Air Pollution Technology and Medical Waste


Pollutants

  • Sulfur dioxide - produced in combustion
  • Carbon monoxide - produced in inefficient combustion
  • Aldehydes - produced in decomposition of animal bodies (fats, oils)
  • Nitrogen oxides - produced in combustion
  • Phosgene - produced in decomposition of chlorinated hydrocarbons
  • Suspended particulates - many types of operations produce solid and/or liquid particles that become suspended in air and are referred to as “particulates”. They range up to 1 millimeter in diameter.
  • Odor - produced by many sources

Methods of Dealing with Air Pollutants

Electrostatic precipitators

Upsides

  • Can be extremely efficient, especially is processing a steady waste stream
  • Can remove very small particulates
  • Low pressure drop through unit
  • Can operate at high pressure and/or high temperature

Downsides

  • High cost - capital cost
  • Ozone produced in operation
  • Removes particulate but not dissolved gases
  • High voltages can be hazards for personnel
  • Big floorplan
  • Cannot handle input streams that vary in composition and flowrate without loss of efficiency
  • Unsuitable for some waste streams (e.g. contain combustibles)

Condensers

Upsides

  • Can recover condensed material that might be useful
  • No need to add material to waste stream

Downsides

  • Hard to get pollutants down to very low levels just by condensing
  • Coolant system cost (capital and operating) and complexity

Combustion

Upsides

  • Simple, can destroy a lot of chemical compounds
  • Really efficient destruction of organic contaminants if operated correctly
  • Generation of heat which can be useful.

Downsides

  • High operating costs - fuel, personnel
  • Hazards of playing with fire
  • Potential for incomplete combustion and production of carbon monoxide and other hazardous chemicals such as dioxins