Anaerobic digestion of whey

1. 1
CYPRUS INTERNATIONAL UNIVERSITY
INSTITUITE OF GRADUATE STUDIES AND RESEARCH
Environmental Science Department
Anaerobic Digestion from Whey waste
Seminar Presentation
Presented by:
Sulaiman Ishaq MUKTAR – 20142930
supervisor
Asst. Prof. Dr.Emrah A. ERKURT

2. outline
• Introduction
• Aims and objectives
• Justification
• Materials and methods
• Reference

3. Introduction
• Anaerobic digestion is a series of biological processes in which microorganisms break
down biodegradable material in the absence of oxygen.(American biogas council).
• A range of anaerobic digestion technologies are converting livestock manure, municipal
solids waste, food waste, high strength industrial wastewater and residuals, fats, oils and
grease (FOG), and various other organic waste streams into biogas.
• An important product of AD is methane; a biogas which can be use directly as cooking
gas or combusted to generate electricity, heat, or can be processed into renewable
transportation fuels (Seghenzzo 2004.,Svard.,2003)
• Sludge from AD can be utilized for dairy bedding, composted or directly applied to
cropland as nutrient source for plants

4. • Whey, also called milk serum or milk permeate, is the liquid
remaining after milk has been curdled and strained. It is a by-product
of the manufacture of cheese or casein.

5. Typical Characteristics of diluted whey
• Parameter Whey
• pH (at 22◦C) 3.5
• Total solids (% w/w) 7.8
• Volatile solids (% w/w) 4.8
• COD (gO2/L) 74.9
• Ash (% w/w) 2.8
• Ammonia nitrogen (g/L NH3-N) 0.06
• Total nitrogen (g/L N) 1.02
• Alkalinity (g/L) 0
• Proteins (% w/w) 0.6
• Oil and grease (% w/w) 0.7
• Phenols C6H5OH (mg/L) 0.5
• Phosphorous (g/L) 0.3
• COD:N ratio 73.4
• C:N ratio 24.1
Gelegenis et al., 2007

6. Process step of anaerobic digestion
• Hydrolysis
 it consist of breaking of polymer into smaller molecules.
 is a slow step in AD.
• Acidogenesis
 carried out by diverse group of fermentative bacteria.
 participate in the degradation of sugars and aminoacids
• Acetogenesis
 Acetogenic bacteria are responsible for oxidation of the products generated for methanogenic
organisims
 Products generated by acetogenic bacteria are acetic acid,hydrogen and CO2.
• Methanogenesis
 Final phase (CH4)
 Methanogenic organisims
 Acetate using microorganisms (acetilastic methanogens),responsible for 60-70% CH4 production
 Hydrogen-using microorganisims(hydrogenotrophic methanogens).

7. Process step of anaerobic digestion

8. Aims
• The aim of this research is to determine;
• Waste reduction and treatability of Whey in AD
• methane yield of whey
• analysis of sludge after digestion for further use
• objectives
• Collection and Analysis of whey from Mera dairy company
• Pre-treatment of whey to reduce start-up problem
• Operating system; i.e. batch or continuous
• Methods of H2S mitigation
• How to measure the yield

9. Justification
• Agro-industries such as olive oil mills, cheese factories and dairy farms contribute to the
local economy of Mediterranean countries.
• Agro-industries are major contributors to the worldwide industrial pollution problem.
Therefore, agro-industries more than any other industrial sector require a dynamic and
comprehensive waste management systems.
• Industries processing agricultural raw materials such as various fruits, vegetables, meat,
milk e.t.c. generate millions of tons of wastes and large amounts of by-products, which
are totally unexploited and the absence of environmental management is significantly
dangerous for the environment.

10. Justification conti.
• Furthermore cheese factories generate wastewaters of which cheese whey (CW) is the most
important waste stream produced with a high organic content (up to 70 g COD/L), which is
highly biodegradable, and low alkalinity (50 meq/L)
• Amount of cheese whey in the word is over 108 tonnes per year (Ozmihci and Kaygi, 2008).
• Cheese whey with high carbohydrate, protein and lipid contents is an important source of
environmental pollution (Grba et al., 2002), hence, waste of cheese whey represents a
significant loss of resources and causes serious pollution problems
• Why ?

11. • whey is a heavy organic pollutant with a high biochemical oxygen demand (BOD) of 40 000 to 60 000
ppm and a chemical oxygen demand (COD) of 50 000 to 80 000 ppm (Ben-Hassan and Ghaly, 1994).
• Disposing of whey provides no valuable product, and is costly and labour demanding for the cheese
manufactures, who generally bears all the direct costs of handling and transport. Whey problem must be
considered as a resource and not only as a waste effluent, in view of its large potential as a source of added
value products (Pedro et al., 2010).
• In 2008, Minerva Cheese Factory agreed to pay more than $6,000 in restitution after it accidentally
released acid whey into Sandy Creek, Ohio, which temporarily depleted oxygen levels and killed more
than 5,400 fish along a 1.5 mile stretch downstream.

12. MATERIALS
• A pilot process design will be done in the laboratory to produce
biogas. These will include
• 250ml volumetric flask
• Measuring cylinder
• Tubes
• Whey collected from Mera diary company
• NaOH, Ca(OH)2
• TOC analyser
• Cornical flask, pipette, burrette
• Inoculum
• pH meter

14. METHODS
• Collection of whey
• Chemical degradation of whey(if required)
• Filtration(if required)
• Characterisation of whey
• pH determination whey: 6.5–8.0(in anaerobic digestion).
• Set up of anaerobic digester system: A pilot process design will be done in the
laboratory to produce biogas.At a temperature of 37◦C
• Determination of specific methanogenic activity(SMA) test.
• Specific methanogenic activity (SMA) is done in order to determine the maximum
activity of the digestion, the maximum amount of methane gas that can be
produced per day per gram of bacteria present.
• Determination of Methane

15. METHODS CONTD.
Biodegradability: The anaerobic biodegradability can be defined as
the percentage of chemical oxygen demand present in a sample that is
converted into methane under anaerobic conditions.
Hydrolysis:The hydrolysis will be done to get information about the
rate of degradation of the suspended particles within the whey waste. It
will be done while hydrolysis of suspended particles is considered to be
the rate-limiting step in anaerobic digestion.

16. THANK YOU

17. References
• Ben-Hassan, R.M. and Ghaly, A.E. 1994. Continuous propagation of Kluyveromyces fragilis I cheese whey for pollution potential production. Appl.
Bioche. Bioteychnology 47: 89-105.
• Grba, S., Tomas, V.S., Stanzer, D., Vahcic, N. and Skrlin, A. 2002. Selection of yeast strain Kluyveromyces marxianus for alcohol and biomass
production on whey. Chem.Biochem.Eng.Q. 16: 13-16
• Gustaf Alm, Göran Eriksson, Hans Ljunggren, Inger Palmstierna and Nils Tiberg (1991) Kompostboken. LTs förlag, Sverige ISBN: 91-36-03092-9
• Kujewa K, Zeeman G. (2005). Anaerobic treatment of concentrated wastewater in DESAR concept. STOWA,the Netherlands
• Lucas Seghezzo and Adriaan Mels (2005). Hydrolysis and biodegradability tests – Laboratory guidelines to perform hydrolysis and anaerobic
biodegradability tests. Lettinga Associates Foundation
• Pedro, M.R., Guimaraes, J., Teixeira, A. and Domingues, L. 2010. Fermentation of lactose to bio-ethanol by yeasts as part of integrated solutions for the
valorisation of cheese whey. Biotechnology Advances 28: 375-384
• Seghezzo Lucas (2004). Anaerobic treatment of domestic wastewater in subtropical regions, Ph.D thesis,Wageningen University, the Netherlands.
ISBN: 90-8504-029-9
• Svärd Å. (2003). Anaerobic digestion of urban organic waste –Evaluation of potentials, licentiate thesis, Lund University, Sweden. ISBN: 1650-5050
• John Gelegenisa,, Dimitris Georgakakisb,Irini Angelidakic, Vassilis Mavrisa 2007. Optimization of biogas production by co-digesting whey with diluted
poultry manure. Renewable Energy 32.pp 2147–2160
• www.amerianbiogascouncil.org
• www.achaia.gr