Waste Management Overview

Waste

• Waste is any form of liquid, semi-liquid, solid, or gaseous material produced from natural and anthropogenic sources.
• Waste is also called garbage, trash, junk, debris, and refuse. 

Classifications of Waste

• Typical classifications of solid waste:
  • Refuse: Is all putrescible and non-putrescible waste except body wastes.
  • Garbage: Putrescible wastes from food, slaughterhouses, canning and freezing industries.
  • Rubbish: Non-putrescible wastes either combustible or non-combustible.
    • Combustible wastes: Wood, paper, rubber, leather and garden wastes.
    • Non-combustible wastes: Glass, metal, ceramics, stones and soil.

Healthcare Waste

• Waste from healthcare settings is categorized as:
  • Infectious Waste
  • Non-Infectious Waste

Hazardous Waste

• Hazardous waste includes:
  • Ignitable
  • Reactive
  • Corrosive
  • Toxic

Solid Waste Management (SWM)

• SWM refers to the collection, transport, processing, recycling or disposal of waste materials with the effort to reduce their effect on:
  • Human health
  • Local aesthetics
  • Amenity

Functional Elements of SWM

• Generation to final disposal (cradle to grave)
• Six functional elements of municipal solid waste management:
  • Waste generation
  • Waste handling and sorting, storage, and processing at the source
  • Collection
  • Sorting, processing and transformation
  • Transfer and Transport
  • Disposal

Hierarchy of Waste Management

• Arrangement in order of rank which gives a priority listing of the waste management
• The hierarchy usually adopted is:
  • Waste minimization/reduction at source
  • Recycling
  • Waste processing (with recovery of resources i.e. Materials (products) and energy)
  • Waste transformation (without recovery of resources)
  • Disposal on land (landfilling)

Integrated Waste Management (IWM)

• Selection and application of suitable techniques, technologies, and management programs
• EPA identified four basic management options (strategies) for IWM:
  • Source reduction
  • Recycling and composting
  • Combustion (waste-to-energy facilities)
  • Landfills

Management of Hazardous Healthcare Waste

• Aim: Contain infectious waste and reduce risks to public health
• The steps include:
  • Waste minimization
  • Segregation
  • Recycling, adequate packaging, handling and storage
  • Proper treatment and disposal

Incineration

• Incinerators convert combustible materials into ashes or residues.
• Gases are ventilated through the chimney stack into the outer air.
• Serves the purpose of destroying infectious microorganisms in the waste.
• If there are no incinerators, then open pit burning is also possible.

Chemical or High-Level Disinfection

• Preferred treatment for liquid & solid infectious waste
• Chlorine and glutaraldehyde are the best chemical disinfectants; 0.5% chlorine solution for 10 minutes being the most appropriate.

Encapsulation

• Filling ¾ of a container with waste
• Filling with immobilizing material such as cement mortar, bituminous sand, clay material, plastic foam
• Dispose of the container in a landfill after drying.