Chapter 6.7
Transitional technologies
TRP Chapter 6.7 1
Evolution of a hazardous waste
management system
INSTITUTIONAL
ARRANGEMENTS
LEGISLATION
IMPLEMENTATION
& ENFORCEMENT
FACILITIES
SUPPORT
SERVICES
STAKEHOLDERS
Source: David C Wilson 1993, 1999
TRP Chapter 6.7 2
How to begin developing a
hazardous waste management
system?
First:
• Understand how HWM systems are put together
• Compare and contrast different national
approaches
• Understand the existing local system
Then:
• Choose the ‘best of the rest’ from around the
world
• Adapt these to local needs and circumstances
• Build a unique local system
TRP Chapter 6.7 3
How easy will the journey be for a
developing economy?
Advantage:
ability to learn from
experience and
mistakes of
industrialised countries
in last 20-25 years
Disadvantages:
•lack of funds
•lack of awareness
•lack of skills
•lack of infrastructure
TRP Chapter 6.7 4
The implementation conundrum
No hazardous waste treatment facilities
= no controls over hazardous waste
generators
No controls = no waste to treatment
facilities
High costs exacerbate problem
eg Hong Kong facility cost >US $150 million
Finance:
•beyond capacity of most governments in developing economies
•needs to come from private sector or international lending body
•needs government assurance
TRP Chapter 6.7 5
Taking the first steps
Long lead time: timeframe between recognising
problem and having treatment and disposal facility
for hazardous wastes is 5-10 years
Need to win political support for:
•
•
•
•
•
imposing extra burden on industry
siting facility
carrying out EIA
obtaining planning permission
dealing with local opposition (not-in-my-back-yard or
NIMBY syndrome)
It is better to do something now than to investigate
for too long
TRP Chapter 6.7 6
Useful first steps
•
•
•
•
•
•
•
Document and quantify problem
Designate and train responsible staff
Control water pollution and solid wastes
Introduce interim treatment/disposal measures
Address early measures for waste minimisation
Raise public/political awareness
Obtain appropriate independent advice
TRP Chapter 6.7 7
Transitional Technologies used by
industrialised countries 1
Source: David C Wilson 1993
TRP Chapter 6.7 8
Transitional technologies used by
industrialised countries 2
No longer available:
•dumping at sea
•incineration at sea
•export to developed countries for treatment
and disposal - increasingly more difficult
under the terms of the Basel Convention
•co-disposal of hazardous wastes with
municipal solid wastes
•already banned in many countries
•being phased out under the terms of EU
Landfill Directive
TRP Chapter 6.7 9
Advantages of transitional
technologies
•
•
•
•
•
Identification of waste generators
Raised awareness
Improved information for planning
Experience for managers and control staff
Reduced temptation to dispose improperly
TRP Chapter 6.7 10
Overcoming the disadvantages of
transitional technologies
•
•
•
•
•
•
Set firm deadlines on use
Segregate wastes
Control after-use
Maintain good operational control
Keep records
Ban imports
TRP Chapter 6.7 11
Examples of transitional technologies
1 Short term measures
• Export
• Encapsulation
• Solar evaporation
TRP Chapter 6.7 12
Examples of transitional technologies
2 Low cost longer term measures
•Waste avoidance and minimisation
•Simple chemical treatment
•Fuel blending for cement kiln incineration
TRP Chapter 6.7 13
Examples of transitional technologies
3 Medium term measures
• Co-combustion in existing furnaces
• Co-disposal in municipal solid waste
landfill sites
• Simple cement-based solidification
TRP Chapter 6.7 14
ste
Early measures
for waste
minimisation
TRP Chapter 6.7 15
Source: David C Wilson 1993
Export (to a developed country)
Only acceptable:
•In the short term
•On a small scale
•To properly managed and operated
‘high tech’ facilities
Example: PCBs for high temperature
incineration from Middle East to UK
TRP Chapter 6.7 16
Encapsulation
•
•
•
•
•
Short term option only
Suitable for high hazard waste
Pack securely in metal drums
Cast in fours in metal drums
Label, keep records
TRP Chapter 6.7 17
Solar evaporation
• Useful for drying aqueous sludges
• Use depends on climate and season
• Strictly as short term option, in isolated areas
under controlled conditions, has been used for
small quantities of volatile organic solvents eg
Arabian desert
TRP Chapter 6.7 18
Co-combustion in existing
industrial furnaces
•
•
•
•
•
Beware air pollution problems
Do not use in domestic boilers
Do not use in cooking
Use in industrial boilers with care
Best option is use in cement kiln
TRP Chapter 6.7 19
Co-disposal
• Controlled mixing of selected hazardous wastes
in sanitary landfill
• Aims at biodegradation of organic constituents
in hazardous waste
• Can also attentuate concentrations of nonorganic constituents
Requirements:
– Proper sanitary landfill for MSW
– Good management and control
– Restricted range of acceptable wastes
– Restricted loading rates
TRP Chapter 6.7 20
Cement-based solidification
Source: David C Wilson 1990
TRP Chapter 6.7 21
Cement-based solidification case studies
Brisbane, Australia:
Simple solidification in clay cells at a landfill site
• facility in operation since 1982
• solidification of liquid hazardous wastes with fly ash and
cement kiln dust
• wastes treated in clay cells in a separate area at landfill
Cape Town, South Africa:
Incorporation of tetraethyl lead (TEL) sludges in concrete
• special precautions to protect workers
• blended concrete used for road on landfill site
• process carried out during dry summer months
TRP Chapter 6.7 22
Simple physico-chemical
treatment
• Physico-chemical treatment is part of a long-term
solution
• Technologies are simple and cost-effective
• Easy to operate and maintain
• Simplest plants use batch operation
• GOOD TRAINING AND SUPERVISION ARE
ESSENTIAL
TRP Chapter 6.7 23
Simple physico-chemical
treatment - case study
Bangkok treatment
facility
Source: David C Wilson
TRP Chapter 6.7 24
Co-combustion in cement kilns
• Can be used as interim treatment method while
dedicated waste treatment facilities being developed, as
well as a long term solution
• Useful in countries with established cement industry,
operational cement kilns
• Offers reduced fuel costs for cement production
• Large capacity
• Suited for various waste types
Constraints:
• lack of trained personnel
• concerns of cement kiln operators
• cost and sophistication of trial burns
• lack of detailed technical data on each facility
• anxiety about accident risks
• about accident risks
TRP Chapter 6.7 25
How to move from transitional
solutions to long term ones
•Ensure the use of short and medium term
solutions are brought to an end by
imposing a time limit
•Tighten permit conditions gradually
•Use landfill fees to fund new technologies
•Make sure the public is aware of the issues
•Landfill has a strategic role during the
transition
TRP Chapter 6.7 26
Chapter 6.7 Summary
• Developing an integrated hazardous waste
management system is complex, takes time,
money and political support
• Developing economies have advantages and
disadvantages, but need to start somewhere
• Transitional technologies offer solutions but have
drawbacks
• Some are short term, some medium term
• Some longer term, but low cost
• Need to move gradually from transitional
technolgies to long term ones
TRP Chapter 6.7 27