Solid waste management (SWM) is the collection,
transportation, processing, disposal or recycling and
monitoring of the solid wastes.
The objectives of solid waste management
are –
1. to identify the different sources, nature
and volume of solid wastes in an area
2. to identify any potential environmental
impacts from the generation of waste in
that area
3. to categorise waste material where
practicable for disposal considerations
4. to recommend appropriate waste
handling and disposal measures
5. to recommend recycling and reuse ,
where ever applicable
6. to encourage energy generation from
the wastes and sustainable development
Municipal
solid waste
(MSW)
Biomedical Hazardous
wastes wastes
Types
of solid
wastes
Agricultural Industrial
wastes wastes
E waste (electronic waste)
As per the e-waste management guidelines provided by
Government of India, definition of e-waste is as follows -
“E-waste comprises of wastes generated from used
electronic devices and household appliances which are not
fit for their original intended use and are destined for
recovery, recycling or disposal. Such wastes encompass
wide range of electrical and electronic devices such as
computers, Executive Summary 7 hand held cellular
phones, personal stereos, including large household
appliances such as refrigerators, air conditioners etc.”
Items and their toxic components
COMPONENTS CONSTITUENTS
Printed circuit boards Lead & cadmium
Cathode ray tubes (CRTs) Lead oxide & Cadmium
Switches & flat screen monitors Mercury
Computer batteries Cadmium
Capacitors and transformers Poly Chlorinated Bi-phenyls (PCB)
Printed circuit boards, plastic Brominated Flame Retardant casings cable
Cable insulation/coating Poly Vinyl Chloride (PVC)
Rapidly increasing volume of e-waste
Low level of awareness of the hazards of incorrect disposal
Widespread e-waste recycling in informal sector using rudimentary
techniques leads to severe environmental damage and health hazards
Recyclers recover precious metals and improperly dispose off the rest.
Moreover, inefficient recycling processes result in substantial loss of
material value
Absence of proper mechanism for Collection of e-waste material and its
proper disposal techniques
Effective recycling processes through technologically sound systems involve
initial investment
Huge gap between generation & recycling of E-Waste
Lack of producer responsibility for take back of products, at the end of its
useful life.
Biomedical waste
Waste generated during the diagnosis, testing, treatment, research or production
of biological products for humans or animals (WHO)
Sources of biomedical waste:
Hospitals , health care centers, research
centers, blood banks, medical college,
dentist’s clinic, animal houses, vaccination
centers etc.
Biomedical waste management :
Characterization
Quantification
Segregation
Storage
Transportation
Treatment
Disposal
Recycling is the process of collecting and processing materials
that would otherwise be thrown away as trash and turning them
into new products. It is a key component of modern waste
management is the third component of the "Reduce, Reuse, and
Recycle"
Benefits :
It reduces the amount of waste sent to landfills and
incinerators and saves energy
It Prevents pollution by reducing the need to collect new
raw materials and conserves natural resources (like timber,
water and minerals)
It creates job opportunities in various manufacturing and
recycling industries.
Methods of solid waste disposal -
1. Composting - Composting is a
biological process in which micro-
organisms, mainly fungi and bacteria,
convert degradable organic waste into
humus like substance.
Advantages of composting –
It helps the in retaining more
nutrients in the soil and providing all
the elements essential for growth of
plants
It helps reduce the adverse effects of
excessive alkalinity, acidity, or the
excessive use of chemical fertilizer and
enrich the soil
It prevents soil erosion
2. Sanitary Landfill –
The waste is spread out in thin layers and compacted. When the landfill is completed, it is
capped with a layer of clay or a synthetic liner in order to prevent water from entering. A
final topsoil cover is placed, compacted, and graded, and various forms of vegetation may
be planted in order to reclaim otherwise useless landIn modern sanitary landfills, covered
with an impermeable liner, usually several layers of clay, thick plastic and sand and
sometimes with some impermeable synthetic liner.
Leachate from bottom is pumped and sent for treatment. Wells are drilled near the landfill site to
monitor if any leakage is contaminating ground water. Methane produced by anaerobic
decomposition is collected and burnt to produce electricity or heat.
Advantages of sanitary landfill –
It is a cost effective method for disposal of solid waste
Landfill gas can be used for the generation of energy
Proper monitoring of the disposal method can be done
Disadvantages of sanitary landfill –
Ground water contamination
Soil contamination
Improper landfilling may lead to growth of vectors such as flies, mosquitoes, rats
etc.
While selecting the sanitary landfill site…..
It should be above the water table, to minimize interaction with
groundwater
Avoid using sand, gravel pits, rock quarry to to prevent high
leeching
Avoid using flood plain as sanitary landfill sites. Most garbage
tends to be less dense than water, so if the area of the landfill
floods, the garbage will float to the top and wash away
downstream.
3. Incineration
A waste disposal method which involves the combustion of organic substances. Incineration of
waste materials converts the waste into ash , flue gas and heat.
Advantages
It is useful for disposal of residue of
both solid waste management and
solid residue from waste water
management
Disadvantage –
It is a costly method for disposal of
solid waste
4. Pyrolysis
Pyrolysis is a form of incineration that chemically decomposes organic materials by heat in
the absence of oxygen. Pyrolysis typically occurs under pressure and at operating
temperatures above 430 °C (800 °F).
Disadvantages
This technique requires drying of soil prior
to treatment
Limited performance data are available for
systems treating hazardous wastes
containing polychlorinated biphenyls
(PCBs), dioxins, and other organics
This method is not effective in either
destroying or physically separating in
organics from the contaminated medium
When the off-gases are cooled, liquids
condense, producing an oil/tar residue and
contaminated water. These oils and tars
may be hazardous wastes, requiring proper
treatment, storage, and disposal
