Incinerators:

	Incineration is a process where the combustible waste is reduced to exhaust gaseous products and the incombustible waste is reduced to ash. The nature of gaseous emissions and ash from an incinerator depend upon the type of waste being incinerated and incineration conditions. Incineration is effective when the waste is combustible.
An incinerator carries out complete combustion of carbon-containing compounds. Complete combustion takes place in the presence of fuel and air. The fuel provides heat energy to attain incineration temperature and air provides oxygen for combustion. In some cases, the waste itself provides heat energy. Historically, incineration has been the most common method used by health care facilities

Salient Features

1. Depending upon the contents of the waste, the emissions from incinerator could be toxic and
     hence incinerator requires extensive air pollution control equipment.
     Several types of air pollution control equipment are available to reduce particulate and other
     gaseous emissions. Some of the commonly used air pollution control devices include venturi
     scrubbers, packed towers, bag filters, multi-cyclones etc.
2. The key parameter in an incinerator is the combustion chamber temperature. Current criteria
     require that biomedical waste incinerators be operated at a minimum temperature of 1200°C and
     that the waste be exposed for at least two seconds.
3. The standards for operation are cited in the Bio-Medical Waste (Management and Handling) rules,
     2000. Emission control equipment is required to ensure that the air discharges meet the applicable
     regulatory requirements.
4. If the requisite temperature is not ensured, incomplete combustion can result in organic
     compounds such as dioxins and furans being emitted, which are much more detrimental than the
     starting material.
5. Also, ash from the incinerators is categorized as hazardous waste and requires disposal in a
     secured landfill.
6. Incinerator reduce the volume and weight by more than 95% thereby reducing the transportation
     and land disposal costs. Technology is indigenously available and service facilities are available in
     the country.
7. They are available in different sizes to match the quantity of waste.
8. A capacity of less than 50 kg/hour is not recommended.
9. The capital cost of the incineration set-up increases due to addition of air pollution control
     equipment. It is mandatory to install suitable control equipment to meet regulatory requirements.
10. However, for larger volumes of waste, the cost will become favourable. Incinerator consume lot of
     fuel and hence their operational cost is high. In view of the fuel costs, plant personnel will be
     tempted to charge the incinerator even before the required temperatures are attained. This will
     lead to incomplete combustion and associated air pollution problems.
11. If the waste is not properly segregated and if PVC material is allowed to enter the waste stream,
     the air emissions from the incinerator are likely to contain toxic compounds – polychlorinated
     dibenzo-p-dioxins (referred to as dioxins) and polychlorinated dibenzo furans (referred to as furans).
12. Stack gas emissions may contain potential toxic pollutants such as HCl, cadmium, mercury and
      lead. The presence of glass in the waste stream could also cause problems (such as slagging)
      when the waste is incinerated.
13. Efficiency depends on process optimization; hence it requires skilled operators. Air pollution
      control equipment lead to liquid waste, which may require certain treatment prior to discharge.
14. The public and NGOs are opposing incineration of infectious medical waste (both in India and in
      developed countries) in view of toxic air emissions and ultimate disposal of ash.
15. The project risk is high in view of strong opposition to incinerators at the national and international
      levels. Environmental clearance and public participation are required before siting a facility.
16. A proper operational procedure and emergency planning is required in view of occupational
      hazards and potential fire accidents.

Advantages

1. An incineration system is preferred and widely recommended for certain categories of waste such
as anatomical and pathological waste, discarded materials (swabs, bandages, cotton, dressings)
contaminated with blood and body fluids, discarded medicines
2. Incinerator is appropriate for pathological waste, anatomical and non-anatomical biomedical waste.
3. Energy recovery is possible
4. Segregation of waste is vital to the sustainable operation of an incinerator.
5. Significant volume reduction is a key factor for incinerator
6. Incinerator provides assured destruction
7. Sterilization is also possible with incinerator
8. Incinerator has ability to manage most type of waste with little processing before treatment incinerator however is a necessary technology for above mention categories like tissu and body parts, old expiry date drugs, hazardous chemicals, cytotoxic waste etc.

Components of an Incinerator