Lecture 1 - Key concepts in solid waste management policy and systems (Ch. 1.1-1.2)

Question 1

What is the definition of wastes according to the Basel Convention?

Answer 1

“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 the law”

Question 2

What is the definition of waste according to The Waste Framework Directive (DIRECTIVE 2008/98/EC)?

Answer 2

‘waste’ means any substance or object which the holder discards or intends or is required to discard.

Question 3

What is the definition of waste according to the textbook by Christensen, 2010?

Answer 3

“Waste is a left-over, a redundant product or material of no or marginal value for the owner and which the owner wants to discard.”

Question 4

How circular is the global economy?

Answer 4

5-7%

Question 5

How is solid waste defined?

Answer 5

Solid wasteis mostly in a solid state, but also sludge from wastewater treatment and liquid chemical waste are in its scope.

excluded are: water (wastewater) and air borne (flue gasses).

Question 6

The solid waste can be divided in two important groups. Which?

Answer 6

Hazardous vs. non-hazardous

• Important to distinguish because of practical reasons (different treatment) and regulatory aspects
• Waste may be hazardous because of
• Specific properties: explosive, oxidizing, toxic, carcinogenic, infectious (medical waste)

Question 7

How is waste defined by EU?

Answer 7

Once a substance or object has become waste, it will remain waste until it has been fully recovered and no longer poses a potential threat to the environment or to human health

Question 8

Mention the three historical drivers for environmental policy and specifically waste management policy.

Answer 8

• Reduce impacts on Human Health
• Reduce negative environmental impacts
• Create an Energy and Ressource efficient economy.

Question 9

In EU 28, ca. 2,5 billion tonnes of waste are produced anually. How much does MSW make up of this?

Answer 9

ca. 10%

Question 10

What is the definition of backfilling?

Answer 10

It means any recovery operation where suitable non- hazardous waste is used for purposes of reclamation in excavated areas or for engineering purposes in landscaping. Waste used for backfilling must substitute non-waste materials, be suitable for the aforementioned purposes, and be limited to the amount strictly necessary to achieve those purposes.

Question 11

Why is MSW important to handle?

Answer 11

Because of its characteristics: complexity, biological activity etc.

Question 12

How much MSW is on average generated per capita per day on a global scale?

Answer 12

The world generates 0.74 kg of municipal waste per capita per day (range 0.11 to 4.54)

Estimated at over 2 Gt/y and projected to increase to 4-5 Gt/y by 2100

Around 44% is food waste and green waste

Question 13

How did the following conventions and protocols contribute to waste management?

• The Basel Convention
• The Montreal Protocol
• The Kyoto Protocol
• The Aarhus Convention
• The Paris Agreement

Answer 13

• The Basel Convention (22 March 1989; UNEP, 1989) provides an international regulation on hazardous waste export and transport
• The Montreal Protocol (16 January 1987; UNEP, 2000) limits the use of chlorinated and fluorinated compounds in consumer products and restricts the emission of these compounds because of their ability to deplete stratospheric ozone
• The Kyoto Protocol (11 December 1997; UN, 1998) commits countries that ratify the protocol to reduce their emissions of greenhouse gases or engage in emission trading
• The Aarhus Convention (25 June 1998; UNECE, 1998) focusses on public participation, human rights and links government accountability by environmental protection.
• The Paris Agreement (4 November 2016)

Question 14

Which role do the state and country level play in waste management?

Answer 14

National or state authorities create the framework for the municipalities, which are the main decision-makers in waste management in most Western countries. The framework may contain:

• specific goals to be achieved (e.g.recycling goals),
• specific guidelines as to how planning is done or how facilities should be constructed and operated

State and county often are the approving authority that shall assess and license specific facilities, privately as well as publicly owned. At the state level, taxescan be introduced to economically force waste management towards certain desirable goals.

Question 15

Which role do the muncipalities and regions play in waste management?

Answer 15

Municipalities often have the responsibility to establish systems for waste management including a range of services with sufficient capacity. Municipalities (and sometimes the State) make the concrete decision on source separation as well as treatment and disposal facilities: type, capacity, location. Consequently, they also have the financial responsibility and power to collect fees for using the waste management system.

Question 16

Which role do producers and individual industries and citizens play in the waste management?

Answer 16

As a basic principle, the producer of the waste is responsible for its management until the waste and the responsibility for its management are transferred to an authorized entity, e.g.the municipality or a licensed private company. This transfer is at the cost of the waste producer.

Question 17

How does the waste hierarchy look like?

Answer 17

1. Prevention (product) –> Lowering the amount of waste produced.
2. (preparing for) Reuse –> Using products or components again for the same purpose they were built
3. Recycling –> Material recovery followed by reprocessing into products with the original or other purposes
4. Recovery –> Energy recovery from waste
5. Disposal –> Safe disposal of waste, e.g. controlled landfilling.

Question 18

Explain “the polluter pays principle”

Answer 18

The party responsible for generating the waste has to pay for it’s subsequent treatment and/or environmental damage

Question 19

Explain “Extended producer responsibility”

Answer 19

Producers of certain goods are responsible for their proper treatment at end-of-life, post-consumer wise –e.g. electronic and electric products and in the near future also packaging products

Question 20

Mention examples on disposal and which enviromental impacts it has.

Answer 20

Landfilling and incineration without energy recovery.

Associated with many potential environmental impacts even with a modern design:

• methane air emissions (25 times more potent greenhouse gas than CO2)
• Heavy metals (Cd, Pb, Hg, others) release with leachate that can contaminate ground water and soil
• Discharge of solids into water bodies, e.g. plastics

Valuable resources and potential energy in the waste are lost.

Question 21

Mention examples on recovery methods

Answer 21

Thermal treatment of waste for energy recovery

• Waste incineration
• Pyrolysis and Gasification

Biological treatment

• Biogas (digestion) and biofuels (fermentation) from waste
• Composting with land application

Question 22

How much heat and electricity does incineration of 1 tonne waste generate?

Answer 22

2 MWh heat

2/3 MWh electricity

Question 23

Which method is used for cleaning/avoid air emissions from incineration?

Answer 23

Sophisticated flue gas cleaning ensures very limited air emissions

Question 24

Mention examples on recycling. What are the benefits of recycling?

Answer 24

• Home segregated (source separated) waste fractions like paper and glass are recycled into the same products
• Deposit systems ensure recycling of packaging materials
• Material sorting and recovery in large central sorting facilities (metals, paper, plastics)
• End-of-life product waste streams (electronics, batteries, cars)

Benefits:

• Resource savings
• Huge energy savings compared to production from raw materials (energy in the material + energy invested to extract/produce it)

Question 25

Give examples on reuse

Answer 25

• Bottle return, washing and refilling
• Refurbishing of different products (electronics, ink cartridges)
• Reuse of components (end of life cars)

Question 26

Give examples on prevention

Answer 26

• Design of less wasteful products: increase life time, eco-design
• Better balance and coordination between supply and demand
• Encouragement of reuse and repair
• Cleaner production technologies

Question 27

Mention some waste management principles

Answer 27

Life Cycle Thinking and Life Cycle Assessment:

• LCA is a comprehensive accounting system that makes it possible to evaluate alternatives according to defined environmental criteria.
• The EU Waste Framework Directive -> life cycle thinking should be introduced in all waste management decision-making, and derogation from the waste hierarchy should be based on life cycle thinking.

Environmental Economics:

• Prices are estimated for all environmental emissions from a system and added to the traditional economical data for the system.
• Costs distributed in time are discounted, suggesting that future costs associated with waste management have less weight than today’s cost
• Often emissions in foreign countries are not included

Question 28

Which phases do waste management include?

Answer 28

Collection, transport, recovery and disposal of waste

Question 29

What is the characteristics of a unmanaged waste handling system?

Answer 29

• Characteristic for developing countries
• Involves an informal sector
• Cherry picking of materials with value and uncontrolled dumping of the rest

Question 30

What is the characteristics of a industrial waste management system?

Answer 30

Often dealt case-by-case by mostly a private sector (it is not the direct responsibility of public authorities)

Question 31

What is the characteristics of hazardous waste management?

Answer 31

Specialized handling systems, governed by specific rules for collection, storage, transport and treatment

Question 32

What is the characteristics of a municipal waste system?

Answer 32

Organized handling of municipal waste which is the responsibility of public authorities.

Management on behalf of the public authorities can be both by public or private entities.

Question 33

What is the characteristics of a extended producer responsibility system?

Answer 33

Organized handling of specific types of waste, which is the responsibility of the producers/distributers (defined already at product level)

Question 34

Mention the three main treatment technologies/areas regarding MSW

Answer 34

Mechanical treatment:
- Materials Recovery Facilities
  • Sieving
  • Size reduction
  • Ballistic separation
  • Air classification
  • Magnetic and Eddy current separation
  • Advanced sensor-based sorting

Thermal treatment:
• Waste incineration
• Pyrolysis
• Gasification

Biological treatment:
• Anaerobic digestion
• Aerobic stabilization
• Composting

Question 35

Waste characterization is important for several reasons. Mention the policy-related, recycling-related and design-related reasons for doing waste characterization.

Answer 35

Policy related
‒ Provide data on quantities and composition for statistics for policy setting on recycling
‒ Classify waste (hazardous / non-hazardous) for how to treat it

Recycling related
‒ Document adherence to specific quality criteria for recycled materials
‒ Determine efficiency of an introduced recycling scheme

Planning and design related
‒ Determine waste generation rates for forecasting
‒ Characterize waste quantity and composition for design of a waste incinerator

Question 36

Explain the terms used in waste characterization:
• Waste categories
• Waste types 
•Waste quantities (unit?)
• Unit generation rates (unit?)
• Material fractions
• Substances

Answer 36

• Waste categories
–Residential, commercial, industrial …

• Waste types
–Subclasses of the categories (e.g., residential bulky waste)

•Waste quantities
–Normally by wet weight (kg), sometimes by volume (m3)

• Unit generation rates
–kg/year/person; kg/week/household; kg/year/employee; kg/year/m2
kg/1000 Euros of sales …

• Material fractions
–Paper, plastics, glass, organic …

• Substances
–Water, protein, ash content, nitrogen, cadmium …

Question 37

Explain the importance of MFA and mass balances in waste management.

Answer 37

• Analytical methods to quantify flows and stocks of materials or substances in a well-defined system
• Fundamental basis for managing waste in a consistent, environmentally sound and efficient way
• The level of details in a mass balance of a system is a compromise between what is needed to obtain a sufficient understanding of the system and the availability of data.

Question 38

Explain the importance of energy budgets in waste management.

Answer 38

• Energy is used to make the waste management system work and the waste management system itself may generate or save energy
• The energy content of waste itself is significant: 1.0 t of municipal waste may correspond to 0.2 t of crude oil or 0.4 t of coal

Question 39

Which types of emission accounts is used?

Answer 39

Direct emissions: process-specific and input-specific, use of fuels

Indirect emissions: upstream and downstream activities

• upstream activities (e.g. production of electricity used at the facility)
• downstream activities (e.g. savings in industry due to use of scrap metal recovered from waste)

Question 40

What does “Waste engineering” refer to?

Answer 40

Waste engineering here means the skills and ability to understand quantitatively how a waste management system works in such a detail that waste management can be planned, facilities can be designed and sited and systems can be operated in a way that is environmentally sound, technical feasible, economically efficient and socially acceptable.

Question 41

Mention the four phases of waste management:

Answer 41

1. Generation
2. Collection and transport.
3. Treatment
4. Recycling-Utilization-Landfilling

Question 42

What is a Unit Process Inventory?

Answer 42

The unit process inventory (UPI) is a schematic presentation of a technology in terms of its required inputs, generated
outputs and any use or production of energy, as well as any emissions associated with the technology.

For a waste management system, UPIs should be available for all significant upstream processes (e.g. electricity used), the waste management processes themselves (e.g. composting) and all significant downstream processes (e.g. recycled paper substituting for virgin production of waste).