1. Selection of HCRW Treatment Technologies for Gauteng
David A Baldwin, PhD, Pr.Sci.Nat.
Environmental and Chemical Consultants cc
and
Torben Kristiansen
Chief Technical Advisor. Gauteng Department of Agriculture, Conservation, Environment and Land Affairs
Rambøll, Hanneman and Hojland
August 2003

2. Introduction Status Quo Study into HCRW in Gauteng – 2000:
Confirmed parlous state of HCRW management in Gauteng
Treatment facilities included 70 incinerators at 58 different locations
Only 58 were “operational” but only 25 had a permit
Many incinerators were poorly operated and maintained
Only one fitted with emission control equipment, which was not operational
Capital and operating costs were estimated at only R1.00 per kilogram of waste treated

3. Introduction to Technologies -1
Thermal treatment/combustion technologies:
Incineration which includes:
excess air,
controlled air,
rotary kiln and
fluidised bed
Plasma Arc and
Pyrolysis

4. Introduction to Technologies -2
Sterilisation/Disinfection Technologies,
Steam sterilisation, e.g. Autoclaving
Chemical sterilisation, e.g. with chlorine, glutaraldehyde
Gas sterilisation, e.g. with ethylene oxide, formaldehyde
Dry heat sterilisation, e.g. oil heated screw feed technology
Electro-thermal deactivation (ETD),
Microwave sterilisation,
Irradiation sterilisation
Cobalt-60 gamma rays
Ultra violet
Electron beam sterilisation

5. Waste Pathway for Incineration
Infectious waste & Sharps
Ash
Landfill
Leachate
Flue gas
cleaning residues
Pathological Waste
Incineration
Chemical Waste
Emissions
to Air

6. Waste Pathway for Non-Burn Technologies
Non-infectious waste
Leachate + Gas Emissions
Infectious waste & Sharps
Non-Burn Treatment
Landfill
Incineration
Cremation or Burial
Ash or Body Parts
Pathological Waste
Cemetery
Treatment as Hazardous Waste
Waste Treatment Residues to Landfill
Chemical Waste

7. Flow Diagram of Modern Incineration Plant

8. Advantages of Incineration
Safe elimination of all infectious organisms in the waste at temperatures above ~700oC
Flexible, as it can accept pathological waste and depending on the technology chemical waste.
Residues are not recognisable
Reduction of the waste by up to 95% by volume or 83 to 95% by mass: typically 5-17% ash is obtained.
Very well proven technology
No pre-shredding required
No special requirements for packaging of waste
Full disinfection is assumed to have occurred provided the high temperatures are maintained and the ash quantity is adequate. No monitoring of sterilisation efficiency is required.

9. Disadvantages of Incineration
Normally higher investment costs required for incinerator and flue gas cleaning compared to non-burn technologies
Point source immediate emissions to the air (as opposed to attenuated emission of CH4 and CO2 from landfill body over a period of decades)
High cost of monitoring gas emissions and demonstrating compliance to emission standards.
Solid and liquid by-products must be handled as potentially hazardous waste (may not apply to bottom ash if waste is well sorted and FGC residues handled separately)
Incineration is perceived negatively by many sections of the community.
PVC and heavy metals in the waste provide a significant pollutant load on the gas cleaning system and for heavy metals on the quality of bottom ash
Existing health care risk waste incinerators in South Africa cannot accept significant amounts of chemical waste because of refractory damage.

10. Flow Diagram a Typical Microwave Plant

11. Advantages Non-Burn Technologies -1
Autoclaving, Microwaving ETD and DHS (Cross cutting)
High sterilisation efficiency under appropriate conditions
Low temperature of operation 90oC to 160oC
Volume reduction depending on type of shredding/compaction equipment that has been installed
Low risk of air pollution
Moderate operation costs
Easier to locate as generally more acceptable to communities and neighbours than incineration
Recovery technologies can be used on sterilised waste

12. Advantages Non-Burn Technologies -2
Autoclaving
Proven system that is familiar to health-care providers
Relatively High Sterilisation Temperature
Microwaving
Low capacity units are available for small waste producers e.g. clinics and GPs
Moderate investment costs
Low Sterilisation Temperature may lower energy costs
Electro-thermal Deactivation

13. Disadvantages Non-Burn Technologies -1
Autoclaving, Microwaving ETD and DHS (Cross cutting)
Not suitable for pathological waste and chemical waste
Good waste segregation required
No or limited mass reduction
Shredders are subject to breakdowns and blocking and repairs are difficult when the waste is infectious.
It is not possible to visually determine that waste has been sterilised
Waste is not rendered unrecognisable or unusable, if not shredded
“High” monitoring costs to demonstrate compliance with sterilisation standards
Treated waste must be disposed to landfill
Air filtration is needed – some odour problems
Operation requires highly qualified technicians.
HEPA filters must be maintained and replaced regularly

14. Disadvantages Non-Burn Technologies -2
Autoclaving
Significant amounts of volatile organic carbon compounds produced
Contaminated water must be discharged to sewer
Waste and containers must have good steam permeability, especially if there is no prior shredding
No waste reduction
Microwaving
Unsuitable for very high quantities of infected metal (e.g. needles from inoculation campaigns)
Low sterilisation temperature increases time required for treatment.
Electro-thermal Deactivation
Relatively high investment and operating costs

15. Cost Comparison of Selected HCRW Treatment Technologies - 1
Assumptions:
Salary costs include all normal contributions
The cost for the establishment of a building in the estimated costs.
A standard fixed amount for consultancy fees and other expenditure required to obtain an EIA authorisation, etc
The cost of equipment was based on International/South African price levels for delivery in Gauteng.
Incinerators include gas-cleaning equipment, i.e. lime treatment plus a ceramic filter.
The cost of civil works and installation were based on Gauteng prices

16. Cost Comparison of Selected HCRW Treatment Technologies - 2
Economic life of civil works and treatment technologies: 12 years
Economic life of storage and transportation equipment: 10 years
The following costs not included:
Infrastructure at the generators site,
Establishment of public utilities used, e.g. landfills
Cost of administration, invoicing, marketing etc.
Cost of training of operators
Cost of PPE/OSH programmes.
Value Added Tax.
Depreciation costs are estimated as 10 years for equipment and 15 years for other capital and a real interest rate of 12% p.a.

17. Cost Comparison of Selected HCRW Treatment Technologies - 3
The operational hours for the plants were based on operation for 26 days per month and 12 months per year. However, the maximum operational hours were varied as follows:
Incinerators < 200kg/hr: 12 hrs per day - manual de-ashing
Incinerators  200kg/hr: 20 hours per day - automatic de-ashing
Non-burn Technologies: 24 hours per day
The costs for disposal of residues, such as the ash and gas cleaning waste from incinerators, and sterilised the waste from non-burn technologies, were estimated using current disposal costs. Residues from non-burn are assumed deposited at normal landfill sites, whereas residues from incinerators are assumed deposited at a Hazardous Waste Landfill site.
For non-burn technologies an estimate of the costs of disposal of pathological waste and chemical waste that could not be treated by the technology was included

18. Costs for HCRW Treatment Technologies
Technology
Capacity, kg/hr
Investment Cost, R m
Running Cost, R m*
R/kg
Microwaving
100
5.83
2.33
3.27
7.40
3.10
1.95
10.61
5.09
1.08
Autoclaving
4.84
1.82
3.03
250
6.34
2.55
1.34
9.90
5.14
1.71
Incineration
3.96
1.66
5.55
5.16
2.49
2.00
1000
7.42
4.53
0.97
* Running Costs = Interest + Depreciation on Capital + Operating (monitoring excluded)

19. Cost of HCRW Technologies
Treatment cost decreases dramatically as plant capacity increases
For incineration, there is a discontinuity that occurs below 200kg/hr due to the assumptions made
The costs are based on operating the facility at its maximum capacity.
According to the available data, microwaving is relatively expensive but the costs become comparable at higher loads.
The investment costs for incineration appear to be relatively low compared to the other two technologies.

20. Testing and Monitoring Incineration Plants - 1
Requirements:
Performance Testing – to conform to ROD
Standard Testing – at least over first year of operation
Minimum Programme – once prove conformance
Analysis Required:
Continuous Monitoring of PM, carbon monoxide, oxygen, water vapour, hydrochloric acid and sulphur dioxide
Dioxins: Performance x 1; Standard – 2/yr; Minimum – 1/yr
Metals: Performance x 1; Standard – 2/yr; Minimum – 1/yr
Loss on Ignition for Ash: Performance x 1; Standard and Minimum – 12/yr

21. Testing and Monitoring Incineration Plants - 2
Performance Analysis
Standard Analysis
Minimum Analysis
Capital Cost
R868,000
Depreciation
R1,041,000
Running Cost
R90,000
R370,000
R283,00

22. Testing and Monitoring Incineration Plants - 3
Waste Throughput,
kg/hr
Standard Programme
Minimum Programme
Treatment Cost R/kg
Monitoring Cost as %
100
7.09 22
6.49 14
250
2.37 16
2.22
9.0
500
1.43
8.2
1.36
6.2
1000
1.00
7.0
0.96
4.0