CH: Solid waste Management
v Type of Solid Waste:
1.
Municipal
Waste:
➤The municipal wastes includes garbage, rubbish, demolition debris, dead animals, street sweeping, constructions wastes and plant treatment wastes.
➤ The sources of these wastes are domestic work,
restaurants, public places, markets and institutions.
2.
Industrial
Waste:
Ø The industrials waste includes fly ash, toxic
materials, paints, chemicals
Ø These wastes are produced from industrial
activities.
3.
Agricultural
wastes:
➤ These includes wastes from jute, cotton, tea,
coffee, coconut and sugarcane plantations, straw and cattle waste
➤ These are residues from agricultural farms and
fields.
4.
Commercial
Wastes:
5.
Hazardous
Wastes:
➤ The hazardous wastes include radioactive,
chemical, biological and flammable wastes and explosives.
➤ The sources of these wastes are hospitals, nuclear plants, industries, research institutes and laboratories.
Garbage:
➤ It is domestic solid wastes containing food
wastes.
➤ The food wastes include meat fruit, and vegetable residues
Rubbish:
➤It include both combustible and non-combustible solid wastes except food waste.
➤Combustible rubbish is composed of papers, cardboards, textiles, wood, rubber, leather, and plastic materials.
➤Non-combustible rubbish includes crockery, metals, aluminium cans, tin cans and broken glass.
Disposal of Refuse:
1.
Open
Dumping:
➤Oldest method of disposing SW
➤SW collecting from the city zone is dumped in low laying areas located far off from the city
➤Not an eco-friendly method and thus results in contamination of environment
➤. This method is highly unacceptable at it gives unsightly nuisances, obnoxious smell and is a breeding place for flies and mosquitoes.
2.
Sanitary
land filling:
➤Dumped into the low laying layer and covered with good earth layer
➤Get stabilized, generally within 2 to 4 months.
➤About 90% Indian refuse is disposed of in this manner
➤Leachate in sanitary land filling: During rainy season, when excess water seeping through the area, may come out of the dump, as a coloured liquid, called leachate. This is highly poisonous and polluted.
➤Gas production:
3.
Incineration
and thermal Pyrolysis:
Incineration:
➤This method is widely used in countries like
USA where the calorific value of refuse is high.
➤It consists of burning of refuse at high
temperatures in furnace called incinerator. Large sized incinerators are called
destructors.
➤The temperature of combustion chamber should be more than 650oC.
➤Large scale of air pollution particularly due to emission of Dioxins remains a serious problem with the incinerators.
Pyrolysis
➤Most
organic compound can be converted into gaseous, liquid and solid fraction
through a combination of thermal cracking and condensation reactions in absence
of Oxygen. This process is known as Pyrolysis
➤This
process is also known as Destructive distillation.
➤It is an endothermic process- requiring continuous input of heat energy
➤Best suitable of Disposal for Plastic and Rubber wastes
4.
Disposal
refuse by Pulverization:
➤Refused by pulverized in grinding machine
5. Composting:
➤Composting of refuse is a biological method of decomposing solid wastes.
➤In India, the composting is practiced in rural
area on the mixture of soil and refuse
➤There are two methods are adopted
I.
Indore
Process:
Ø It uses manual turning of piled up mass (refuse
+ night soil), for its decomposition under aerobic conditions.
II.
Bangalore
Method:
➤ It is primarily anaerobic in nature
➤ Widely adopted by municipal authorities
throughout the country
➤ After 4 to 5 months the refuse gets fully stabilized and changes into a brown coloured odourless innocuous powdery mass is called humus.
Eutrophication: Eutrophication results from the enrichment of a body of water with fertilizing elements when in the presence of sunlight stimulate the growth of algae and other aquatic plants.
