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GENERIC TREATMENT TECHNOLOGIES FOR HEALTHCARE WASTE
Jorge EmmanuelJorge EmmanuelInternational Experts’ WorkshopInternational Experts’ WorkshopUNEP-DTIE-IETCJuly 19-20, 2012Osaka, Japan
TYPES OF TREATMENT TECHNOLOGIES (BY DISINFECTION PROCESS)
Thermal
Temperature
Chemical
Concentration
Irradiative
Radiation dose
Biological
MICROBIAL INACTIVATION
STAATT criteria for healthcare waste
Minimum requirement: Level III Reduction of vegetative bacteria, fungi,
lipophilic/hydrophilic viruses, parasites, mycobacteria by 6 Log or greater
Reduction of heat resistant spores by 4 Log or greater
Microbiological indicators Geobacillus stearothermophilus or Bacillus atrophaeus
spores
Mycobacterium phlei or Mycobacterium bovis
GENERIC TECHNOLOGIES
Information in the Compendium for each Generic Technology
Process DescriptionDiagram or sketchTypes of Waste TreatedRange of CapacitiesPathogen DestructionEmissions and By-ProductsOperational Details Installation RequirementsMaintenance Requirements
GENERIC TECHNOLOGIES
ThermalAutoclavesHybrid autoclavesContinuous steam treatment
systemsBatch microwaveContinuous microwaveFrictional heatingDry heatIncineration and related technologies
GENERIC TECHNOLOGIES
Autoclaves based on design
JacketedRetort
VacuumNon-vacuum
VacuumAir
Filter
Pressure Gauge
Safety Valve
Release Valve
Jacket
Autoclave Chamber
Charging Door
SteamSteam Trap
Steam Trap
Drain
Thermocouple
GENERIC TECHNOLOGIES
AutoclavesRange of capacities:
20 liters to over 20,000 liters per cycle (1 to 2700 kg/hr)
Parameters: 121 to 135 ºC 104 to 212 kPa gauge Exposure time Number of cycles Depth of vacuum
Low maintenance (except for door gasket)Lowest cost
GENERIC TECHNOLOGIES
Autoclaves (based on operation)
Pressure pulse
Pressure gravity (steam flush)
Vacuum pulsing
Pressure vacuum
Pre-vacuum autoclaves
Gravity displacement
GENERIC TECHNOLOGIES
Autoclave without shredding
Autoclave with shredding
GENERIC TECHNOLOGIES
Hybrid Autoclaves
Incorporate internal shredding, fragmentation, and mixing into the autoclave
Common types:
Rotating autoclaves
Autoclaves with internal shredders
Autoclaves with internal mixing arms
GENERIC TECHNOLOGIES
Hybrid AutoclavesBetter steam penetration, shorter
exposure timeHigher maintenance requirements
than autoclavesHigher costs than autoclavesRange of capacities:
38 liters to 21,800 liters (18 to 21,800 kg/hr)
Types of waste treated:Same as autoclave but also including anatomical waste
GENERIC TECHNOLOGIES
Continuous Steam Treatment Systems
GENERIC TECHNOLOGIES
Continuous Steam Treatment Systems
Range of capacities:100 to over 1000 kg/hr
Types of waste treated:Same as autoclave but also including anatomical waste
Higher maintenance requirements than autoclaves and hybrid autoclaves
Higher costs than autoclaves and hybrid autoclave
GENERIC TECHNOLOGIES
Microwave Technology
Magnetrons used to generate microwave energy at 2450 MHz frequency
Two types
Batch
Continuous
Two types based on design
Low pressure, low temperature (95 -100 ºC)
High pressure, high temperature (121, 135 ºC)
GENERIC TECHNOLOGIES
Batch Microwave Unit
Range of capacities:
30 to 210 kg/hr
Types of waste treated:
Same as batch autoclaves but some systems cannot handle sealed glass bottles with liquids and sharp metals not in containers
Low maintenance
Higher cost than batch autoclaves
microwavegenerator
wastebin
controls
GENERIC TECHNOLOGIES
Continuous Microwave Unit
lid
hopper
shredderwastebin
automaticloader
microwavegenerators
holdingtankmicrowave section
outletauger
air treatment system used when the lid is opened
GENERIC TECHNOLOGIES
Continuous Microwave Unit
Range of capacities:
100 to 250 kg/hr
Types of waste treated:
Same as hybrid autoclaves and continuous steam treatment system
Higher maintenance compared to batch autoclaves and batch microwaves; similar to continuous steam treatment
Higher cost than batch autoclaves and batch microwaves
GENERIC TECHNOLOGIES
Frictional Heating Systems
“New kid on the block”
Uses both saturated steam and dry superheated steam
Heat to generate steam comes from heaters and from frictional heat due to high speed rotors operating at 1000 to 2000 rpm (about 15-30 rps)
Result is a dry powder
GENERIC TECHNOLOGIESFrictional Heating Systems
Range of capacities:
10 to 500 kg/hr
Types of waste treated:
Same as hybrid autoclaves and continuous steam or microwave treatment systems
Typical cycle
time
T ºC
100
GENERIC TECHNOLOGIES
Frictional Heating Systems
Vapor exhaust to air filters
Sterilization chamber with high
speed rotor blades
Electrical panel
Discharge bin
Lid
GENERIC TECHNOLOGIES
Dry Heat Systems
Mainly natural or forced convection (hot air) and conduction from electrical resistance heaters
Range of capacities:
0.2 to 10 kg/hr
Types of waste treated:
Same as autoclaves
Intended for small facilities
GENERIC TECHNOLOGIES
Incineration
Range of capacities:
10 kg/hr to over 20 tonnes per day
Types of waste treated:
In addition to infectious waste, properly designed incinerators can handle pathological, laboratory chemical and pharmaceutical wastes
Historically common types of incinerators:
Dual-chamber incinerators
Multiple-chamber incinerators
Rotary kilns
GENERIC TECHNOLOGIES
Dual-chamber incinerator
Primary Combustion Chamber
Secondary Combustion Chamber Air Pollution Control System
To Stack
Ram Feed
Ash SumpPrimary Burners
Secondary Burner
GENERIC TECHNOLOGIES
Multi-chamber excess air incinerator
GENERIC TECHNOLOGIES
Rotary kiln
Hopper
Rotary Kiln
Ram or Auger Feeder
Secondary Combustion Chamber
Ash Sump
Gas Scrubber
Venturi Quench
Dry Chemical
Baghouse Fabric Filter
ID Fan
Packed Tower-
Demister
Stack
GENERIC TECHNOLOGIES
Other types of incinerators
Fluidized bed incinerators (generally not used with medical waste)
Stepped hearth incinerators
Moving grate or reciprocating grate (stoker) incinerators
Vertical combustors
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Incinerator Design
An incinerator should consist of: Furnace or kiln (primary combustion
chamber) Afterburner chamber (secondary chamber) Flue gas cleaning system Wastewater treatment if wet flue gas
cleaning is used
BAT air emissions performance level: 0.1 ng I-TEQ/Nm3 at 11% oxygen
BAT wastewater performance level for effluents from treatment of gas treatment scrubbers:
0.1 ng I-TEQ/liter
To be achieved by a suitable combination of primary and secondary measures
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Primary measures
Introduction of waste at 850ºC or higher; automation to avoid introducing waste below 850ºC
Avoidance of temperatures below 850ºC and no cold regions
Auxiliary burners Avoidance of starts and stops Control of oxygen input
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Primary measures
Minimum residence time of 2 seconds at 1100ºC in the secondary chamber after last addition of air and 6% O2 by volume (for waste with >1% halogenated substances)
High turbulence of exhaust gases and reduction of excess air
On-line monitoring for combustion control and regulation from a central console.
Temperature, oxygen, carbon monoxide, dust
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Secondary measures
Dedusting
Fabric filter operating below 260ºC
Ceramic filter used between 800 to 1000ºC
Cyclones for pre-cleaning
Electrostatic precipitators around 450ºC
High performance adsorption units with activated carbon
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Secondary measures
Techniques for further emission reduction
Catalytic oxidation
Gas quenching
Catalyst-coated fabric filters
Different types of wet or dry adsorption systems using mixtures of activated charcoal, coke, lime and limestone solutions
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Disposal of Residues (bottom and fly ash)
Ash should be handled, transported (using covered hauling) and disposed of in an environmentally friendly manner
Catalytic treatment or vitrification of fabric filter dusts
Disposal in safe dedicated landfills (e.g., landfilling in double-walled containers, solidification, or thermal post-treatment)
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
Monitoring
Routine monitoring of: CO, oxygen, particulate matter, HCl, SO2, NO2, HF, air flows, temperatures, pressure drops, and pH
Periodic or semi-continuous measurement of: polychlorinated dioxins and furans
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
General measures
Operation by trained, qualified personnel
Use of personal protection equipment
Periodic maintenance including cleaning of the combustion chamber and declogging of air flows and fuel burners
Auditing and reporting systems
Routine inspections of the furnace and air pollution control systems by the regulatory authorities
BAT REQUIREMENTS UNDER THE STOCKHOLM CONVENTION
EXAMPLES OF OTHER ENVIRONMENTAL REQUIREMENTS
Pollutant Units US EPA emission limits EU emission limits
Small Medium Large Daily average
0.5-hour average
0.5-8 hour average
Particulates mg/m3 50 17 14 10 10, 30
CO mg/m3 18 1.6 9.8 50 100, 100
Dioxins/furans ng TEQ /m3 0.0099 0.011 0.027 0.1
HCl mg/m3 17 8.9 5.9 10 10, 60
SO2 mg/m3 2.8 2.8 16 50 50, 200
Mercury mg/m3 0.011 0.0027 0.00099 0.05
Lead mg/m3 0.24 0.014 0.00053All reference conditions: 273°K, 101.3kPa, 11% O2, dry; Small ≤ 200 lbs/hr, medium > 200 to 500 lbs/hr, and large > 500 lbs/hr.For half hour averages, at least 97% of concentrations must meet the first value and 100% must meet the second value.
RESOURCES Guidelines on best available techniques and
provisional guidance on best environmental practices, to be posted on the Stockholm Convention website
http://www.pops.int/
Reference document on the best available techniques for waste incineration: BAT reference document (BREF), European Commission, 2008; available in the European IPCC Bureau website eippcb.jrc.es/pages/FActivities.htm
o “Standards of Performance for New Stationary Sources and Emissions Guidelines for Existing Sources: Hospital/Medical/Infectious Waste Incinerators – Final rule amendments,” 40 CFR Part 60, US Environmental Protection Agency, 2011
GENERIC TECHNOLOGIES
ChemicalAlkaline hydrolysisChemical disinfectionOthers
GENERIC TECHNOLOGIES
Alkaline hydrolysis
Specifically designed for pathological waste (anatomical waste, organs, tissues, cadavers, contaminated animal carcasses)
Alkali + heat
Two types:
High pressure
Low pressure
Range of capacities:
15 to 4500 kg per cycle
GENERIC TECHNOLOGIES
Chemical disinfectant treatment
Examples of disinfectants used:
Sodium hypochlorite, chlorine dioxide, peracetic acid, lime slurry, quarternary ammonium salts, glutraldehyde
Range of capacities:
40 kg/hr to 700 kg/hr High Speed Hamermill
Pressurized Kill Tank
Sodium Hypochlorite Injection System
Auger System
LFB 12-5
GENERIC TECHNOLOGIES
Biological Treatment for organic wastes (this has been used for placenta and small tissues)
Composting
Vermiculture
Biodigestion
GENERIC TECHNOLOGIES
Others (emerging technologies)
Ozonation
Dry chemical (calcium oxide-based)
Promession for anatomical waste
GENERIC TECHNOLOGIES: COMPARISON OF ENVIRONMENTAL AND OCCUPATIONAL SAFETY
Technology
Environmental Concerns Occupational Safety Concerns
Air Water Solid Residue Notes
Autoclaves X XX X XX High pressure
Hybrid autoclaves X XX X XX High pressure
Continuous steam treatment systems X X X X
Batch microwave technologies X X X X
Continuous microwave technologies X X X X
Frictional heat treatment systems X X X X
Dry heat treatment systems X X X X
Incinerators XXX XX XXX XXX Air emissions, ash
Alkaline hydrolysis technologies X XXX X XX High pressure, alkali
Chemical treatment systems XX XX X XXX Chemical exposure
X – minimal concerns, XX - some concerns, XXX - significant concerns
GENERIC TECHNOLOGIES: COMPARISON OF SOCIAL/CULTURAL ASPECTS
√ - small potential, √√ - medium potential; X – minimal concerns, XX - some concerns, XXX - significant concerns
Technology Potential for Job Creation
Social Concerns Notes
Autoclaves √√ X
Hybrid autoclaves √√ X
Continuous steam treatment systems √√ X
Batch microwave technologies √ X
Continuous microwave technologies √√ X
Frictional heat treatment systems √√ X
Dry heat treatment systems √ X
Incinerators √√ X X X There may be community opposition to incinerators in neighborhoods.
Alkaline hydrolysis technologies √√ X X X It may not be culturally or religiously acceptable for treating body parts.
Chemical treatment systems √ X X The community may be concerned with chemical accidents and releases
GENERIC TECHNOLOGIES: COMPARISON OF INSTITUTIONAL/REGULATORY REQUIREMENTS
X – few basic requirements, X X - some requirements, X X X - many requirements; (1) maintenance and repair of moving parts; (2) maintenance and repair of parts exposed to high temperatures and thermal stresses (e.g., refractories), corrosive gases, fly ash and dust, as well as maintenance and
repair of moving parts especially in the flue gas cleaning system
TechnologyInstitutional Requirements Regulatory Requirements
Notes Notes
Autoclaves X X
Hybrid autoclaves X X (1) X
Continuous steam treatment systems X X (1) X
Batch microwave technologies X X
Continuous microwave technologies X X (1) X
Frictional heat treatment systems X X (1) X
Dry heat treatment systems X X
Incinerators X X X (2) X X XAir emission testing and hazardous ash
disposal
Alkaline hydrolysis technologies X X (1) X
Chemical treatment systems X X (1) X X Chemical storage, disposal and residues
GENERIC TECHNOLOGIES: COMPARISON OF CAPITAL COSTS
Autoclaves
Autoclaves with Shredders
GENERIC TECHNOLOGIES: COMPARISON OF CAPITAL COSTS
Hybrid Autoclaves
GENERIC TECHNOLOGIES: COMPARISON OF CAPITAL COSTS
Batch Microwave Units
Continuous Microwave Systems
GENERIC TECHNOLOGIES: COMPARISON OF CAPITAL COSTS
Incinerators with Air Pollution Control
GENERIC TECHNOLOGIES: COMPARISON OF CAPITAL COSTS
Low-Pressure Alkaline Digesters
High-Pressure Alkaline Digesters
GENERIC TECHNOLOGIES: COMPARISON OF OPERATING COSTS
Technology Range of Capacities(kg/hr)
Range of Operating Costs(USD/kg)
Autoclave 2 to 3600 0.14 to 0.33
Hybrid autoclave 18 to 2200 0.05 to 0.12
Continuous steam treatment 100 to 1800 about 0.15
Batch microwave unit 1.5 to 31 about 0.13
Continuous microwave unit 100 to 810 0.07 to 0.11
Frictional heating 10 to 1500 >0.13
Incinerator with air pollution control 5 to 3500 0.27 to 1.66
Alkaline hydrolysis 7 to 4500 kg per cycle 0.10 – 0.19
Chemical treatment 23 to 410 0.12 to 0.52
GENERIC TECHNOLOGIES: QUALITATIVE COMPARISONS
1 2 3 4 5 6 7 8 9 10
Wide range of capacities +++ ++ ++ + ++ + - ++ + ++
Wide range of waste treated + ++ ++ + ++ ++ - +++ - +
Efficacy of microbial inactivation ++ ++ + + + ++ + +++ +++ ++
Volume reduction + ++ ++ + ++ ++ ++ +++ +++ ++
Mass reduction - + + - - + + ++ +++ -
Minimum space needed for installation ++ + + +++ + + +++ - + +
Minimum installation requirements ++ + + +++ + + +++ - + +
Degree of automation + ++ ++ +++ ++ ++ +++ ++ ++ ++
1 – Autoclaves; 2 - Hybrid autoclaves; 3 - Continuous steam treatment systems; 4 - Batch microwave technologies; 5 - Continuous microwave technologies; 6 - Frictional heat treatment systems; 7 - Dry heat treatment systems, 8 – Incinerators; 9 - Alkaline hydrolysis technologies; 10 - Chemical treatment systems
GENERIC TECHNOLOGIES: QUALITATIVE COMPARISONS
1 – Autoclaves; 2 - Hybrid autoclaves; 3 - Continuous steam treatment systems; 4 - Batch microwave technologies; 5 - Continuous microwave technologies; 6 - Frictional heat treatment systems; 7 - Dry heat treatment systems, 8 – Incinerators; 9 - Alkaline hydrolysis technologies; 10 - Chemical treatment systems
1 2 3 4 5 6 7 8 9 10
Environment + + ++ ++ ++ ++ ++ -- - -
Occupational safety - - ++ ++ ++ ++ ++ -- - --
Job creation (based on equipment size) +++ +++ +++ + +++ ++ + +++ ++ ++
Social acceptance + + + + + + + -- - -
Institutional requirements +++ ++ ++ +++ ++ ++ +++ + ++ ++
Regulatory requirements +++ +++ +++ +++ +++ +++ +++ + +++ ++
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