'Wastes' are substances or objects, which
are disposed of or are intended to be disposed of or are required to be
disposed of by the provisions of national law.1
Impacts of Waste Generation
Effects on the environment: Waste
results in accumulation of greenhouse gases (GHGs) primarily Carbon
Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O) which are
responsible for global warming and climate change. CO2 is released into
the atmosphere by the burning of solid waste. CH4 is emitted from the
decomposition of organic waste in landfills. NO2 is emitted during
combustion of solid waste. Rising global temperatures are expected to
raise sea levels and change precipitation and other local climate
conditions. Scientists predict that there is likely to be an overall
trend towards increased precipitation and evaporation, more intense rainstorms
and drier soil. Changing regional climates are expected to alter
forests, crop yields and water supplies. This could also affect human
health, animals and many types of ecosystems. Deserts might expand into
existing rangelands and features of some of our national parks might be
Effects on health: Waste creates
toxicity and chemical poisoning through chemical inhalation resulting in
low birth weight, cancer, congenital malformations, neurological
Effects on flora and fauna: Waste
degrades water and soil quality. It breaks down in landfills to form
methane, a potent source of greenhouse gas which is very harmful to
flora and fauna.
Classification of wastes
The waste generated can be classified in
different ways based on various factors like origin, biocompatibility,
hazardous behavior etc.
According to source/origin:
Municipal solid waste includes household
garbage, rubbish, construction & demolition debris, sanitation residue,
packaging materials etc.
Bio-medical waste includes solid or liquid
waste including intermediate or end products generated during diagnosis,
treatment and research activities of medical science.
Industrial and mining waste includes liquid
and solid waste that is generated by manufacturing and processing units
of various industries like chemical, petroleum, coal, metal gas, paper
Agricultural waste is waste that is
generated from farming activities which is mostly biodegradable.
Fishery waste is waste generated due to
fishery activities. These are extensively found in coastal & estuarine
Radioactive waste is waste containing radioactive materials. Usually
these are byproducts of nuclear processes. Sometimes industries that are
not directly involved in nuclear activities, may also produce some
radioactive wastes, e.g. radio-isotopes, chemical sludge etc.
E-waste is electronic waste i.e. discarded
electrical or electronic devices generated from any household, office or
establishment. Some electronic scrap components, such as CRTs, may
contain contaminants like Pb, Cd, Be or brominated flame retardants.
According to biocompatibility:
Bio-degradable waste is waste that can be
decomposed naturally (paper,
wood, fruits, natural organic substances etc.)
Non-biodegradable waste cannot be decomposed
naturally (plastic, old machines made of iron and steel, styrofoam etc.)
According to their effects on human
health and environment:
Hazardous wastes are substances unsafe to
use industrially, agriculturally, or economically and have properties
like ignitability, corrosivity, reactivity and toxicity.
Non-hazardous wastes are substances safe to
use industrially, agriculturally or economically and do not have any of
the properties mentioned above.
National and Global Scenarios of Waste
Current global municipal solid waste
generation levels are approximately 1.3 billion tonnes per year and are
expected to increase to approximately 2.2 billion tonnes per year by
2025. This represents a significant increase in per capita waste
generation rate, from 1.2 to 1.42 kg per person per day in the next
fifteen years. However, global averages are broad estimates only as
rates vary considerably by regions, countries and even within cities.
MSW generation rates are usually influenced
by economic development, degree of industrialisation, public habits and
local climate. Generally, higher the economic development and rate of
urbanisation, the greater is the amount of solid waste produced. Income
level and urbanisation are highly correlated. With increasing disposable
incomes and living standards, consumption of goods and services
correspondingly increases, as does the amount of waste generated. Urban
residents produce about twice as much waste as their rural counter
Nearly 62 million tonnes of total waste is
generated annually in India.3 Out of this, plastic waste is
5.6 million tonnes, biomedical waste is 0.17 million tonnes, hazardous
waste is 7.90 million tonnes and e waste is 1.5 million tonnes.
Consequently, per capita waste generation in Indian cities ranges from
200 grams to 600 grams per day. MoEF has also forecasted that waste
generation will increase from 62 million tonnes to about 165 million
tonnes by 2030.
Utilisation of waste
Waste management is the process by which
waste products emerging from daily human activities are collected,
segregated and then processed. Human activities in a day produce a large
amount of waste. Waste should be managed effectively to preserve the
environment and protect natural resources.
Recycling is an integral part of any waste
management system as it represents a key utilisation alternative for
reuse and energy recovery. Reuse requires a minimum functionality that
reconditioning can be accomplished within certain costs and time limits.
Recycling only requires a single material waste stream of acceptable
purity and a WTE facility is able to process any waste for energy
recovery as long as it is not contaminated with hazardous substances. To
meet these requirements the different waste streams (e.g., municipal
solid waste, industrial waste, pharmaceutical waste, etc.) must be
treated differently. The rise or fall of a waste management system
highly depends on the support of the residents and employees. They take
the first step in a long chain of processes by separating their waste
stream in direct reusable or recyclable waste streams (e.g., paper,
plastics, glass, etc.) and waste that can be used as a fuel for energy
recovery. Solid waste management rules have been revised by MoEF. The
concept of partnership with Swachh Bharat has been introduced. Bulk and
institutional generators, market associations, event organisers, hotels
and restaurants have been made directly responsible for segregation and
sorting the wastes in partnership with local bodies.
Life-Cycle Assessments (LCA) can help to
decide whether it is sustainable either to reuse or recycle certain
waste streams or to recover the energy only. LCA is a comparative
methodology used to determine the environmental impact and energy or
resource consumption of products and services over their whole life
cycle (extraction of the raw materials, production of the product
itself, use of the product and treatment after disposal as waste). Any
utilisation strategy that consumes more resources and energy or has a
greater environmental impact than the initial production from primary
raw materials is considered 'non-sustainable'. In order to achieve
higher resource efficiency, significant efforts have been made to
utilise various mining and industrial wastes as raw material for
building products. The area of waste-utilisation has thus revealed a new
dimension of modern scientific research.
Palas Kumar Haldar
1 United Nations Environment Programme
2 Urban Development Series-Knowledge Papers
3 Ministry of Environment and Forest, 2016
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