Characteristics and Sources of Municipal Solid Wastes

1. 17CE413
SOLID AND HAZARDOUS
WASTE MANAGEMENT
Prof. M.R.Ezhilkumar
Assistant Professor
Department of Civil Engineering
Sri Krishna College of Engineering and Technology
Coimbatore
ezhilkumar@skcet.ac.in
I only feel angry when I see waste.
When I see people throwing away things
we could use. – Mother Teresa
1
1.3 – Characteristic of Solid Waste

2. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 2
☼ Composition of MSW
☼ Characteristics of MSW
 Quantification
 Estimation methods
1.3 – Characteristic of Solid Waste
Learning Outcomes

3. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 3
Video Session 1

4. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 4
Video Session 2

5. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 5
Composition of MSW
Composition studies
 Manual sorting of waste components into predefined categories
 Knowledge of individual components important for,
 Recycling impact,
 Calculation of physical properties,
 Combustion characteristics, and
 Landfill requirements
 Need to be performed seasonally to define,
 Equipment needs,
 Management programs, and
 Trends for future planning
The sampling plan drives
the waste composition
study

6. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 6
Composition of MSW
The waste composition varies
from country to country, and
between different regions of one
country. On the whole, there are
significant differences between
European and Asian countries
Source:
Solid Waste Management, Volume I,
United Nations Environment
Programme, 2005.

7. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 7
Composition of MSW
Global Perspective on General Urban Solid Waste composition

8. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 8
Characterisation of MSW
Importance of Quantification and Characterisation of MSW
• Planning day to day collection, transportation and disposal
• Estimating resource requirement
• Developing solid waste management system
• Designing treatment and disposal facility
• Future planning of solid waste management system

9. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 9
Characterisation of MSW
Characterisation
is
not just
sample analysis

10. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 10
Characterisation of MSW (Quantification)
Objectives
o To estimate existing waste quantities from different sources of waste
generation
o To estimate waste generation rate
o To estimate future quantities of waste for the planning period
Methodology
o Actual weighing of waste quantities
o Knowing the population and waste generation rate
o Knowing volume and density of waste

11. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 11
Characterisation of MSW (Estimation methods)
Physical characterisation
Methodology
 Collect around 100 kg of well mixed waste sample
 Obtain about 12.5 kg of sample by conning and quartering method
 Segregate each ingredient from the sample and weigh
 Express each ingredients as percentage
 Mix all compostable material
 Take about 500 gm of well mixed compostable material
 Estimate moisture content by oven drying at 105oC
 Grind oven dried sample for further chemical analysis

12. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 12
Characteristics of MSW (Estimation methods)
a) Specific weight
b) Moisture content
c) Particle Size
distribution
d) Field capacity
e) Permeability
f) Calorific value
a) Proximate
analysis
b) Fusing point of
ash
c) Ultimate analysis
of MSW
d) Energy content of
MSW
e) Toxicity
a) Biodegradability
b) Organic fraction
Physical Chemical Biological

13. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 13
Characterisation of MSW (Estimation methods)
Physical characterization
Moisture Content
Moisture content of solid wastes is usually expressed as the weight of moisture
per unit weight of wet material.
Wet weight – weight of sample including water, kg
Dry weight – weight of sample after drying at 105oC, kg

14. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 14
Characterisation of MSW (Estimation methods)
Physical characterization
Moisture Content
• A typical range of moisture contents is 20 – 45% in waste in arid climate and in
wet seasons having large precipitation.
• Values greater than 45% are however not uncommon.
• Increase in MC, increases the weight, cost of collection and transport of MSW
respectively.
• MC is a critical determinant in economical feasibility of waste treatment &
processing (incineration methods)
• MC – Higher in lower income countries

15. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 15
Characterisation of MSW (Estimation methods)
Physical characterization
Calorific value
 Calorific value is the amount of heat generated
from combustion of a unit weight of a substance,
expressed as kcal/kg.
 Determined experimentally using Bomb
Calorimeter in which the heat generated at a
constant temperature of 25OC from the
combustion of a dry sample is measured.

16. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 16
Characterisation of MSW (Estimation methods)
Physical characterization
Calorific value
»A sample of known weight is placed into the bomb and the two halves are
screwed shut.
»Oxygen under pressure is then injected into the bomb and then the bomb is
placed in an adiabatic water bath with wires leading from the bomb to a source
of electric current.
»Material in the bomb is combusted by a spark from the wires, heats the bomb,
which in turn heats the water.
»Temperature is measured and recorded as a function of time.

17. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 17
Characterisation of MSW (Estimation methods)
Physical characterization
Calorific value
»Heat energy is calculated in calories as the temperature increase of water times
the mass of the water plus bomb.
»Knowing the weight of sample, its heat value can be computed.
»Each calorimeter must be standardized using a material (benzoic acid) for
which the heat of combustion is known precisely to get the heat capacity (Cv) of
the calorimeter.

18. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 18
Characterisation of MSW (Estimation methods)
Physical characterization
Calorific value
»Heat capacity of (CV) of the calorimeter (Cal/oC)
CV = (U. Mb) / (∆T)
U = Heat of combustion of benzoic acid (6318 Cal/g)
Mb = Mass of benzoic acid pellet
∆T = Rise in temperature from thermogram
» Heat value of unknown material,
= (CV.∆T)/M
M = Mass of the unknown material (g)

19. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 19
Characterisitcs of MSW
Source: Worrell et al., Solid Waste Engineering, Second edition, Cengage Learning, 2012.

20. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 20
Characterisitcs of MSW
Source: Worrell et al., Solid Waste Engineering, Second edition, Cengage Learning, 2012.

21. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 21
Characterisitcs of MSW
Source: Worrell et al., Solid Waste Engineering, Second edition, Cengage Learning, 2012.

22. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 22
Assessment Time
Review
Question
Estimate the moisture content, Density and Energy content of a solid
waste sample that has following components. Use suitable data from
the given list of components and its respective mass percentage.
(1) Food waste - 14%; (2) Paper - 40%; (3) Cardboard - 9%;
(4) Plastics - 9%; (5) Yard wastes - 12%; (6) Wood - 5%;
(6) Tin cans - 6%

23. SHWM – Module 1 – Characteristics and Sources of Municipal Solid Wastes  Mr.M.R.Ezhilkumar 23
Characterisitcs of MSW
Source: Worrell et al., Solid Waste Engineering, Second
edition, Cengage Learning, 2012.