GENERIC TREATMENT
TECHNOLOGIES FOR
HEALTHCARE WASTE
Jorge Emmanuel
International Experts’ Workshop
UNEP-DTIE-IETC
July 19-20, 2012
Osaka, Japan
TYPES OF TREATMENT TECHNOLOGIES
(BY DISINFECTION PROCESS)
 Thermal
 Temperature
 Chemical
 Concentration
 Irradiative
 Radiation
 Biological
dose
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 Description
 Diagram or sketch
 Types of Waste Treated
 Range of Capacities
 Pathogen Destruction
 Emissions and By-Products
 Operational Details
 Installation Requirements
 Maintenance Requirements

GENERIC TECHNOLOGIES
 Thermal








Autoclaves
Hybrid autoclaves
Continuous steam treatment systems
Batch microwave
Continuous microwave
Frictional heating
Dry heat
Incineration and related technologies
GENERIC TECHNOLOGIES
 Autoclaves
based on design
Jacketed
 Retort
Pressure Gauge

Release
Valve
Air
Safety
Valve
Vacuum
Filter
Jacket
Vacuum
 Non-vacuum

Autoclave Chamber
Charging
Door
Steam
Trap
Thermocouple
Steam
Trap
Drain
Steam
GENERIC TECHNOLOGIES
Autoclaves
 Range 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
 Gravity
autoclaves
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
Autoclaves

Better steam penetration, shorter
exposure time

Higher maintenance requirements
than autoclaves

Higher costs than autoclaves

Range 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

Range of capacities:


Steam Treatment Systems
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

Range of capacities:


Microwave Unit
30 to 210 kg/hr
controls
microwave
generator
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
waste
bin
GENERIC TECHNOLOGIES
 Continuous
Microwave Unit
lid
automatic
loader
hopper
air treatment system used when the
lid is opened
microwave
generators
shredder
waste
bin
holding
tank
outlet
GENERIC TECHNOLOGIES
 Continuous

Range of capacities:


Microwave Unit
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 TECHNOLOGIES
 Frictional

Range of capacities:


10 to 500 kg/hr
Types of waste treated:


Heating Systems
Same as hybrid autoclaves and continuous steam
or microwave treatment systems
Typical cycle
100
T ºC
time
GENERIC TECHNOLOGIES
 Frictional
Heating Systems
Vapor
exhaust to
air filters
Electrical
panel
Lid
Sterilization
chamber
with high
speed rotor
blades
Discharge
bin
GENERIC TECHNOLOGIES
 Dry
Heat Systems

Mainly natural or forced
convection (hot air) and
conduction from electrical
resistance heaters

Range of capacities:


Types of waste treated:


0.2 to 10 kg/hr
Same as autoclaves
Intended for small facilities
GENERIC TECHNOLOGIES
 Incineration

Range of capacities:


Types of waste treated:


10 kg/hr to over 20 tonnes per day
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
To Stack
Secondary Combustion Chamber
Air Pollution Control System
Secondary Burner
Ram Feed
Primary Combustion Chamber
Primary Burners
Ash Sump
GENERIC TECHNOLOGIES

Multi-chamber excess air incinerator
GENERIC TECHNOLOGIES

Rotary kiln
Stack
Ram or Auger
Feeder
Packed
TowerDemister
Secondary
Combustion
Chamber
Dry
Chemical
Gas
Scrubber
Hopper
Baghouse
Fabric
Filter
ID
Fan
Venturi
Quench
Rotary Kiln
Ash Sump
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 REQUIREMENTS UNDER THE
STOCKHOLM CONVENTION

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
EXAMPLES OF OTHER ENVIRONMENTAL
REQUIREMENTS
Pollutant
Units
US EPA emission limits
EU emission limits
Small
Medium
Large
Daily
average
0.5-hour
average
Particulates
mg/m3
50
17
14
10
10, 30
CO
mg/m3
18
1.6
9.8
50
100, 100
0.0099
0.011
0.027
Dioxins/furans ng TEQ /m3
0.5-8 hour
average
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
Lead
mg/m3
0.24
0.014
0.00053
0.05
All 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


o
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
“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
 Chemical
Alkaline hydrolysis
 Chemical disinfection
 Others

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

Examples of disinfectants used:


disinfectant treatment
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
P ressurized K ill Tank
LFB 12
-5
A uger System
S odium Hypochlorite Injection System
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
Environmental Concerns
Technology
Occupational Safety Concerns
Air
Water
Solid Residue
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
XXX
XX
XXX
XXX
Air emissions, ash
X
XXX
X
XX
High pressure, alkali
XX
XX
X
XXX
Chemical exposure
Incinerators
Alkaline hydrolysis technologies
Chemical treatment systems
Notes
X – minimal concerns, XX - some concerns, XXX - significant concerns
GENERIC TECHNOLOGIES:
COMPARISON OF SOCIAL/CULTURAL ASPECTS
Potential for
Job Creation
Social
Concerns
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
√√
XXX
There may be community opposition to
incinerators in neighborhoods.
Alkaline hydrolysis technologies
√√
XXX
It may not be culturally or religiously
acceptable for treating body parts.
Chemical treatment systems
√
XX
The community may be concerned with
chemical accidents and releases
Technology
Notes
√ - small potential, √√ - medium potential; X – minimal concerns, XX - some concerns, XXX - significant concerns
GENERIC TECHNOLOGIES:
COMPARISON OF INSTITUTIONAL/REGULATORY
REQUIREMENTS
Institutional Requirements
Regulatory Requirements
Technology
Notes
Autoclaves
X
Notes
X
Hybrid autoclaves
XX
(1)
X
Continuous steam treatment
systems
XX
(1)
X
Batch microwave technologies
X
X
Continuous microwave
technologies
XX
(1)
X
Frictional heat treatment systems
XX
(1)
X
Dry heat treatment systems
Incinerators
X
X
XXX
(2)
XXX
Alkaline hydrolysis technologies
XX
(1)
X
Chemical treatment systems
XX
(1)
XX
Air emission testing
and hazardous ash
disposal
Chemical storage,
disposal and residues
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
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
Range of Capacities
(kg/hr)
Range of Operating Costs
(USD/kg)
2 to 3600
0.14 to 0.33
18 to 2200
0.05 to 0.12
100 to 1800
about 0.15
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
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
Technology
Autoclave
Hybrid autoclave
Continuous steam treatment
Batch microwave unit
Incinerator with air pollution control
GENERIC TECHNOLOGIES:
QUALITATIVE COMPARISONS
1
2
3
4
5
6
7
8
9
10
+++
++
++
+
++
+
-
++
+
++
Wide range of waste treated
+
++
++
+
++
++
-
+++
-
+
Efficacy of microbial inactivation
++
++
+
+
+
++
+
+++
+++
++
Volume reduction
+
++
++
+
++
++
++
+++
+++
++
Mass reduction
-
+
+
-
-
+
+
++
+++
-
Minimum space needed for installation
++
+
+
+++
+
+
+++
-
+
+
Minimum installation requirements
++
+
+
+++
+
+
+++
-
+
+
Degree of automation
+
++
++
+++
++
++
+++
++
++
++
Wide range of capacities
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
2
3
4
5
6
7
8
9
10
Environment
+
+
++
++
++
++
++
--
-
-
Occupational safety
-
-
++
++
++
++
++
--
-
--
+++
+++
+++
+
+++
++
+
+++
++
++
+
+
+
+
+
+
+
--
-
-
Institutional requirements
+++
++
++
+++
++
++
+++
+
++
++
Regulatory requirements
+++
+++
+++
+++
+++
+++
+++
+
+++
++
Job creation (based on equipment size)
Social acceptance
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
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