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Chapter 6.7 Transitional technologies

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Evolution of a hazardous waste management system

IMPLEMENTATION & ENFORCEMENT

LEGISLATION

SUPPORTSERVICES

FACILITIES

INSTITUTIONAL ARRANGEMENTS

STAKEHOLDERS

Source: David C Wilson 1993, 1999

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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 systemThen: • Choose the ‘best of the rest’ from around the

world• Adapt these to local needs and circumstances• Build a unique local system

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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

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The implementation conundrum

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

No hazardous waste treatment facilities = no controls over hazardous waste generators

No controls = no waste to treatment facilities

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Taking the first stepsLong 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

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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

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Transitional Technologies used by industrialised countries 1

Source: David C Wilson 1993

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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

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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

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Overcoming the disadvantages of transitional technologies

• Set firm deadlines on use• Segregate wastes• Control after-use• Maintain good operational control• Keep records• Ban imports

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Examples of transitional technologies1 Short term measures

• Export

• Encapsulation

• Solar evaporation

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Examples of transitional technologies2 Low cost longer term measures

•Waste avoidance and minimisation

•Simple chemical treatment

•Fuel blending for cement kiln incineration

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Examples of transitional technologies3 Medium term measures

• Co-combustion in existing furnaces

• Co-disposal in municipal solid waste

landfill sites

• Simple cement-based solidification

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Early measures for waste

minimisation

Source: David C Wilson 1993

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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

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Encapsulation

• Short term option only• Suitable for high hazard waste• Pack securely in metal drums• Cast in fours in metal drums• Label, keep records

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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

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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

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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 non-organic

constituents

Requirements:

– Proper sanitary landfill for MSW

– Good management and control

– Restricted range of acceptable wastes

– Restricted loading rates

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Cement-based solidification

Source: David C Wilson 1990

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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

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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

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Simple physico-chemical treatment - case study

Bangkok treatment facility

Source: David C Wilson

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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

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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

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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