Solid Waste #1

Solid Waste

Solid waste is the unwanted or useless solid materials generated from human activities in residential, industrial, or commercial areas.

Sources and Types of Solid Waste:

Solid waste can be classified into different types depending on their source:
1. Municipal Waste
2. Industrial Waste
3. Hazardous Waste

1.    Municipal Waste

1. Solid wastes generated from different zones of the city differ in characteristics. Their solid wastes comprise refuse, ordinary refuse (includes garbage and Rubbish), and trash.
2. Refuse refers to non-hazardous solid waste from the community requiring collection and transporting to a disposal site.
3. Garbage comprises items that are highly decomposable food, waste vegetables, and meat scraps.
4. Rubbish contains mostly dry, non-decomposable material like glass, rubber, tin cans, also combustible material like paper, textiles, wooden articles, etc.
5. Hence, Community refuse can be referred to as Municipal Solid Waste (MSW).

2. Industrial Waste

1. Industrial wastes are generated from industrial activities or manufacturing processes.
2. All three types of wastes, solid, liquid, and gaseous are generated.
3. Industrial waste can be categorized as non-hazardous. It is well known that hazardous wastes have the potential for a very deleterious impact on the environment and life in general.

3. Hazardous Waste

1. A hazardous substance can be defined as anything which because of its quantity, concentration or characteristics may contribute to increased mortality, illness, or hazard to human health and environment if not properly stored and transported or disposed of.
2. As per the Resource Conversion and Recovery Act (RCRA), the USA the hazardous waste is one that possesses any one of the four characteristics, such as Ignitability, Corrosivity, Reactivity, Toxicity.
3. These are highly infectious and radioactive.

Effects of Solid Waste

A.  Public Health Effect

• Disease vectors & Pathways
  • Waste dump provides food to vermin & agents of various diseases.
  • Pathogens transmit via insects, flies, mosquitoes, roaches, animals like pigs, rodents, etc.
• Flies:
  • Mostly housefly transmit Typhoid, GI and dysentery. They have flight range of 10km, and spread to wide area.
  • To avoid flies, the frequency of waste collection is adequate.
  • Also, the containers used for storage is to restrict access to files.
  • Covering solid waste with a layer of earth at landfill sites at the end of the day, arrests the problem of fly breeding at the final stage.
• Mosquitoes:
  • Transmit malaria, filarial & dengue fevers.
  • Since they breed in stagnant water, control measures should take on the elimination of breeding places such as tins, tires, cans, etc.
• Roaches:
  • Cause infection by physical contact and transmit Typhoid, Cholera, and Amoebiasis.
• Rodents (rats):
  • Spread plague, leptospirosis, rat-bite fever.
• Occupational Hazard:
  • Workers handling wastes face risk of accidents, due to lack of safety like injuries.
  • So, they must wear gloves, masks & be vaccinated.

• The Diseases include:
  • Skin & blood infections due to glass, metals.
  • Eye and respiratory infections resulting from exposure to infected dust.
  • A disease that results from bites of animal feeding on the wastes.
  • Intestinal infections by microbes on wastes.
  • Bone and Muscle disorder resulting from handling heavy containers and loading vehicles.

B.  Environmental Effects

• Air Pollution:
  • Burning of solid waste in open dumps or in improperly designed incinerators emit pollutants to the atmosphere.
  • Emission includes particulate matters SO2, NO2, HCl, CO & CO2, Hg, etc.
  • Discharge of Arsenic, Cadmium, and selenium is to be controlled since they are toxic at relatively low levels. 
• Water and Land Pollution:
  • Results from dumping in open areas and stormwater drains, improper design and construction of landfills.
  • Control of the infiltration rate from rainfall and surface runoff is essential to minimize leachate.
  • Due to the flow of groundwater via Solid Waste at the landfill, percolation of rainwater causes groundwater contamination.
• Visual Pollution:
  • The aesthetic view is affected by piles of wastes on the roadside.
• Noise Pollution:
  • Noise Pollution due to operation at sorting, incineration, transferring, landfills due to the operation of large machines, vehicle movements, etc.
• Odour Pollution:
  • Obnoxious odor due to the presence of decaying organic matter of open dumps.
• Explosion Hazards:
  • Landfill gas released by anaerobic decomposition contains Methane (35-70%) prevented by venting, flaring by use of barriers.