15 Waste minimization, waste hierarchy, waste audit
Dr. Logakanthi S
1. Objectives:
After completing this module, you should be able
- To understand the importance of waste minimization in waste management
- To know about the hierarchy of waste management
- To know the steps involved in waste audit
2.Waste minimization
Certain concepts are fundamental to waste management policy universally. These include waste minimization or prevention, waste hierarchy, life-cycle of a product, resource efficiency and environmentally sound management. Waste minimization refers to strategies that aim to prevent waste at source through upstream interventions (UNEP, 2013). Waste minimization involves redesigning products and/or changing societal patterns, concerning consumption and production, of waste generation, to prevent the creation of waste and minimize the toxicity of waste that is produced (USEPA, 1995). The most effective way to reduce waste is by not creating it in the first place. Some examples of waste reduction include using reusable plates and coffee mugs instead of disposable ones, buying durable products that can be repaired rather than replaced, etc.
2.1. The need for waste minimization
Waste is not only an environmental problem but also an economic loss as these are resources that are not being used. The amount of waste generated is steadily increasing across the world. This can be attributed to a number of factors like change in consumptive patterns of people, economic growth and globalisation etc. The increasing quantity of waste is in turn putting high demand on land as landfill is one of the commonest techniques for tackling waste. However, globally the available land for this purpose is decreasing due to growing population and demand for land for other purposes. Thus, the shrinking land resource is one of the major drivers for waste minimization.
Secondly, the dumpsites or landfill sites have been identified as a major contributor of green house gases thus confirming their positive role in climate change. This in turn is drawing attention to better waste management practices thatemphasize on waste reduction. Thirdly, the cost of waste management is going high. In order to overcome this it becomes essential to target the reduction in waste production, which can be achieved by better production processes. Therefore it can be concluded that the increasing quantity of waste, decreasing availability of landfill site, role of waste in climate change and the high cost of waste management are some of the important drivers for minimizing the quantity of waste.
2.2 Approaches to waste minimization
Having realized the need for minimizing waste the next step would be to explore the ways to achieve this. Waste generation has two sides namely the production side and the consumption side and it is important to work on both the aspects in order to achieve this. At the production side actions must be taken at industrial level, which should include
i. Effective processes for manufacturing products with enhanced materials
ii. Cleaner and safer production
iii. Improved design for reuse, recycle and durability
iv. Resource maximization
v. Reducing the volume of toxic materials
vi. Reduction of production waste
vii. Facilitate recycling
At consumptive level actions must be taken at individual level which should include
i. Increased awareness on impact of waste and role of individuals to tackle the same
ii. Change in consumption behavior and lifestyles
iii. Participation in waste management programs
Box 1.Waste minimization measures that can be taken at individual level
- Home composting: Segregate organic (food waste) at home and compost them to get manure that can be used in kitchen garden and potted plants at home.
- By durable things and maintain them properly so that you don’t have to replace them often (remember your grandparents had TVs and fridges that they used for 25 years)
- Avoid using disposable cutleries and dining ware.
- Carry your own reusable water bottle so as to avoid buying disposable water bottles.
- Carry your own bags while shopping
- Sort the waste at home (newspaper, cartons, bottles, cans etc.) recycle them as much as possible and reduce the waste going to landfill site.
Waste minimization measures that can be taken at institutional level
- Think green while procuring things for institutions like offices, businesses and schools.
- Practice waste segregation and adopt recycling techniques
- Manage cafeteria waste by composting thereby reducing the quantity of waste going to landfill
3. Hierarchy of waste management
The waste management hierarchy indicates an order of preference for action to reduce and manage waste (UNEP, 2013). It is usually represented as an inverted pyramid (Figure 1).
Figure 1.Waste Management hierarchy (UNEP, 2013)
The top of the pyramid is the flat base here (as it is inverted) and it emphasizes foremost on prevention of waste generation. Prevention can be done by using less material during manufacture. Avoiding hazardous material is also a means of prevention. Prevention is also known as reduce This is the first ‘R’ of waste management. The next preferred action is to reduce waste generation through re-use. Reuse refers to materials that can be used again in their original form. This is the second ‘R’ of waste management. Reuse can be done through repair, refurbishing the whole item or its spare parts. Recycling, including composting or anaerobic digestion, is the next preferred action. Recycling is the process of collecting and processing materials that would otherwise be disposed of as waste and turning them into new products. This is the third ‘R’ of waste management. After exhausting these three R’s the waste management looks at materials recovery and waste-to-energy processes. Energy is recovered from processes such as combustion and pyrolysis. The final action, which is represented by the pointed top of the pyramid, is disposal, which is the least preferred option. Landfill and incineration without energy recovery are the disposal options in waste hierarchy. Figure 2. Presents the outputs in different stages of waste management hierarchy. When waste hierarchy is followed it results in good environmental practice.
Waste hierarchy options for paper and board is provided as an example.
Prevention:
- Use less packing material
- Reuse the packaging material.
- Minimize printing and print on both sides
- Reduce paper use by using email
- Use one side printed paper as notepads
The environmental benefits of prevention will reduce green house gas emissions, energy consumption and resource reuse.
Reuse: Segregate and shred paper and sell it. Use one side printed paper as notepads. Reuse reduces the environmental impacts
Recycling: segregate paper from waste, sort by grade and recycle in paper industry. At certain times, energy is also recovered from paper. Recycling saves the energy and minimizes the fossil fuel consumption. Typically twice the amount of energy is saved.
Disposal: If any of the above options does not work properly then the waste paper is compacted or baled to reduce its volume. By doing so the space in the landfill is reduced and the frequency of collection can be minimized. Paper should be avoided in landfills as it emits methane.
4. Waste Audit
For any waste management program to be effective it is essential that accurate information on the quantity and composition of the waste stream be known. A ‘waste audit’ is the first step towards it.
Figure 1: Waste management hierarchy (CIELP, 2008)
Figure 2: Waste management hierarchy along with outputs at each stage (Davidson, 2011)
It is a systematic procedure to review operations and subsequently, waste generation. Information from these audits can help both at household level and organizational level to determine methods of waste reduction. The objectives of a waste audit at organizational level are
- To determine the types of waste and amounts that is being generated
- To identify areas where reduction of waste can be improved
- To determine the effectiveness of any current waste management strategies The steps involved in waste audit are depicted in the figure 3.
Figure 3. Waste audit steps
The first step in waste audit is planning and determining the study area. In case of institutional waste a team with the knowledge of waste together with its source of generation within the organization should be put together. This team can include one or two motivated and responsible people (depending on the size of the organization) from each of the business area like maintenance, cleaning, purchasing, production line etc. The objective of waste audit should be clear to all the members of the team for it to be successful. The team should then walk through the facility to get to know about the types of wastes generated and their location. This will then enable the team members to identify the study area. The second step should be to collect the waste from designated study area. There should be clear instruction regarding the type of waste to be collected for the audit. Protect gear should be worn by the team members for this purpose. After the collection comes the third step, which is sorting. Sorting will enable in analyzing the types and quantity of waste generated by the organization. The quantification of different components in the waste stream can either be done indirectly based on purchase records (i.e., material wasted = material purchased – (material used in product + material unused) or directly by weighing the waste sorted and collected.
The last step is to analyze the data thus collected so as to identify the waste trends and habits of the organization. This can be done using an excel spreadsheet analysis. This is crucial to draw a waste management plan and monitor its implementation. Thus waste audit is a crucial procedure for waste management.
- Summary
This lecture familiarizes about:
- Need for waste minimization
- Approaches to waste minimization
- Hierarchy of waste management
- Waste audit
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- References
- Recommended waste characterization methodology for direct waste analysis studies in Canada, 1999, http://www.ccme.ca/files/Resources/waste/packaging/pn_1497_waste_char.rpt_final_e.pdf
- Annepu, Ranjith Kharvel (2012), Sustainable solid waste management in India, Columbia University, New York Davidson, G. (2011);
- https://www.dal.ca/content/dam/dalhousie/pdf/sustainability/Waste%20Management%20Literature %20Review%20Final%20June%202011%20(1.49%20MB).pdf
- U.S Environmental Protection Agency (1995), Decision-makers’ guide to solid waste management, volume II. Washington http://www.epa.gov/osw/nonhaz/municipal/dmg2/
- United Nations Environmental Program (2013). “Guidelines for National Waste Management Strategies Moving from Challenges to Opportunities”
- http://www.fccenvironment.co.uk/assets/files/pdf/content/wrap-applying-wastehierarchy.pdf