What is Waste?
Types
1.Solid Waste
2. Liquid Waste
3. Gaseous Waste
Classification of Waste
• On the basis of Physical State
– Solid Waste
– Liquid Waste
– Gaseous Waste
• According to Original Use
– Food Waste
– Packaging Waste etc.
• Material
– Glass
– Paper etc.
• Physical Properties
– Compostable
– Combustable
– Recyclable
• Sources
– Domestic
– Commercial
– Industrial
• Safety Level
– Hazardous
– Nonhazardous
classification on
the basis of source
is widely adopted
and is used.
Sources of Solid Wastes
• Agricultural Waste : Waste arising from
agricultural practice.
• Mining Waste: Mainly inert material from mineral
extracting industries.
• Energy Production Waste: Waste from energy
production units including ash from coal burning.
• Industrial Waste: Wastes generated by various
industries.
• Dredging Waste: Organic and mineral wastes from
dredging operations.
• Construction and Demolition Waste: Bricks, brick
•
•
bats, concrete, asphaltic material, pipes etc.
Treatment Plant Waste: Solids from grit chambers,
sedimentation tank, sludge digesters of waste water
treatment plant.
Residential Waste: Garbage including food waste,
paper, crockery and ashes from fires, furniture.
• Commercial Waste: Similar to residential wastes
produced from offices, shops, restaurants etc.
• Institutional Waste: Similar to residential wastes plus
hazardous, explosive, pathological and other wastes which
are institution specific (hospital, research institute etc.)
Hazardous Waste
The waste which can
• Contribute to increase in mortality
• Can cause irreversible illness
• Can pose potential hazard to human health
is called hazardous waste.
Hazardous waste can be classified as
• Radioactive substances
• Chemicals
• Biological Wastes
• Flammable waste
• Explosives
Characteristics of Hazardous Waste
There are four characteristics which make the waste
hazardous category
1. Ignitability
2. Corrosivity if pH  2 or ≥ 12.5
3.Reactivity:- A waste exhibits the characteristics of
reactivity if a representative sample of the waste has
the following properties
• Reacts violently with water
• Forms explosive mixture with water
• When mixed with water, generates toxic gases,
fumes or vapours
• Reacts at a standard temperature or pressure
4. Toxicity:- The limits for
a waste to be toxic for
different contaminants
are shown in the table.
• If the concentration of
a particular constituent
into the ground water
as a result of improper
management exceeds
the above limits, then
it is called as
toxic.
Contaminant Max.
Concentratio
n (mg/l)
Arsenic
5.0
Barium
100.0
Benzene
0.5
Cadmium
1.0
Lead
5.0
Mercury
0.2
Vinyl
chloride
0.2
Municipal Solid Wastes
•MSW refers to all wastes collected by local
authority or municipality and is the most diverse
category of waste.
•Comprises all wastes except agricultural, mining,
energy production and dredging wastes.
Characteristics of Solid Waste
•Solid waste generated by a society may be inert, biologically
active or chemically active.
•Agricultural waste is primarily biologically active. It is generated in
large quantities and remains uniformly dispersed on land surface
area.
•Mining waste is primarily inert and is also generated in large
volumes. However it accumulates continuously at mining sites.
•Industrial wastes
-generated in industrial area
- are highly industry specific.
-usually comprise of chemicals and
allied products, rubber, plastic,
metals, petroleum and coal
products etc.
• MSW is generated at densely populated urban
centres and are most heterogenous.
• Predominant constituents of MSW are paper,
food, wastes, plastics, glass , metals and inert
material.
• In developing country like india, 40% waste is
compostable, 40% inert material
• In developed countries, paper forms a major
part of MSW followed by compostable matter.
The inert material content is low.
Management of Solid waste
There are two fundamental objectives of
solid waste management.
To minimize the waste.
To manage the waste still produced.
Waste Characterization
• - Waste characterization means
finding out how much paper,
glass, food waste, etc. is
discarded in your waste stream
• -Waste characterization
information helps in planning
how to reduce waste, set up
recycling programs, and
conserve money and resources
Solid waste Characterisation
• Physical and chemical composition -vary depending on
sources and types of solid wastes.
• Nature of the deposited waste in a landfill will affect: gas and
leachate production and composition by: -virtue of relative proportions of degradable and nondegradable components,
-the moisture content
-the specific nature of the bio-degradable
element.
• Waste composition will effect both gases and the trace
components.
The important parameters to characterise the waste
are
• Waste composition
• Moisture content
• Waste particle size
• Waste density
• Temperature and pH
These parameters affect the extent and rate of
degration of waste. The typical approximate analysis
for MSW are show below.
Moisture
Volatile matter
Fixed carbon
Glass, metal and ash
20%
53%
7%
20%
• Physical Properties
•
•
•
•
•
•
•
Temperature range and distribution
Insoluble components
Colour
Odour
Foamability
Corrosiveness
Radioactivity
• Flow data for total discharge
• Avg. daily flow rate
• Duration and level of minimum flow rate
• Maximum rate of change of flow rate
Meaningful
characterisation
information can only be obtained
through
proper
analysis
of
representative samples or through the
use of online water quality monitoring
instrumentation.
Chemical Composition
•Organic and inorganic components by compounds or
classes
•COD, Total organic carbon, BOD
•Specific problem ions(As, Bo, Cd, Cr etc.)
•Specific problem organic e.g. phenol, certain pesticides,
benzidine etc.
•Total dissolved salts
•pH, acidity, alkanity
•Nitrogen, Phosphorous
•Oils and greases
•Oxidizing or reducing agents
•Surfactants
•Chlorine demand
Biological Effects
•Biochemical oxygen demand
•Toxicity
•Pathogenic bacteria
Solid Waste Composition
PHYSICAL COMPOSITION
•
•
•
•
•
•
Waste composition
Moisture content
Waste particle size
Waste density
Temperature
pH
CHEMICAL COMPOSITION
1. Proximate analysis
a. Moisture (loss at 1050C for 1 h)
b. Volatile matter (additional loss on
ignition at 9500C)
c. Ash (residue after burning)
d. Fixed carbon (remainder)
2. Fusing point of ash
3. Ultimate analysis, percent of C (carbon)
(hydrogen), O (oxygen), N (nitrogen), S
(Sulphur), and ash
4. Heating value
Chemical Composition
• Important in evaluating alternative processing
and recovery options.
• Wastes can be thought of as a combination of
semi moist combustible and non-combustible
materials.
• If solid wastes are to be used as fuel, the four
most important properties to be known are:
1. Proximate analysis
2. Fusing Point of Ash
• Defined as that temperature at which the ash
resulting from the burning of waste will form a
solid (clinker) by fusion and agglomeration.
• Typical fusing temperature for the formation
of clinker from solid waste range from 2000 to
2200oF (1100 to 1200oC).
3. Ultimate analysis of a waste
• Component typically involves the determination
of the percent C (carbon), H (hydrogen), O
(oxygen), N (nitrogen), S (sulphur), and ash.
• Due to concern over the emission of chlorinated
compounds during combustion, the
determination of halogens also done
• The results of the ultimate analysis are used:
-To characterise the chemical composition of the
organic matter in MSW.
-To define the proper mix of waste materials to
achieve suitable C/N ratios for biological
conversion processes.
Factors Influence Waste Composition:
• Geographical location
• Standard of living
• Energy source
• Weather
Waste Generation Rates
SIGNIFICANCE:
To obtain data that can be used to determine
the total amount of waste
to be managed
- Measure of quantities in terms of weights
Factors Influence Waste Generation Rates:
• Socioeconomic development
• Degree of industrialization
• Climate
• Greater the economic wealth and the higher
percentage of urban population, the greater
the amount of solid waste produced
• Low income countries have the lowest
percentage of urban populations and the
lowest waste generation rates
Other Factors affect Waste Generation Rates:
•
•
•
•
•
•
Geographic location
Season of the year
Frequency of collection
Characteristics of population’
Extend of Recycling
Attitude of people
Methods for determining Waste
Generation Rates
1. Load count analysis
In this method , no: of individual load and
corresponding vehicle characteristics are
noted over a specific period of time
Waste contents are
unloaded for sorting
Appropriate mass of material is
selected randomly
Each load is separated manually by
component example - Wood,
concrete, plastic, metal, etc.
Components are separated
Each component is weighed and
weights recorded
Generated Waste =
Disposed (Collected) Waste +
Diverted Waste
2. Weight – Volume Analysis
• Weighing and measuring each load- provide
information on density of various solid forms
at different volumes
3.Material Balance Analysis
- A system boundary around the unit to be
studied is drawn
- All activities that affect waste generation is
identified
- Rate of waste generation associated with
these activities studied
GROUND WATER CONTAMINATION
1. SOURCES OF GW CONTAMINATION
2. TRANSPORT MECHANISMS IN GW
CONTMINATION ( VERY VERY IMPORTANT)
3. ISOTHERMS
4. EFFECTS OF SOIL CONTAMINATION
STUDY FROM PHOTOSTAT