introduced

STP: 0 ºC and 1 atm

Kinnunen et al. 2015

wastewater treatment plant that treats pulp and paper industry

wastewater.

Mesophilically digested municipal sewage sludge Wastewater Treatment

Plant and digestate from CSTR

thermal (80-134 ⁰C) 120 60 2 VS/VS 35 35 water displacement and GC-FIDbetween 40 and 160 N L

CH4 kg-1 VS

normal temperatur

e and pressure

(NTP)Witarsa

& Lansing,

2015

Both unseparated manure and separated manure

BARC mesophilic digester treating the separated dairy

manure.250 120 triplicate

1 VS unseparated manure; 2 VS

separated manure

14 and 24 (in separated chambers)

no mixing 216at least once every week using a

graduated, gas-tight, wet-tipped 50mL glass syringe. GC-FID

107-479 mLCH4/g VS added stp (0 ◦C and 1 atm)

Yin et al. 2015

Pharmaceutical sludge obtained from a pharmaceutical factory

Inoculum sludge - digester from fecal sludge c

1000 0, 0.65, 2.58 and 10.32 TS

37 app. 55 water dislocation method and Biogas Analyzer (daily)

6.98-499.46 mL biogas / g TS pharmaceutical sludge

Rico et al. 2015

solid fraction (SF) of dairy manure. Raw manure slurry was separated

into solid and liquid fractions

screened liquid fraction (LF) of dairy manure

digested at 50 ⁰C500 1 VS

35 for manure and

LF. 50 for SF.

manually stirred once a day

80 pressure measurement and GC-TCD298 (manure), 343 (LF) and

265 (SF) L CH4 kg-1 VS

Ruggeri et al. 2015

Olive mill wastewaters (OMWW) and olive pomace (OP) Bovine manure

NaOH, Salts, Ultrasonic,

Ultrasonic+salts250 triplicate 30 70 rpm app. 60 water dislocation method and GC 2-193 L CH4 /kgVS0

Ebner et al. 2016

Commercial food waste. Dairy manure slurry

post solid separated effluent - complete mix anaerobic digester at

mesophilic codigested dairy manure with assorted

food wastes.

- 500 triplicate 2 gVS/gVS 37 Mixing at 10 s per minute.

33 continuously using the AMPTS II (Bioprocess Control) and GC-TCD

165-496 mL CH4/g VSaddedstp (0 ◦C

and 1 atm)

Khan et al. 2016

Hay (control and standard substrate), peel, stalk, flesh and

unpeeled banana

prepared as described previously (Bolduan et al.,

2011; Brulé, 2014).- 2000

four replicates 0.7 VS 37

1 min every 15 min by magnetic

stirrers35

according to a volumetric method and with a methane analyzer equipped

with an infrared sensor0.256-0.367 m3 CH4/kg VS

stp (0 °C, 1013.25

hPa)Naroznova et al.

2016

source-separated organic household waste

collected from a wastewater treatment plant - 1000

adjusted to 70% 2 VS 37 45 GC-FID 202-572 mL CH4/g VSsubtrate stp

Abudi et al. 2016

thickened waste activated sludge (TWAS) from wastewater

treatment plant. Rice straw (RS) wastewater treatment plant

Thermal and thermo-NaOH for TWAS (70-

90 ⁰C). NaOH and H2O2 for RS.

250 70 duplicate 0.5 TS 37 100 rpm 50 water displacement method and GC-TCD

184.63-401.89 mL biogas/gVSadded

Lu et al. 2016

Food waste from a canteenAnaerobic sludge - up-flow

anaerobic digester of a paper mill

Storage was used as a pretreatment. Food

wastes were separately stored for

0 to 12 days.

1000 triplicate 2:1 VS 35 hand-shaked before sampling

21/60

The biogas produced first flowed into a bottle with 3 mol/L NaOH to absorb CO2, and the remaining gas volume was measured by the principle of

water-displacement and buoyancy

311-571 mL CH4/g-VSadded; 285-696 mL CH4/g-VSadded

Rincón et al. 2016

two-phase olive mill solid waste (OMSW) or alperujo

full-scale anaerobic reactor treating brewery

wastewater at mesophilic temperature

steam-explosion (200 ⁰C). Afterwards a

liquid fraction (LF) and a solid fraction (SF) were obtained.

250 (effective volume)

triplicate 2 VS 35 500 rpm 23

liquid displacement passing the biogas through a 3N NaOH solution

to capture CO2 on the assumption that the remaining gas was methane.

(LF) 589±42 mL CH4/g VSadded; (SF) 263±1 mL

CH4/g VSadded; (Untreated) 366±4 mL CH4/g VSadded

-

Rincón et al. 2013

The two-phase OMSW used was collected from the Experimental

Olive Oil Factory

industrial anaerobic reactor treating brewery wastewater 35 ⁰C

Thermal (100-180 ⁰C)250

(effective volume)

duplicate 2 VS 35 500 rpm period of c.a. 20

liquid displacement passing the biogas through a 3N NaOH solution

to capture CO2 on the assumption that the remaining gas was methane.

373-392 mL CH4/g VSadded

Hernández-Shek

et al. 2016

Water hyacinth (WH) was harvested. Fruit and vegetable

waste (FVW) was collected from typical market

mesophilic anaerobic sewage sludge - upflow sludge blanket reactor

treating domestic wastewater.

- 500 100 triplicate 37 60liquid displacement technique and GC-

TCD

0.114 m3 biogas kg-1

VSadded (WH); 0.141 m3

biogas kg-1 VSadded

(WH+FVW)

Haak et al. 2016

float from a dissolved air flotation unit (DAF sludge) and waste

activated sludge (WAS) collected from a large refinery

active mesophilic AD at a municipal wastewater

treatment plant.

Ozonation in a bubble column setup 60

DAF sludge 2-10 gVS/gVSDAF; Treated DAF sludge 20–100 gVS/gVSDAF;

WAS 5 gVS/gVSWAS

mesophilic conditions constant 30-50

80-160 Lbiogas/kgCODadded

Ware & Power 2016

selected solid waste fractions from cattle, pig and chicken

slaughtering facilities.

granular mesophilic inoculum sourced from a

mesophilic Up-flow Anaerobic Sludge Blanket

(UASB) reactor treating dairy processing waste

Pasteurisation 1000 100 triplicate 2 VS 36-39 daily 30-50

directly through positive liquid displacement. To directly measure the

methane fraction of the biogas produced the biogas was passed

through an alkaline solution

465.34-515.47 mLCH4 gVS-1

(UP); 501.13-650.92 mLCH4

gVS-1 (P)

Pre-treatments - thermal and chemical

Inoculum source - sludge from WWTP

Reactor volume - 60 to 3,000 mLI/S - 2

Incubation time - 7 to 216 d

Biogas - pressure transducer, volume displacement and syringe

Methane content -GC

Results of BMP tests - very discrepant and difficult to compare


Conclusions

• BMP continues to be widely used to analyse the potential organicsolid wastes

• Several attempts were made in recent years to normalise the BMPtests

• The variability of the substrate sources and its characteristics andthe available resources imply adaptation of several operationalconditions tests.

• BMP results, namely the biogas or methane production should bepresented in comparable units.


Future Work

• Application of cheaper BMP methodologies and with less wasteproduction;

• Continue the investigation concerning the availability of potentialsubstrates for anaerobic digestion;

• Promote the waste management – more waste valorisation andless waste to landfill;

• More biogas production - energy resource applications.


Thank you for your attention

Questions ?

email: [email protected]

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