This article was downloaded by: [Lahore University of Management Sciences]On: 18 October 2014, At: 00:30Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: MortimerHouse, 37-41 Mortimer Street, London W1T 3JH, UK

Journal of Environmental Science and Health, PartA: Toxic/Hazardous Substances and EnvironmentalEngineeringPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/lesa20

Anaerobic Digestion and Methane GenerationPotential of Rose Residue in Batch Reactorsİsmail Tosun a , M. Talha Gönüllü b & Ahmet Günay b

a Department of Environmental Engineering , Suleyman Demirel University , Isparta,Turkeyb Department of Environmental Engineering , Yildiz Technical University , Besiktas,Istanbul, TurkeyPublished online: 06 Feb 2007.

To cite this article: İsmail Tosun , M. Talha Gönüllü & Ahmet Günay (2004) Anaerobic Digestion and Methane GenerationPotential of Rose Residue in Batch Reactors, Journal of Environmental Science and Health, Part A: Toxic/HazardousSubstances and Environmental Engineering, 39:4, 915-925, DOI: 10.1081/ESE-120028402

To link to this article: http://dx.doi.org/10.1081/ESE-120028402

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose ofthe Content. Any opinions and views expressed in this publication are the opinions and views of the authors,and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be reliedupon and should be independently verified with primary sources of information. Taylor and Francis shallnot be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and otherliabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to orarising out of the use of the Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH

Part A—Toxic/Hazardous Substances & Environmental Engineering

Vol. A39, No. 4, pp. 915–925, 2004

Anaerobic Digestion and Methane Generation Potential

of Rose Residue in Batch Reactors

_IIsmail Tosun,1,* M. Talha Gonullu,2 and Ahmet Gunay2

1Department of Environmental Engineering,

Suleyman Demirel University, Isparta, Turkey2Department of Environmental Engineering,

Yildiz Technical University, Besiktas, Istanbul, Turkey

ABSTRACT

In the study, anaerobic digestion of residues from rose oil industry was

investigated by using a laboratory scale completely mixed batch reactor in

volume of 10L and 4 small reactors in volume of 400mL. Ten liters reactor

isolated with a water jacket and 0.4L reactors settled into a water bath were

operated at 35� 1�C. The study supplies biochemical methane potential of

hydrolyzed and original residues. Experimental results showed that hydrolyzed

rose residue produced a bit more methane than original residue. Methane

production results were analyzed with first-order and Chen&Hashimoto’s

models, and Chen&-Hashimoto’s model was found to be more suitable than

first-order kinetic model.

Key Words: Anaerobic digestion; Hydrolysis; Isparta; Rose residue; Kinetics.

*Correspondence: _IIsmail Tosun, Department of Environmental Engineering (MMF, Cerre

Muh.), Suleyman Demirel University, 32260, Isparta, Turkey; Fax: +90-246-2370859;

E-mail: ismailt@mmf.sdu.edu.tr.

915

DOI: 10.1081/ESE-120028402 1093-4529 (Print); 1532-4117 (Online)

Copyright & 2004 by Marcel Dekker, Inc. www.dekker.com

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

INTRODUCTION

Rose (Rosa Damascena Mill.) is a species being used to produce attar of rose by

distilling volatile oils from flowers. It is also consumed for the production of rose

concrete, absolute and water as fragrance and flower agents for the perfume,

cosmetic, pharmaceutical and food industries.Turkey has an important role among the countries that are world rose oil

producers. The rose oil is heavily produced in Isparta province of Turkey. The yearly

amounts of rose flower harvested for rose oil production in Turkey have been varied

as shown in Fig. 1. One unit of rose flower milled gives about two units of residue in

wet weight basis. The content of solids in wet residue is around 10% that is consisted

of 90% organics. Due to the putrescible aspects of the residues, a substantial

environmental problem is caused for a short season period between May and June

months; especially for aquatic bodies that some of them are used for supply potable

water.Today’s World is in an intensive investigation of alternative sources of energy as

well as environmental considerations. Biogas production through anaerobic

fermentation from agricultural and animal wastes has been looked upon as a

promising energy source, especially for developing countries. By this way, the crop

residues have had been converted to a clean, readily useable and high-energy

contented fuel (methane). The advantages of anaerobic process are high degree of

waste stabilization, low production of waste biological sludge, low nutrient

requirements, reduction in pathogens, no oxygen requirements, and production of

biogas as a useful end product. Biogasification also stabilizes the wastes while

providing environmental and cost-effective benefits. Mata-Alvarez et al.[1] reported

that biogas production could reach over 15-millionm3 d�1 of methane throughout

Europe.Only the biodegradable fraction of organics has a potential for bioconversion.

Anaerobic bacteria do not easily degrade the refractory organics such as lignin, and

complete degradation requires a long period. Table 1 gives anaerobic digestion

experience data produced for some waste types.[2–4]

0

5000

10000

15000

20000

25000

30000

1985 1990 1995 2000

Years

Ros

e fl

ower

pro

duct

ion

(t)

Figure 1. The amounts of rose flower harvested in Turkey cities. i Isparta; þ Turkey.

916 Tosun, Gonullu, and Gunay

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

The main objective of this study is to find out biochemical methane potential ofresidues from rose oil industry by using five laboratory scale completely mixed batchreactors. The study also supplies kinetic analysis of experimental findings obtainedfrom hydrolyzed and original residues.

MATERIAL AND METHODS

Reactors

Totally five reactors were used for the study; one reactor (Reactor A) in 10L andthe others (R1 to R4) in 0.4 L in operating volumes. Reactor A was isolated withwater jacket to keep reactor temperature at 35� 1�C. In order to get the completelymixing conditions, Reactor A was equipped by a speed adjustable verticalmechanical mixer (Fig. 2). Reactors R1 to R4 were placed in a thermostat controlledwater bath to keep reactor contents at 35�C, and agitated by magnetic stirrer.Physical and operational properties of all reactors are outlined in Table 2.

The Reactor A was operated for 3 sequential feedings: 90 g, 90 g and 270 g VSfeedings were made on 1st, 11th and 36th days, and terminated on 75th day.

Materials

Chemical specifications of the samples supplied from a rose oil factory(Gulbirlik) located in Isparta City in Turkey are given in Table 3. Original residuesample was fed into Reactor A as slurry without any pretreatment. On the otherhand, slurry preparations obtained from dried and grinded residues (0.3mm) wereused for Reactors R1 to R4. Seed sludge supplied from Pas� abahce Alcohol Factoryin Istanbul, was mixed in 15% volumetrically with the slurry. Just after feedingsubstrate and seed material, gases in the dead volume above the mixed liquor wasswept away by nitrogen gas. Two of four small reactors (R1 and R2) were used tofind out the effect of hydrolysis of wastes on anaerobic decomposition. Hydrolysiswas carried out in 0.1N NaOH, in an autoclave (1 atm, 121�C, 2 h in). After

Table 1. Anaerobic digestion experience data dealing with some waste types.

Organic substance

Methane prod.

(m3 (kg-VS)�1)

Methane content

( %) Reference

Agricultural residues 0.337 58.6 Badawi et al.[2]

Village waste — 62.5 Badawi et al.[2]

MSW 0.24 59.6 Badawi et al.[2]

MSW 0.2 — Chynoweth et al.[3]

85%-MSWþ15% sludge 0.29–0.23 57–53 Szikriszt[4]

Anaerobic Digestion and Methane Generation Potential of Rose Residue 917

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

Figure 2. Digestion process apparatus. 1. Reactor, 2. Feeding, 3. Outlet, 4. Thermostated

water bath, 5. pH and temperature probes, 6. Mixer, 7. H2S trap, 8. Gas collection vessel.

(View this art in color at www.dekker.com.)

Table 3. Chemical specifications of rose oil residue (dry basis).

Constituent Unit Value Metal Unit Value

Water content % 90.5 Mn mgkg�1 171

Volatile solids % 91.3 Cu mgkg�1 12.2

TOC % 50.6 Zn mgkg�1 85

TOC/OM — 0.60 Ni mg kg�1 4.0

TKN % 3.7 Na % 0.1

C/N — 13.6 K % 2.4

pH — 5.1 Ca % 1.6

Tot. P (PO4–P) mg kg�1 990 Mg % 0.5

Fe % 0.2

Table 2. Properties of the reactors used in the experiments.

Small reactors

Reactor A R1 R2 R3 R4

Operating vol. (L) 10 0.4 0.4 0.4 0.4

Mixer Paddle Stirrer Stirrer Stirrer Stirrer

Temperature (�C) 35� 1 35� 1 35� 1 35� 1 35� 1

Feed manner Sequential

batch

Only once

pouring

Only once

pouring

Only once

pouring

Only once

pouringFeed rate (gVSL�1) 9–9–27 11.25 22.5 11.25 22.5

Pre-treatment — Hydrolysis Hydrolysis — —

918 Tosun, Gonullu, and Gunay

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

neutralizing the pH, material was poured into the reactors. The other two of thereactors (R3 and R4) were filled up with no hydrolyzed material.

Test Chemicals and Analysis

Analytical grade chemicals in accordance with Standard Methods realized allchemical analysis for Water and Wastewater[5] and Methods of Soil Analysis.[6]

Heavy metals were determined by atomic absorption spectrometer (UNICAM 929).Alkali and earth alkali metals were determined by flame photometer (Jenway PFP7).Daily fermentation gas production was measured by liquid displacement method. AnOrsat-type gas analyzer measured the composition of decomposition gas.

EXPERIMENTAL RESULTS

Reactor A Results

Before and after each feeding the Reactor A, supernatants of reactor contentswere analyzed and the results obtained were given in Table 4. These data point thatrequired nutrients for an adequate fermentation are exist in the residue of roseflowers, it is more than advised ratio (COD:N:P¼ 400:7:1) by Henze andHarremoes.[7] Ammonia nitrogen being a product of degradation was found aquite low level. Other essential parameters such as pH and alkalinity were adequatefor anaerobic decomposition.

As can be seen from Fig. 3, methane formation starts and accelerates almostimmediately after feeding, and reaches a maximum rate in a few days. This explainsthat the residue has capabilities of convenient decomposition and readilyacclimation. Decomposition rates decrease drastically through first 5 days andkeep on almost a stable rate after 10th day.

After each feeding step, total methane formation was determined as 0.19, 0.37,and 0.22L methane (g VSadded)

�1, respectively. Average total methane formationwas found to be 0.25L methane (g VSadded)

�1. This value obtained for the residueshows a close similarity with other types of wastes given in Table 1.

Average methane content in the decomposition gas was 72%. Figure 4 showschange of methane percent vs. overall operation time. The methane percent obtainedfor the rose residue is found relatively higher than that for organic municipal solidwaste (MSW) having typically 55–70% as reported by Braber.[8] It is noted that eachton residue in dry basis gives higher amount of biogas (310m3) than organic MSWbiogas production (100–200m3).

Reactor R1 to R4 Results

The results of decomposition experiments conducted in Reactor R1 to R4 tocompare the hydrolysis effect on the substrate were illustrated in Figs. 5 and 6. The

Anaerobic Digestion and Methane Generation Potential of Rose Residue 919

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

gas measurements for about 40 days showed that hydrolyzed material produced 8%

more biogas than original material. Cumulative methane productions for original

and hydrolyzed materials were 0.26 and 0.28L methane (g VS)�1, respectively. These

results showed that reactors with original materials (Reactor A, R3 and R4) almost

0,00

0,05

0,10

0,15

0,20

0,25

0 5 10 15 20 25 30 35 40 45

Time (day)

Cum

ulat

ive

met

hane

(l (

g-V

S)-1

)

0,000

0,005

0,010

0,015

0,020

0,025

0,030

Dai

ly m

etha

ne (

l (g

VS

day)

-1)

Figure 3. Daily and cumulative methane production in step 3 for Reactor A. s Cumulative

methane; ^ Daily methane.

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80

Met

hane

(%

)

Time (day)

FeedingFeeding

Figure 4. Methane percent in decomposition gas of Reactor A.

Table 4. Initial and final parameters for each step in Reactor A.

Feeding step pH

Alkalinity

(mgL�1)

COD

(mgL�1)

TKN

(mgL�1)

NH3-N

(mgL�1)

P

(mgL�1)

1st Initial 7.4 1650 2950 390 275 41

Final 7.1 1860 1010 358 265 34

2nd Initial 7.2 2100 3200 487 320 43

Final 7.1 2200 1800 473 310 35

3rd Initial 7.3 2200 6500 — 415 —

Final 7.2 2250 4350 — 410 —

920 Tosun, Gonullu, and Gunay

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

produced same amount of methane values. However, contents in R1 and R2Reactors with hydrolyzed material produced a bit more methane in comparison withother reactors with original materials. As it can be seen from Fig. 6, methaneproduction increased with decreasing organic loading rate.

Kinetic Analysis

Anaerobic digestion is a bacterial fermentation process and essentially its kineticreflects growth of bacterial species. In this study the experimental results wereanalyzed for kinetic models given below.

0

0,02

0,04

0,06

0,08

0 10 20 30Time (day)

l CH

4 ( g

VS-

d)-1

(a)

00,010,020,030,040,05

0 10 20 30Time (day)

l CH

4 (g

VS

-d)-1

(b)

Figure 5. Daily methane production: a) hydrolyzed, b) original residues. s R1; i R2.

0,0

0,1

0,2

0,3

0,4

R1 R2 R3 R4 Reactor A

CH

4

(l (

g V

S in

itia

l)-1

)

Figure 6. Methane production of hydrolyzed and original material. X Hydrolyzed; œOriginal.

Anaerobic Digestion and Methane Generation Potential of Rose Residue 921

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

First-Order Kinetic Model

Anaerobic digestion is generally described by first-order reaction kinetic:

Y ¼ Ymax 1� e�k1t� �

ð1Þ

in which;

Y is the methane yield (L CH4 (gVS)�1),

k1 is first-order reaction rate coefficient (day�1),Ymax is maximum methane yield (L CH4 (gVS)

�1).

Chen and Hashimoto’s Model

Chen and Hashimoto’s model is expressed as follows:

Si

S0¼

k

HRT�max þ k� 1ð2Þ

where,

Si: outlet substrate concentration (mgL�1),S0: inlet substrate concentration (mgL�1),HRT: hydraulic retention time (days),k: Chen and Hashimoto kinetic constant,�max: maximum specific growth rate of microorganisms (day�1).

Substrate concentration is measured by means of COD in common. CODremoval is an indicator of biogas production in anaerobic processes:

Si

S0¼

Ymax � Y

Ymaxð3Þ

for this reason, Eq. (2) could be expressed, in terms of biogas yields, as follows:

Y ¼ Ymax 1�k

HRT�max þ k� 1

� �ð4Þ

which can be converted to:

Ymax

Ymax � Y¼

HRT�max

kþ 1�

1

kð5Þ

Ymax/(Ymax�Y ) against hydraulic retention time will lead to a straight line with theslope �max/k and the intercept 1� 1/k.

The critical retention time for when washout takes place the following value:

tc ¼1

�maxð6Þ

Thus, the shorter this time is, the better the reactor will operate.

922 Tosun, Gonullu, and Gunay

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

In order to compare the fitness degree of kinetic equations, the root mean square

(RMS) of the normalized residuals was calculated by

RMS ¼

ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiPðYexp � Y calcÞ

2

N

sð7Þ

where; N is number of data points.In Fig. 7, biogas production capability data simulated by means of each model

was compared to experimental data. Kinetic parameters obtained by using first-

order model and Chen&Hashimoto’s model for hydrolyzed and original materials

are listed in Table 5.The comparisons of models with the data are presented in Fig. 7 and Table 5.

The experimental results showed that Chen&Hashimoto’s model is found to be more

suitable than first-order kinetic for expressing the microbial kinetics of anaerobic

decomposition of rose residue by taking into consideration the RMS of the

normalized residuals.

0,0

0,1

0,2

0,3

0 10 20 30 40

Time (day)

l CH

4 (

gVS

)-1

R1

R2

(a)

0,0

0,1

0,2

0,3

0 10 20 30 40

Time (day)

l CH

4 (

gVS

)-1

R3

R4

(b)

Figure 7. Comparison of the theoretical and experimental CH4 production for biochemical

methane potential experiments: a) hydrolyzed; b) original residues. s R1-Exp.; f R2-Exp.;

- - - First order; — Chen&Hashimoto.

Anaerobic Digestion and Methane Generation Potential of Rose Residue 923

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

CONCLUSIONS

The following conclusions can be drawn from the experimental results: Rose

residue can be treated under anaerobic conditions, found to be a quite feasible

method for a possible stabilization process, leading to production of biogas in

significant amounts. This was succeeded with a seed sludge supplied from an alcohol

factory in a short acclimation period of only a few days.The pretreatment of the residue was supplied a few more increment on methane

production in comparison with original residue. Anaerobic methane generation from

hydrolyzed and original rose residue was found to be 0.28 and 0.26L CH4 (g VS)�1,

respectively. High methane content (average 72%) was observed by anaerobic

bioconversion of rose residue. Original and hydrolyzed residues have become stable

in 20 and 10 days at 35�C, respectively. Chen & Hashimoto’s model was more

adequate than first-order kinetic to describe experimental data on methane

production by anaerobic decomposition of rose residue.

ACKNOWLEDGMENTS

The work was supported by Research Fund of Yildiz Technical University

(Project No: 22-05-02-01).

REFERENCES

1. Mata-Alvarez, J.; Mace, S.P.; Llabres, P. Anaerobic digestion of organic solid

wastes: an overview of research achievements and perspectives. Bioresource

Technology 2000, 74, 3–16.

Table 5. Values of kinetic parameters.

Loading rate

(gVSL�1)

Hydrolyzed Original

11.25 22.5 11.25 22.5

First order

k1 0.287 0.274 0.176 0.185

Ymax 0.289 0.225 0.279 0.214

RMS 0.018 0.016 0.015 0.012

Chen&Hashimoto

�max 1.819 1.973 1.044 1.048

K 5.200 5.688 5.350 5.271

tc 0.550 0.507 0.958 0.954

Ymax 0.325 0.250 0.336 0.260

RMS 0.016 0.014 0.008 0.007

924 Tosun, Gonullu, and Gunay

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

ORDER REPRINTS

2. Badawi, M.A.; Blanch, F.C.; Wise, D.L.; El-Shinnawi, M.M.; Abo-Elnaga, S.A.;

El-Shimi, S.A. Anaerobic Composting with Methane Recovery from

Agricultural and Village Wastes. Proceedings of the Industrial Waste

Conference, 1991, 727.3. Chynoweth, D.P.; Owens, J.M. Biochemical methane potential of municipal

solid waste components. Water Science Technology 1993, 27, 1–14.4. Szikriszt, G. Full Scale Demonstration Plant for Anaerobic Digestion of Sorted

Municipal Solid Waste; Swedish Environmental Research Institute: Stockholm,

Sweden, 1992.5. American Public Health Association. Standard Methods for the Examination of

Waste and Wastewater, 19th Ed; Water Environment Federation: Alexandria,

VA, 1995.6. Methods of Soil Analysis: Chemical Methods, Part 3; Soil Science Society of

America, Inc.: Wisconsin, USA, 1996.7. Henze, M.; Harremoes, P. Anaerobic treatment of wastewater in fixed film

reactors—a literature review. Wat. Sci. Tech. 1983, 15 (8–9), 101.8. Braber, K. Anaerobic digestion of municipal solid waste: a modern waste

disposal option on the verge of breakthrough. Biomass and Bioenergy 1995,

9 (1/5), 365–376.

Anaerobic Digestion and Methane Generation Potential of Rose Residue 925

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014

Request Permission/Order Reprints

Reprints of this article can also be ordered at

http://www.dekker.com/servlet/product/DOI/101081ESE120028402

Request Permission or Order Reprints Instantly!

Interested in copying and sharing this article? In most cases, U.S. Copyright Law requires that you get permission from the article’s rightsholder before using copyrighted content.

All information and materials found in this article, including but not limited to text, trademarks, patents, logos, graphics and images (the "Materials"), are the copyrighted works and other forms of intellectual property of Marcel Dekker, Inc., or its licensors. All rights not expressly granted are reserved.

Get permission to lawfully reproduce and distribute the Materials or order reprints quickly and painlessly. Simply click on the "Request Permission/ Order Reprints" link below and follow the instructions. Visit the U.S. Copyright Office for information on Fair Use limitations of U.S. copyright law. Please refer to The Association of American Publishers’ (AAP) website for guidelines on Fair Use in the Classroom.

The Materials are for your personal use only and cannot be reformatted, reposted, resold or distributed by electronic means or otherwise without permission from Marcel Dekker, Inc. Marcel Dekker, Inc. grants you the limited right to display the Materials only on your personal computer or personal wireless device, and to copy and download single copies of such Materials provided that any copyright, trademark or other notice appearing on such Materials is also retained by, displayed, copied or downloaded as part of the Materials and is not removed or obscured, and provided you do not edit, modify, alter or enhance the Materials. Please refer to our Website User Agreement for more details.

Dow

nloa

ded

by [

Lah

ore

Uni

vers

ity o

f M

anag

emen

t Sci

ence

s] a

t 00:

30 1

8 O

ctob

er 2

014