Sustainability and Management : Sustainability – Concept (IAPT equation), needs and challenges –
economic, social and Environmental aspects of sustainability. From unsustainability to sustainability -
millennium development goals and protocols. Concept of Carbon Credit, Carbon Markets and Carbon
Offsets- Basic definitions, creation comparison of carbon credits and Offsets. Zero waste 3R concept and
Circular economy concepts. Material Recovery Facility (MRFs)- Definition, Importance, Classification-
based on technology used and its characteristics: Mixed MRF, Dry MRF, Manual MRF, Semi automatic
MRF, Mechanical MRF/automated MRF; Criteria for Location of MRFs; Constituents in an MRF: Standard
Process Flow of MRF; Unit Processes in MRF; Value chain of MRF.
Sustainability: —meeting the needs of the present generation without compromising the ability of future
generations to meet their needs.
Concept:
To grasp the magnitude of the pressures on resources and ecosystems, it is useful to invoke a conceptual
equation that is generally attributed to Ehrlich and Holdren (1971). The equation relates impact (I) to
population (P), affluence (A), and technology (T):
I = P * A * T
This conceptual relationship, referred to as the IPAT equation, suggests that impacts, which could be
energy use, materials use, or emissions, are the product of the population (number of people), the
affluence of the population (generally expressed as gross domestic product (GDP) of a nation or region,
divided by the number of people in the nation or region i.e. GDP per capita , and the impacts associated
with the technologies used in the delivery of the affluence (impact per unit of GDP).
For example, if the IPAT equation were used to describe energy use in the United States, 'I' would
represent energy use per year, 'P' would represent the population of the United States, 'A' would
represent the annual GDP per capita, and T would represent the energy use per dollar of GDP.
Needs and challenges –economic, social and Environmental aspects of sustainability:
It can be concluded that, nearly everything man does or plans to do on earth has implications for the
environment, economy or society and for that matter the continued existence and wellbeing of the
human race.
The spheres constitute a set of interrelated concepts which should form the basis of human decisions
and actions in the quest for SD. Examples of these include decisions on land use, surface water
management, agricultural practices, building design and construction, energy management, education,
equal opportunities as well as law-making and enforcement. The argument is that, when the concepts
contained in the three spheres of sustainability are applied well to real world situations, everybody wins
because natural resources are preserved, the environment is protected, the economy booms and is
resilient, social life is good because there is peace and respect for human rights.
Economic sustainability: Economic sustainability implies a system of production that satisfies present
consumption levels without compromising future needs.
Traditionally, economists assuming that the supply of natural resources was unlimited, placed undue
emphasis on the capacity of the market to allocate resources efficiently. They also believed that
economic growth would be accompanied by the technological advancement to replenish natural
resources destroyed in the production process.
However, it has been realized that natural resources are not infinite; besides not all of them can be
replenished or are renewable. The growing scale of the economic system has overstretched the natural
resource base, prompting a rethink of the traditional economic postulations. This has prompted many
academicians to question the feasibility of uncontrolled growth and consumption.
Economies consist of markets where transactions occur. There are guiding frameworks by which
transactions are evaluated and decisions about economic activities are made. Three main activities that
are carried out in an economy are production, distribution and consumption but the accounting
framework used to guide and evaluate the economy with regard to these activities grossly distorts values
and this does not augur well for society and the environment.
Human life on earth is supported and maintained by utilizing the limited natural resources found on the
earth. Due to population growth, human needs like food, clothing, housing increase, but the means and
resources available in the world cannot be increased to meet the requirements forever.
The main concern seems to be on economic growth, important cost components like the impact of
depletion and pollution, for example, are ignored while increasing demand for goods and services
continues to drive markets and infringe destructive effects of the environment.
Economic sustainability, therefore, requires that decisions are made in the most equitable and fiscally
sound way possible, while considering the other aspects of sustainability.
Social sustainability: Social sustainability encompasses notions of equity, empowerment, accessibility,
participation, cultural identity and institutional stability. The concept implies that people matter since
development is about people.
Basically, social sustainability connotes a system of social organization that alleviates poverty. However,
in a more fundamental sense, "social sustainability" relates to the nexus between social conditions such
as poverty and environmental destruction. In this regard, the theory of social sustainability' posits that
the alleviation of poverty should neither entail unwarranted environmental destruction nor of economic
instability. It should aim to alleviate poverty within the existing environmental and economic resource
base of the society.
At the social level sustainability entails fostering the development of people, communities and cultures
to help achieve meaningful life, drawing on proper healthcare, education gender equality, peace and
stability across the globe.
Unlike the environmental and economic systems where flows and cycles are easily observable, the
dynamics within the social system are highly intangible and cannot be easily modeled.
"the definition of success within the social system is that "people are not subjected to conditions that
undermine their capacity to meet their needs"
Social sustainability is not about ensuring that everyone's needs are met. Rather, its aims at providing
enabling conditions for everyone to have the capacity to realize their needs, if they so desire. Anything
that impedes this capacity is considered a barrier, and needs to be addressed in order for individuals,
organization or community to make progress towards social sustainability
Social sustainability also encompasses many issues such as human rights, gender equity and equality,
public participation and rule of law all of which promote peace and social stability for sustainable
development.
Environmental sustainability: The concept of environmental sustainability is about the natural
environment and how it remains productive and resilient to support human life. Environmental
sustainability relates to ecosystem integrity and carrying capacity of natural environment.
It requires that natural capital be sustainably used as a source of economic inputs and as a sink for
waste. The implication is that natural resources must be harvested no faster than they can be
regenerated while waste must be emitted no faster than they can be assimilated by the environment.
The effects of climate change, for instance, provide a convincing argument for the need for
environmental sustainability. Climate change refers to significant and long-lasting changes in the climate
system caused by natural climate variability or by human activities. These changes include warming of
the atmosphere and oceans, diminishing ice levels, rising sea level, increasing acidification of the oceans
and increasing concentrations of greenhouse gases. Environmental sustainability is important as it has
implications for how the natural environment remains productively stable and resilient to support
human life and development.
From unsustainability to sustainability -millennium development goals and protocols:
The concept of development:
Development, as a concept, has been associated with diverse meanings, interpretations and theories
from various scholars. Development is defined as 'an evolutionary process in which the human capacity
increases in terms of initiating new structures, coping with problems, adapting to continuous change,
and striving purposefully and creatively to attain new goals.
The sustainable development goals:
Sustainable development relates to the principle of meeting human development goals while at the
same time sustaining the ability of natural systems to provide the natural resources and ecosystem
services upon which the economy and society depend.
While the concept of sustainable development has been relevant since time immemorial, it can be
argued that the relevance deepens with the dawn of every day because the population keeps increasing
but the natural resources available to humankind do not.
Conscious of this phenomenon, global concerns have always been expressed for judicious use of the
available resources. The latest of such concerns translated into the Millennium Development Goals
(MDGs) and the Sustainable Development Goals (SDGs). The MDGs were a sequel to the SDGs. The
MDGs marked a historic global mobilisation to achieve a set of important social priorities worldwide However, in spite of the relative effectiveness of the MDGs, not all the targets of the eight goals were
achieved after being rolled out for 15 years (2000–2015), hence, the introduction of the SDGs to
continue with the development agenda.
The Millennium Development Goals (MDGs) were eight goals adopted by world leaders in 2000:
● Eradicate extreme poverty and hunger
● Achieve universal primary education
● Promote gender equality and empower women
● Reduce child mortality
● Improve maternal health
● Combat HIV/AIDS, malaria, and other diseases
● Ensure environmental sustainability
● Develop a global partnership for development
As part of this new development roadmap, the UN approved the 2030 Agenda (SDGs), which are a call to
action to protect the planet, end poverty and guarantee the well-being of people .
The 17 SDGs primarily seek to achieve the following summarised objectives.
The short titles of the 17 SDGs are: No poverty (SDG 1), Zero hunger (SDG 2), Good health and well-being
(SDG 3), Quality education (SDG 4), Gender equality (SDG 5), Clean water and sanitation (SDG 6),
Affordable and clean energy (SDG 7), Decent work and economic growth (SDG 8), Industry, innovation
and infrastructure (SDG 9), Reduced inequalities (SDG 10), Sustainable cities and communities (SDG 11),
Responsible consumption and production (SDG 12), Climate action (SDG 13), Life below water (SDG 14),
Life on land (SDG 15), Peace, justice, and strong institutions (SDG 16), and Partnerships for the goals
(SDG 17).
Concept of Carbon Credit, Carbon Markets and Carbon Offsets- Basic definitions, creation comparison of
carbon credits and Offsets. Zero waste 3R concept and Circular economy concepts.
Introduction:
Starting in the 1990s with the Kyoto Protocol, governments and multilateral organizations led the way by
creating avenues for countries to participate in carbon reduction efforts through the use of carbon
credits and carbon offsets. The mechanisms introduced by the Kyoto Protocol led to the creation of
global and regional compulsory compliance regimes requiring both countries and corporate entities to
limit their carbon emissions.
The focus on carbon credits as a means of combating climate change is relatively new. The concept of an
international carbon market was first established by the Kyoto Protocol in 1997. Initially signed by 180 countries, the Kyoto Protocol came into effect in 2005, setting legally binding targets for 37 industrialized
countries to limit or reduce their overall greenhouse gas emissions ("GHG Emissions") by an average of
at least 5% below their respective 1990 levels during the period of 2008-2012.
Carbon Credit : Tradable permits that each represent the right to emit one metric ton of carbon dioxide
or other greenhouse gases.
A carbon credit is a tradeable permit, much like a permission slip, that represents an entity's right to
emit one metric ton of carbon dioxide or other greenhouse gases into the atmosphere. Carbon credits
are created and issued by a regulatory body in charge of implementing and overseeing a compliance
market in a particular jurisdiction, such as a cap-and-trade system. Under a compliance market, certain
entities that emit carbon dioxide or other greenhouse gases are legally mandated to participate and
meet the market's emissions limits. These entities are awarded carbon credits that allow them to
continue to emit carbon dioxide up to a certain limit, which is typically reduced periodically. If an entity
maintains its GHG Emissions below the specified limit, it may not need all of the carbon credits it has
been issued. In that case, the entity may sell any excess credits to another entity that needs them.vii
Carbon credits are generally traded in compliance markets.
Carbon Offsets: Like a carbon credit, a carbon offset represents one metric ton of carbon dioxide or
equivalent greenhouse gases. Unlike carbon credits, however, carbon offsets measure the amount of
carbon that has been avoided or permanently removed from the atmosphere. Carbon offsets can be
created by either:
• Avoidance or reduction projects such as renewable energy, methane capture, or other such facilities;
or
• Removal or sequestration projects such as reforestation, direct carbon capture, or similar enterprises.
Most of the demand for carbon offsets comes from entities that have voluntarily set GHG Emissions
reduction targets that can be met either by reducing their own GHG Emissions directly or by effectively
paying someone else to implement measures that reduce GHG Emissions.
While carbon offsets are generally traded in voluntary markets, certain carbon offsets can serve as an
alternative mechanism to meet GHG Emissions caps in compliance markets if such carbon offsets are
approved by the compliance market. Notably, many regulatory schemes permit carbon offsets to be used
to satisfy the requirements of the compliance regime.
The table below summarizes the key distinctions between carbon credits and carbon offsets. [TABLE]
Zero waste: The zero waste concept is a set of principles that aims to reduce or eliminate waste by reusing
and repurposing products and materials.
Reduce waste: Reduce the amount of waste generated
Reuse: Reuse products and materials as much as possible
Recover: Recover resources from waste
Design: Design products to be durable and use fewer materials
Conserve: Conserve resources through responsible production and consumption
Avoid burning: Avoid burning products and materials
Avoid discharging: Avoid discharging products and materials into the land, water, or air
3R concept : 3R approach (reduce, reuse, and recycle), which preliminarily emphasizes the importance of
waste reduction, reuse, and recycling side-by-side with waste processing or management. The adoption
of 3R principles minimizes the amount of waste to be disposed, thereby also minimizing the public
health and environmental risks associated with it. Maximization of resource recovery at all the stages of
solid waste management is advocated by this approach. The 3R Approach is aimed at optimizing waste
management in all the waste generation and management activities, involving all the stakeholders
(waste generators, service providers, informal sector, regulators, government, and community or
neighborhoods). The adoption of 3R minimizes the waste being handled by the ULB (urban Local Body)
and reduces the public health and environmental risks associated with it.
Reduce: The concept of reducing the amount of waste generated by reducing consumption is essential
to waste management hierarchy. The logic behind it is simple to understand – if there is less of waste
generated, then there is less to recycle, reuse or to manage. The process of reducing begins with an
examination of what is being used, what it is used for and by how much it can be reduced. It also
involves modification of processes and packaging; substitution; minimization and elimination.
Reuse: The reuse of items (for multiple times) or repurposing them for a use different from what they
are originally intended for is the next essential thing in the waste reduction hierarchy. Items may be
reused for one's own use (or reuse) or donated so that others can use them so that the gross
consumption of materials is reduced and the waste generation thereof.
Recycle: The last stage of the 3R waste hierarchy is to recycle. Recycling is the transformation of waste
into a raw material for manufacturing a new item. There are very few materials on the earth that cannot
be recycled, hence it is very effective in waste management. Thus, the 3R approach stands at the very top of the waste management hierarchy. The scientific
management of MSW leads to improved public health and quality of life apart from generating jobs,
generating revenue and new products from waste streams.
Circular economy concept:
The circular economy is a system where materials never become waste and nature is regenerated. In a
circular economy, products and materials are kept in circulation through processes like maintenance,
reuse, refurbishment, remanufacture, recycling, and composting. The circular economy tackles climate
change and other global challenges, like biodiversity loss, waste, and pollution, by decoupling economic
activity from the consumption of finite resources.
The circular economy is based on three principles, driven by design:
● Eliminate waste and pollution
● Circulate products and materials (at their highest value)
● Regenerate nature
Material Recovery Facility (MRFs)- Definition, Importance, Classification-
based on technology used and its characteristics: Mixed MRF, Dry MRF, Manual MRF, Semi automatic
MRF, Mechanical MRF/automated MRF; Criteria for Location of MRFs; Constituents in an MRF: Standard
Process Flow of MRF; Unit Processes in MRF; Value chain of MRF.
MRF- Definition: A material recovery facility (MRF) accepts waste materials, whether source segregated
or mixed, and further separates, processes and stores them for later use as raw materials for
remanufacturing, reusing and reprocessing.
The main function of the MRF is to maximize the quantity of recyclables processed, while segregating
materials that will generate the highest possible revenues from the recycling market. MRF also helps in
segregating combustible fraction (RDF- Refuse Derived Fuel- Fuel made from combustible waste),
non-recyclables and inert from the dry waste stream. These fractions may be utilize/reused as –
• Recyclables – Reuse/ reprocessed
• Non-recyclables - Road making/ plastic to oil
• RDF - Waste to Energy/ Cement Industries
• Inert - C&D (Construction and Demolition) plant/ daily cover of SLF (Sanitary Land Fill)
Need of Material Recovery Facility (MRF)
Municipal Solid Waste (MSW) is the trash or garbage that is discarded from various sources i.e.,
Domestic, Commercial, Institutional, Industrial/ Trade etc. in day to day activities. SWM 2016 rules do
not permit disposal of organic matter into sanitary landfills and mandate that only inert rejects (residual
waste) from processing facilities, inert street sweepings, etc. can be landfilled.
All options of waste minimization should be utilized before appropriate treatment technologies are
selected and implemented. With the aim to reduce the amount of waste being finally disposed, and
maximizing resource recovery and efficiency, Material Recovery Facilities (MRFs) need to be established
within the ULBs (Urban local Body).
A Material Recovery Facility (MRF) is an infrastructure to receive, sort, process and store recyclable/ non
recyclables/ RDF and inert materials, with the aim to maximize the quantity of recyclables processed,
while producing materials that will generate the highest possible revenues in the market and maximize
the reuse of other segregated fraction in different processes/ industries.
It is the responsibility of the ULB to set up material recovery facilities with enough space for sorting of
recyclable materials as a follow up of source segregation of waste at-least as Dry and Wet waste in their
SWM. MRFs serve as intermediate processing step between the collection of recyclable materials from
waste generators and the sale of recyclable/ nonrecyclables/ RDF/inert materials to the recycling market
and for other processes and industries .
Advantages of MRF:
Recycling prevents a significant fraction of municipal, institutional and bulk waste from being dumped or
disposed in landfills. It results in the availability of scarce resources as well as reducing environmental
impacts and the burden of waste management on public authorities. If the necessary market
mechanisms are established, recycling can generate revenue, contributing to the cost recovery in the
municipal solid waste service provision. It helps the ULB by reducing waste volumes and results in cost
savings in the collection, transportation and disposal infrastructure, longer life span for landfills/reduced
requirement of land, reduced environmental management efforts and generates livelihood opportunities
for informal, local vendors/recyclers in the recycling industry.
Types of MRF:
Mixed MRF : Unsegregated, mixed waste with biodegradable and non-biodegradable material is
collected and sent to the MRF processing facility. At the mixed MRF, the mixed waste stream may be
segregated manually or mechanically to separate recyclable material from compostable and inert wastes.Compostable matter and recyclable materials may then be processed separately, and residual inert
wastes are sent to the landfill. Receiving mixed waste (recyclable materials combined with other
municipal solid waste) that requires labor intensive sorting activities to separate recyclables from the
mixed waste. The MRF unit can use a combination of manual, hybrid and machine-based sorting .
Dry MRF or Clean MRF: A facility that receives source segregated or commingled recyclable materials
(recyclable materials that are already separated from other main solid waste or wet waste). A "clean"
MRF reduces the material contamination and can recycle more materials than mixed MRFs. Dry
segregated material is received in a commingled form consisting of a combination of paper, cardboard,
magazines, plastics etc. and commingled containers (plastic, glass, metal, etc.), among other materials.
The first stage of processing typically uses manual labor or equipment that separate waste materials into
various streams (metal, paper, plastic, containers, etc.). These recyclables are also sorted by using
automated machines when quantities to be handled are large. Depending on the scale of operations,
type of operations and the level of mechanization in the facility, MRFs may be classified as manual,
semiautomatic or mechanized.
Manual MRF: In manual MRFs, sorting process is carried out manually. This type of MRFs are suitable
for small quantities of MSW like 5-10 TPD only. Sometimes, these Material recovery facilities are also
termed as Solid Liquid Resource Management (SLRM) centers. These SLRM centers received waste either
in mixed form or in wet and dry waste streams. In SLRM centers processing of wet waste can also be
carried out depending upon the land availability and location.
Semiautomatic MRF: This type of Material Recovery Facilities has combination of manual and
mechanized operations. Semi-automated MRF can cater for 10- 100/200 plus TPD of segregated waste.
Semi-automated MRFs also work as secondary collection points in which after segregation of wet & dry
streams, further transportation of MSW is carried out in compacted manner to save on transportation
cost.
Mechanical / Automated MRF: Mechanized material recovery facilities are fully mechanized/
automated facilities for material recovery in large quantities (>100 TPD) with least human intervention.
These facilities are best suitable for segregation of recyclables/non-recyclables/ RDF/inert, when only
source segregated dry waste is coming to the facility. These mechanized plants have limitations to
segregate mix MSW if the wet/ mix waste is more than 20% of the total received waste.
Selection of MRF: The configuration of MRF processing line is critical to the overall quality of the
materials segregated. It depends on several factors including the quality and quantity of incoming waste
(segregated or mixed) and required specifications for the end products and also the land available.
Selection of MRF depends largely on ULBs capabilitiesits financial conditions and its linkage to market/
industries for sale of byproducts. It is pertinent to note that every given the specific conditions, every
ULB has requirement of tailormade types of MRFs. ULBs have to adopt the type of MRF as per their
specific requirement depending upon the following aspects: • Waste Quantity
• Waste characterization
• Availability of land
• Capital and Operational cost of facility (including cost of Manpower)
• Provisions/ Linkages for sale of recyclables and by products
• Type and linkage of final treatment/disposal facility
Sitting (Location) Criteria for MRF:
Ideally the MRF shall be located close to both the source of the MSW generation and the industries that
will use the recycled materials since the minimization of travel distances is important for reducing costs.
In order to be located near the residential areas, the facility must be both environmentally and
aesthetically acceptable. A buffer space with trees / shrubs will help improve aesthetics and decrease
any noise pollution.
• MRFs need to be located close to existing roads, but traffic blocks resulting from the movement of
waste collection trucks should be considered and avoided.
• These facilities must be near or within urban areas that generate the inputs to be processed for
recyclables.
• If the development area is zoned, MRFs are preferably located in an industrial zone or close to a
sanitary landfill to facilitate efficient movement of waste from various generators and disposal of residual
waste.
• MRFs should be sited, considering the local geographical features, in a safe manner
• Flood-prone areas should not be selected.
Constituents in an MRF can be as follows:
• MRF is situated within a warehouse-type building with concrete flooring and enclosed by a perimeter
fence for security.
• It should have the following components:
• Weighing scale / Weighbridge
• Changing/Washroom/Rest rooms and creche, as required
• Receiving or tipping area
• Sorting/processing area
• Storage area for recyclables
• Residual storage area
• Admin/ Record room/First Aid Room
• Fire Extinguishing facilities
• It should also be provided with the basic connections for water and electricity and with adequate space
for the entry and exit of waste transporting vehicles.
Provisions for toilet/ change/washrooms must be included.
• The warehouse design should minimize the placement of columns that could interfere with the
efficient movement of materials and equipment and should facilitate the installation of higher ceilings.
• Receiving areas should have the capacity to receive at least 2 days' waste storage space for the MRF's
processing capacity in anticipation of equipment breakdown and to provide materials for the
second-shift operation, if required.
Standard Process Flow of MRF
[TABLE]
Unit Processes in MRF:
The MRFs employ varying combinations of manual and mechanical processes, based on the type of
facility, availability of equipment and labour, and associated cost implications.
MRFs employing manual labour for sorting operations have relatively lower costs but may operate at
lower efficiencies compared with mechanical sorting facilities.
An MRF, depending on the level of complexity, will consist of a combination of processing units in varying
degrees of mechanization:
(a) Pre-sorting: Waste sorting or processing in the facility through manual or mechanical presorting is
essential to separate out these bulky/ large pieces and packets of wastes. Manual sorting results in
higher labour costs and lower processing rates. Manual sorters remove bulky waste as the waste passes
along a conveyor belt, which carries the pre-sorted waste to the mechanized sorting unit of the facility.
Mechanical, bulky waste sorters are also used in semi automated and automated MRFs.
(b) Mechanical sorting: Mechanical processes based on principles of electromagnetics, fluid mechanics,
pneumatics, etc. are used to segregate the different waste streams in the pre-sorted waste. Mechanical
processes require specialized equipment for segregation of commingled municipal waste. Mechanical
sorting typically employs the following processes:
1) Screening: Screening achieves an efficient separation of wastes into two or more size distributions.
Two types of screens are used in MRFs- disc screens and trommels.
2) Ferrous metal separation: In the second stage, electromagnets are used for separating ferrous metals
from mixed waste.
3) Air classification: The residual waste stream is passed through an air stream with sufficient velocity to
separate light materials from heavy material, specifically for separating out lightweight plastics and
paper from the mixed stream. Three types of air classifiers may be employed: (i) horizontal air classifier,
(ii) vibrating incline air classifier, and (iii) incline air classifier. Heavy or bulky plastics are sorted out either
in the pre-processing line (manually) or in the "detect and routing" systems, employed at later stages of
material recovery.
4) Non-ferrous metal separation: The nonferrous metal separator segregates zinc, aluminium, copper,
lead, nickel, and other metals from commingled waste. An eddy current separator removes non-ferrous
items from the waste based on their electrical conductivity.
5) Segregation of non-recyclables and Combustibles: Segregation of nonrecyclables and combustibles
fractions can be done manually / mechanically to enhance the efficiency and earning of facilities.
6) Optical system (sensor based): This system separates various grades of paper, plastics, and glass,
which are not sorted out in the air classifier. This system works in two stages. The first stage employs
programmed optical sensors to determine the nature of different materials. In the second stage, based
on information received from the sensor, sorted material is routed to appropriate bins by directional air
jets.
7) Size reduction: Sorted materials after segregation, if large for further use or processing and should be
reduced to smaller sizes.
8) Baling: Sorted & sized materials are baled for further processing or use.
Typical value chain in MRF
[TABLE]