Treatment systems

Autoclave

Hydroclave

Microwave

Incineration

Chemical

Description

Steam sterilization (Direct heating)

Steam sterilization, (indirect heating) simultaneous shredding and dehydration

Microwave heating of pre-shredded waste

High temperature waste incineration

Mixing pre-ground waste with chemicals, such as chlorine

Sterilization efficacy

Medium

Medium

Medium

High (total destruction of micro-organisms)

Dependent on chlorine strength and dispersement through the waste

Capital cost

Low

Low

High

High

Moderate

Operating cost

Low

Low

High

High

Low

Operator maintenance skills

Low skill level required

Low skill level required

Automated, but highly complex and high level maintenance skill required

High level operator and maintenance skills required

High level required for chemical control and grinder

Air emissions

Odorous but non-toxic

Somewhat odorous but non-toxic

Somewhat odorous but non-toxic

Can be highly toxic

Some chlorine emissions

Water emissions

Odorous, may contain live micro-organisms

Odorous but sterile

Negligible

None

None

Treated waste characteristics

Wet waste, all material recognizable

Dehydrated, shredded waste, unrecognizable material

Shredded but wet waste

Mostly ash, may contain toxic substances

Shredded wet waste, containing chemicals used as disinfectants