SOLID WASTE MANAGEMENT

Shree K.K. Shashtri Gov. Sci. CollegeEnvironmental Science

Solid Waste Management

Definition of Solid waste management

It comprises of purposeful and systematic control of the generation, storage, collection, transport, separation, processing, recycling, recovery and disposal of solid waste.

IntroductionIndia’s population is 1.22 billion and the urban

population is 38 billion (as per 2011 Census).

The growth rate of population for India in the last decade was 17.64%.

The growth rate of population in rural and urban areas was 12.18% and 31.80% respectively.

The solid waste generated in Indian cities has increased from 6 million tones in 1947 to 48 million tones in 1997 and is expected to increase to 300 million tones per annum by 2047 (CPCB, 2000).

Quantity of Solid Waste

Per capita generation of waste varies from 200 gm to 600 gm per capita/day. Average generation rate at 0.4 kg/capita/day in 0.1 million plus towns with collection efficiency of 50-90% of the total solid waste generated.

In India per capita waste generation is increasing by 1.3% per year with urban population increasing by 3.5% per year. Results in yearly around 5% increase of waste generation.

In USA it is 2 kg/person /day (approx.760kg/capita/year) excluding hazardous waste.

Japan and European countries generate less than half of the waste generated by USA.

Composition of solid waste

Composition varies with The socio economic status ( Lifestyle, consumption

pattern)Geographical LocationSeasonCollection FrequencyPopulation diversityPublic attitudeLegislation

Characteristics of Municipal Solid Waste

These percentages vary from city to city depending on food habits

Type of Waste Quantity

Compostable / Bio-degradable matter

30% - 55% (can be converted into manure)

Inert material 40% - 45% (to go to landfill)

Recyclable materials 5% - 10% (Recycling)

Composition of urban solid waste

Type of Waste Quantity

Organics 40-50%

Paper 3-5%

Ash & Dust 15-30%

Textile 3-7%

Plastic 1-10%

Glass 1%

Metal 1%

Other 7-10%

Waste cannot be removed as fast as it is produced, it must be sorted and transported at specific frequencies.

The removal of waste from individual houses is termed as collection of waste.

Collection is carried out in five phases1. House to can2. Can to truck3. Truck from house to house4. Truck routing5. Truck to disposal

Collection components

1. Collection points – They depend upon the locality (residential, commercial, industrial)

2. Collection Frequency- It depends on requirements of locality, climatic condition, quality of waste container.

Composition of wasteSeason -Hot and wet climate – twice a weekLocality - Residential – frequentQuality – Closed container – 3 daysOpen container- daily collection

Collection components

3. Storage Containers- Efficient collection system requires careful consideration of type, size and location of containers.

Family – Small containers (manual handling)Residential units – large – Mechanical handling

Types of containers

1. Stationary containers – Used for contents to be transferred to collection vehicles at the site of storage.

2. Household Storage- Plastic or metal bucket of 5-6 lit capacity with lid.

3. Litter bins- provided to enable the citizens to deposit their behavioral waste while moving along the streets and public places. (30- 50 lit. capacity) Placed near bus stops, parks. Made up of fire resistant material and covered to prevent entry of rain water.

Types of containers4. Communal container– Compactor collection

container. Fixed/moving. Movable containers are with accessories provided for lifting mechanism of collection vehicles.

Vehicle can lift and empty mechanically. Capacity is generally 1-4 m3.

At vegetable markets & large commercial centers, capacity is 15- 20 m3 and consist of wheels.

Collection vehicle keep empty container before it hauls the filled container.

Ideally these should be located 100 -200 m apart for economic reasons. Fuel consumption increases if vehicle has to stop at every 50m.

Types of containers

5. Hauled container- Used for contents to be directly transferred to a processing plant, transfer stations / disposal sites for emptying.

When mechanical collection system is used the containers are specifically designed to fit the truck mounted loading mechanisms.

For public health and safety it must be securely covered.

Convenience– must be manageable by residents and collection crew.

Collection VehiclesIt must be appropriate to the terrain, type, density of

waste generation points.It also depends on the strength, capability of crew that

work with it.

1. Small scale collection/ muscle powered vehicles– For densely populated areas with narrow lanes.

Area with relatively less volume of waste generated.small carts, rickshaws pulled by people or animal.

2. Bell ringing systemCollection vehicle is provided with a bell.Residents from adjoining areas come to the vehicle to

deposit the waste.Efficiency of the system depends upon co operation of

citizens.

Collection Vehicles3. Non Compactor truck- Used in small cities when

waste tend to be dense and have little potential for compaction.

Suitable if the distance between collection site and disposal is less than 15km.

Capacity is 10-12 m3

Covering of waste is required.Used when labor cost is high.

Three wheeler garbage vehicle

Non Compactor truck

Collection Vehicles4. Compactor truckSince the waste is compacted hydraulically the weight

of solid waste per trip is 2-2.5 times larger.Allows the waste containers to be emptied into vehicles

from rear.Capacity is 12-15 m3.Inhibits vectors from reaching the waste during

collection and transport.

Refuse compactor

Collection Vehicles

Transfer Station

A transfer station is an intermediate station between final disposal and collection point to increase the efficiency of the system.

It helps the collection vehicles and crew to remain closer to routes.

It is the best option if the disposal site is far from collection area.

It is a centralized facility, waste is unloaded from smaller collection vehicles and transferred to large vehicles for transport to disposal site.

Transfer StationIn some cases transfer station serves as a preprocessing

point where waste are dewatered, compressed.

A centralized sorting, recovery of recyclable material is also carried out.

It helps in decreasing the cost of travelling from collection to disposal site as the collection vehicle size increases.

Selection of transfer station depends on types of waste received, types of collection vehicles and site topography and access.

Transfer Station

Advantages of transfer stationLower collection cost Reduced fuel and maintenance cost for collection

vehicle.Opportunity to recovery and recycle at station.

Disadvantage of transfer stationif waste is not handled properly, attract flies, odor,

traffic and noise.

Types of Transfer Station

Depending upon size1. Small / medium transfer station– capacity less than

100 tons/day2. Medium transfer station- capacity range from 100-

500 tons/day.3. Large transfer stations– For heavy commercial use by

private and municipal collection vehicle.

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