10.0 Waste Processing.ppt 9881KB Mar 29 2010 05:00:29 AM
10 – Waste Processing
10 Waste Processing
1
10 – Waste Processing
Outline
Outline
10.1 Overview and objectives of waste processing
techniques
10.2 Waste sorting
10.3 Composting
10.4 Reuse and recycling
10.5 Mechanical and Biological treatment
10.6 Incineration
10.7 Land filling
2
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
10.1 Overview and objectives of
waste processing techniques
3
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
Objectives
• to reduce the hazardous nature of the waste
• to separate the waste into its individual components, some
or all of which can then be put to further use/treatment
• to reduce the amount of waste which has to be finally sent
for disposal
• to transform the waste into a useful material
4
10 – Waste Processing
Waste
reception
Intermediate
storage
10.1 Overview and objectives of waste
processing techniques
Treatment
Storage
Disposal
5
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
6
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
Waste processing techniques
• Biological treatments and some mechanical-biological
treatments
• Physico-chemical treatments
• Treatments applied to waste in order to enable the
recycling/regeneration of materials
• Treatments applied to turn a waste into a material that can
be used as a fuel in different industrial sectors
• End-of-pipe techniques used in waste treatment
installations for the abatement of emissions
7
10.2 Waste sorting
10 – Waste Processing
10.2 Waste sorting
8
10 – Waste Processing
10.2 Waste sorting
Process by which waste is separated into
different elements
•
•
•
Manually at the household and collected through
kerbside collection schemes
Automatically separated in materials recovery facilities
Mechanical - Biological treatment systems
9
10 – Waste Processing
10.2 Waste sorting
Biodegradable waste components
•
•
•
Green waste
Kitchen waste
Paper
Other recyclable components
•
•
•
•
Plastics
Glass
Metals (ferrous and non-ferrous)
Co-mingled recyclables
10
10.2 Waste sorting
10 – Waste Processing
Kerbside collection of recyclable resources
Purer waste streams
Higher market value
11
10 – Waste Processing
10.2 Waste sorting
Kerbside collection of recyclable resources
Completely environmentally friendly
BUT
Increased number of
waste collection
vehicles on the
road
?
Global warming
through exhaust
emissions
12
10 – Waste Processing
10.3 Composting
10.3 Waste composting
13
10 – Waste Processing
10.3 Composting
Atoms and molecules
Living systems consist of atoms and
molecules (at the Angstrőm level):
• Carbon (C),
• Hydrogen (H),
• Oxygen (O),
• Nitrogen (N),
• Phosphorus (P),
• Sulphur (S), …..
Groups of atoms make up living and
non-living materials
14
10 – Waste Processing
10.3 Composting
Example living materials:
human being, animals, plants, trees
Example non-living materials:
bricks, metal, stone, oxygen, water
Photosynthetic systems obtain their energy from the sun
CO2 + nutrients + sunlight energy organic mater
Non-photosynthetic systems degrade energy-rich
molecules for their growth
15
10 – Waste Processing
10.3 Composting
Organic matter such as sugar: C6H12O6
16
10 – Waste Processing
10.3 Composting
Aerobic decomposition of biodegradable
organic matter, producing compost
Performed primarily by facultative and obligate aerobic
bacteria, yeasts and fungi, helped in the cooler initial
and ending phases by a number of larger organisms,
and other families representing ants, nematodes and
oligochaete worms
17
10 – Waste Processing
10.3 Composting
Compost pile
From: Starbuck, 2001
18
10 – Waste Processing
10.3 Composting
19
10 – Waste Processing
10.3 Composting
Organisms decomposing organic matter
From: Starbuck, 2001
20
10 – Waste Processing
10.3 Composting
•
A biodegradable material is capable of being broken
down completely under the action of microorganisms
into carbon dioxide, water and biomass
•
A compostable material biodegrades substantially
under composting conditions, into carbon dioxide,
methane, water and compost biomass
•
A compost-compatible material does not have to be
compostable or even biodegradable, is generally inert
and is present in compost at relatively low levels
21
10 – Waste Processing
10.3 Composting
C : N ratio
Carbon e.g. in the form of cellulose which the bacteria need
for their energy (dry, straw-type material, such as
cereal straws, leaves, sawdust, wood chips, paper,
cardboard)
Nitrogen in the form of protein, which provides nutrients for
the energy exchanges (green plant material such as
crop residues, hay, grass clippings, weeds, manure of
poultry, herbivorous animals such as horses, cows and
llamas; fruit and vegetable trimmings)
22
10 – Waste Processing
10.3 Composting
Active
•
•
exothermic action of the bacteria as they decompose
the organic matter
close to ideal conditions
Passive
•
•
level of physical intervention is kept to a minimum
more common type of composting in most domestic
garden compost bins
23
10 – Waste Processing
10.3 Composting
Home composting
range of techniques, from extremely passive (throw
everything in a pile and leave it for a year or two) to
extremely active (monitor the temperature, turn the pile
regularly, adjust the ingredients over time).
Industrial composting
waste management alternative to landfills, along with other
advanced waste processing systems
combined with mechanical sorting of mixed waste streams
is called mechanical biological treatment
24
10 – Waste Processing
10.4 Reuse and Recycling
25
10 – Waste Processing
10.4 Reuse and Recycling
Materials Recovery Facility (MRF)
Specialized plant that receives, separates and prepares
recyclable materials for marketing to end-user
manufacturers.
26
10 – Waste Processing
10.4 Reuse and Recycling
Clean:
accepts recyclable materials that have been collected in
comingled wastes from kerbside collection
separated at source from municipal solid waste
generated by either residential or commercial
sources
Dirty:
accepts a mixed solid waste stream and then proceeds
to separate out designated recyclable materials
through a combination of manual and mechanical
sorting
27
10 – Waste Processing
10.4 Reuse and Recycling
Recycling in The Netherlands
Facts and figures
•
Landfills are used for less than 10% of all waste. Dutch
household waste recycling averages to 60% (2006).
•
Compost (2003): The separately gathered organic
fraction is 50% of household waste, or 1500
kilotonnes. This is processed to 600 kilotonnes of
compost
•
Paper (2005): In the Netherlands the recycled amount
in 2005 was up to 2.5 million tonnes, which is 75% of
annual consumption.
28
10 – Waste Processing
10.5 Mechanical and Biological Treatment
10.5 Mechanical and Biological
Treatment
29
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Biological treatment
uses living micro-organisms to decompose organic wastes
into water, CO2 and simple inorganics or into simpler
organics such as aldehydes and acids
30
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Several biological treatments
31
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Activated sludge:
Decomposes organic wastes in water
by exposing waste to biological
growth. Water is recycled and
aerated to facilitate biological
action and a sludge is generated.
32
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Aerated lagoons:
Large lagoons containing high concentrations of microorganisms. The lagoon is aerated to encourage bacterial
growth and decomposition of waste.
33
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Composting:
‘Engineered’ mounds of waste are built to encourage the
biological breakdown of organic solids, producing a humic
substance valuable as soil conditioner
34
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Aerobic digestion:
Reduction of the organic content of waste. Applied to solid
waste, non-continuous waste waters, bioremediation
and to sludge and soil contaminated with oil
Anaerobic digestion:
Decomposes organic matter in closed vessels in the
absence of air. Uses two forms of bacteria: acidforming and methane- forming. Applied to solid-liquid
wastes, highly contaminated waste waters (e.g.
chlorinated compounds), bioremediation and in the
production of biogas to be used as a fuel.
35
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Mechanical Biological Treatment
Form of waste processing facility that combines a sorting
facility with a form of biological treatment such as
composting or anaerobic digestion
Typical mechanical elements: factory style conveyors,
industrial magnets, eddy current separators, trommels,
shredders and other tailor made systems
36
10.6 Incineration
10 – Waste Processing
10.6 Incineration
37
10 – Waste Processing
10.6 Incineration
Waste treatment technology that involves the combustion
of organic materials and/or substances, "thermal
treatment".
Converts the waste into ash, flue gases, particulates, and
heat, which can in turn be used to generate electricity.
Flue gases are cleaned for pollutants (particulate matter,
heavy metals, dioxins, furans, sulphur dioxide, and
hydrochloric acid) before they are dispersed in the
atmosphere
38
10 – Waste Processing
10.6 Incineration
Types of incinerator plant design
•
•
•
•
moving grate
fixed grate
rotary-kiln
fluidised bed
39
10 – Waste Processing
10.6 Incineration
Gaseous emissions
•
•
•
Dioxin and furans
Carbon dioxide
Other emissions, including sulphur dioxide,
hydrochloric acid, heavy metals and fine particles
40
10 – Waste Processing
10.6 Incineration
Flue gas cleaning
•
•
•
•
•
Electrostatic precipitators (ESP) and/or baghouse
filters
Acid gas / basic scrubbers
Dry desulfurisation
Catalytic reduction (SCR) or selective non-catalytic
reduction (SNCR)
Adsorbtion on active carbon powder
41
10 – Waste Processing
10.6 Incineration
Solid outputs
•
•
•
Fly ash and bottom ash
Fly ash constitutes more of a potential health hazard
High concentrations of heavy metals such as lead,
cadmium, copper and zinc as well as small amounts of
dioxins and furans
42
10 – Waste Processing
10.6 Incineration
Flue gas cleaning
NEUTREC® flue gas cleaning process (from www.neutrec.com)
43
10.7 Landfilling
10 – Waste Processing
10.7 Landfilling
The presentation on landfilling is
provided in chapters 18, 19 and 20
44
10 Waste Processing
1
10 – Waste Processing
Outline
Outline
10.1 Overview and objectives of waste processing
techniques
10.2 Waste sorting
10.3 Composting
10.4 Reuse and recycling
10.5 Mechanical and Biological treatment
10.6 Incineration
10.7 Land filling
2
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
10.1 Overview and objectives of
waste processing techniques
3
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
Objectives
• to reduce the hazardous nature of the waste
• to separate the waste into its individual components, some
or all of which can then be put to further use/treatment
• to reduce the amount of waste which has to be finally sent
for disposal
• to transform the waste into a useful material
4
10 – Waste Processing
Waste
reception
Intermediate
storage
10.1 Overview and objectives of waste
processing techniques
Treatment
Storage
Disposal
5
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
6
10 – Waste Processing
10.1 Overview and objectives of waste
processing techniques
Waste processing techniques
• Biological treatments and some mechanical-biological
treatments
• Physico-chemical treatments
• Treatments applied to waste in order to enable the
recycling/regeneration of materials
• Treatments applied to turn a waste into a material that can
be used as a fuel in different industrial sectors
• End-of-pipe techniques used in waste treatment
installations for the abatement of emissions
7
10.2 Waste sorting
10 – Waste Processing
10.2 Waste sorting
8
10 – Waste Processing
10.2 Waste sorting
Process by which waste is separated into
different elements
•
•
•
Manually at the household and collected through
kerbside collection schemes
Automatically separated in materials recovery facilities
Mechanical - Biological treatment systems
9
10 – Waste Processing
10.2 Waste sorting
Biodegradable waste components
•
•
•
Green waste
Kitchen waste
Paper
Other recyclable components
•
•
•
•
Plastics
Glass
Metals (ferrous and non-ferrous)
Co-mingled recyclables
10
10.2 Waste sorting
10 – Waste Processing
Kerbside collection of recyclable resources
Purer waste streams
Higher market value
11
10 – Waste Processing
10.2 Waste sorting
Kerbside collection of recyclable resources
Completely environmentally friendly
BUT
Increased number of
waste collection
vehicles on the
road
?
Global warming
through exhaust
emissions
12
10 – Waste Processing
10.3 Composting
10.3 Waste composting
13
10 – Waste Processing
10.3 Composting
Atoms and molecules
Living systems consist of atoms and
molecules (at the Angstrőm level):
• Carbon (C),
• Hydrogen (H),
• Oxygen (O),
• Nitrogen (N),
• Phosphorus (P),
• Sulphur (S), …..
Groups of atoms make up living and
non-living materials
14
10 – Waste Processing
10.3 Composting
Example living materials:
human being, animals, plants, trees
Example non-living materials:
bricks, metal, stone, oxygen, water
Photosynthetic systems obtain their energy from the sun
CO2 + nutrients + sunlight energy organic mater
Non-photosynthetic systems degrade energy-rich
molecules for their growth
15
10 – Waste Processing
10.3 Composting
Organic matter such as sugar: C6H12O6
16
10 – Waste Processing
10.3 Composting
Aerobic decomposition of biodegradable
organic matter, producing compost
Performed primarily by facultative and obligate aerobic
bacteria, yeasts and fungi, helped in the cooler initial
and ending phases by a number of larger organisms,
and other families representing ants, nematodes and
oligochaete worms
17
10 – Waste Processing
10.3 Composting
Compost pile
From: Starbuck, 2001
18
10 – Waste Processing
10.3 Composting
19
10 – Waste Processing
10.3 Composting
Organisms decomposing organic matter
From: Starbuck, 2001
20
10 – Waste Processing
10.3 Composting
•
A biodegradable material is capable of being broken
down completely under the action of microorganisms
into carbon dioxide, water and biomass
•
A compostable material biodegrades substantially
under composting conditions, into carbon dioxide,
methane, water and compost biomass
•
A compost-compatible material does not have to be
compostable or even biodegradable, is generally inert
and is present in compost at relatively low levels
21
10 – Waste Processing
10.3 Composting
C : N ratio
Carbon e.g. in the form of cellulose which the bacteria need
for their energy (dry, straw-type material, such as
cereal straws, leaves, sawdust, wood chips, paper,
cardboard)
Nitrogen in the form of protein, which provides nutrients for
the energy exchanges (green plant material such as
crop residues, hay, grass clippings, weeds, manure of
poultry, herbivorous animals such as horses, cows and
llamas; fruit and vegetable trimmings)
22
10 – Waste Processing
10.3 Composting
Active
•
•
exothermic action of the bacteria as they decompose
the organic matter
close to ideal conditions
Passive
•
•
level of physical intervention is kept to a minimum
more common type of composting in most domestic
garden compost bins
23
10 – Waste Processing
10.3 Composting
Home composting
range of techniques, from extremely passive (throw
everything in a pile and leave it for a year or two) to
extremely active (monitor the temperature, turn the pile
regularly, adjust the ingredients over time).
Industrial composting
waste management alternative to landfills, along with other
advanced waste processing systems
combined with mechanical sorting of mixed waste streams
is called mechanical biological treatment
24
10 – Waste Processing
10.4 Reuse and Recycling
25
10 – Waste Processing
10.4 Reuse and Recycling
Materials Recovery Facility (MRF)
Specialized plant that receives, separates and prepares
recyclable materials for marketing to end-user
manufacturers.
26
10 – Waste Processing
10.4 Reuse and Recycling
Clean:
accepts recyclable materials that have been collected in
comingled wastes from kerbside collection
separated at source from municipal solid waste
generated by either residential or commercial
sources
Dirty:
accepts a mixed solid waste stream and then proceeds
to separate out designated recyclable materials
through a combination of manual and mechanical
sorting
27
10 – Waste Processing
10.4 Reuse and Recycling
Recycling in The Netherlands
Facts and figures
•
Landfills are used for less than 10% of all waste. Dutch
household waste recycling averages to 60% (2006).
•
Compost (2003): The separately gathered organic
fraction is 50% of household waste, or 1500
kilotonnes. This is processed to 600 kilotonnes of
compost
•
Paper (2005): In the Netherlands the recycled amount
in 2005 was up to 2.5 million tonnes, which is 75% of
annual consumption.
28
10 – Waste Processing
10.5 Mechanical and Biological Treatment
10.5 Mechanical and Biological
Treatment
29
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Biological treatment
uses living micro-organisms to decompose organic wastes
into water, CO2 and simple inorganics or into simpler
organics such as aldehydes and acids
30
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Several biological treatments
31
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Activated sludge:
Decomposes organic wastes in water
by exposing waste to biological
growth. Water is recycled and
aerated to facilitate biological
action and a sludge is generated.
32
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Aerated lagoons:
Large lagoons containing high concentrations of microorganisms. The lagoon is aerated to encourage bacterial
growth and decomposition of waste.
33
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Composting:
‘Engineered’ mounds of waste are built to encourage the
biological breakdown of organic solids, producing a humic
substance valuable as soil conditioner
34
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Aerobic digestion:
Reduction of the organic content of waste. Applied to solid
waste, non-continuous waste waters, bioremediation
and to sludge and soil contaminated with oil
Anaerobic digestion:
Decomposes organic matter in closed vessels in the
absence of air. Uses two forms of bacteria: acidforming and methane- forming. Applied to solid-liquid
wastes, highly contaminated waste waters (e.g.
chlorinated compounds), bioremediation and in the
production of biogas to be used as a fuel.
35
10 – Waste Processing
10.5 Mechanical and Biological Treatment
Mechanical Biological Treatment
Form of waste processing facility that combines a sorting
facility with a form of biological treatment such as
composting or anaerobic digestion
Typical mechanical elements: factory style conveyors,
industrial magnets, eddy current separators, trommels,
shredders and other tailor made systems
36
10.6 Incineration
10 – Waste Processing
10.6 Incineration
37
10 – Waste Processing
10.6 Incineration
Waste treatment technology that involves the combustion
of organic materials and/or substances, "thermal
treatment".
Converts the waste into ash, flue gases, particulates, and
heat, which can in turn be used to generate electricity.
Flue gases are cleaned for pollutants (particulate matter,
heavy metals, dioxins, furans, sulphur dioxide, and
hydrochloric acid) before they are dispersed in the
atmosphere
38
10 – Waste Processing
10.6 Incineration
Types of incinerator plant design
•
•
•
•
moving grate
fixed grate
rotary-kiln
fluidised bed
39
10 – Waste Processing
10.6 Incineration
Gaseous emissions
•
•
•
Dioxin and furans
Carbon dioxide
Other emissions, including sulphur dioxide,
hydrochloric acid, heavy metals and fine particles
40
10 – Waste Processing
10.6 Incineration
Flue gas cleaning
•
•
•
•
•
Electrostatic precipitators (ESP) and/or baghouse
filters
Acid gas / basic scrubbers
Dry desulfurisation
Catalytic reduction (SCR) or selective non-catalytic
reduction (SNCR)
Adsorbtion on active carbon powder
41
10 – Waste Processing
10.6 Incineration
Solid outputs
•
•
•
Fly ash and bottom ash
Fly ash constitutes more of a potential health hazard
High concentrations of heavy metals such as lead,
cadmium, copper and zinc as well as small amounts of
dioxins and furans
42
10 – Waste Processing
10.6 Incineration
Flue gas cleaning
NEUTREC® flue gas cleaning process (from www.neutrec.com)
43
10.7 Landfilling
10 – Waste Processing
10.7 Landfilling
The presentation on landfilling is
provided in chapters 18, 19 and 20
44