2. Waste- Definition & Classification
Any material which is not needed by the
owner, producer or processor.
Classification
• Domestic waste
• Factory waste
• Waste from oil factory
• E-waste
• Construction waste
• Agricultural waste
• Food processing waste
• Bio-medical waste
• Nuclear waste
4. Classification of Wastes
• Solid waste- vegetable waste, kitchen waste, household
waste etc.
• E-waste- discarded electronic devices like computer, TV,
music systems etc.
• Liquid waste- water used for different industries e.g.
tanneries, distilleries, thermal power plants
• Plastic waste- plastic bags, bottles, buckets etc.
• Metal waste- unused metal sheet, metal scraps etc.
• Nuclear waste- unused materials from nuclear power plants
5. SOURCES OF SOLID WASTE
The solid waste (i.e. garbage) includes
the dry refuse like street sweepings, ash,
mud, decayed vegetables and fruits,
grass, leaves, paper pieces, cloth pieces,
etc. The following are the sources of such
solid waste:
6. (a) Market
(b) Road Side Dustbins
(c) Residential Area
(d) Street Sweepings
(e) Cinema and Theatre Halls
(f) Schools and Colleges
(g) Hospitals
7. COLLECTION AND REMOVAL OF
SOLID WASTE
The following vehicles are employed for the
removal of solid waste.
1. Rickshaw-vans
6.Wheeled Baskets
7.Trailors
8.Trucks
8. DISPOSAL OF SOLID WASTE
The following are the general methods of disposal:
(a) By trenching: In this method, trenches are
excavated in barren lands far away from the town The
garbage is dumped into the trench and leveled properly.
(b) By land filling: In this method, the garbage is
dumped in low-lying area phase by phase.
(c) By incineration: The process of burning the
garbage into ash is known as incineration
9. (d) By pulverization: The method of grinding the
garbage into powder is known as pulverization
(e) By composting: In this method, the garbage is
converted to manure in a mechanical compost plant. This is
a hygienic method of garbage disposal. Here, the worthless
materials may be obtained as useful materials like fertilizer
(f) By disposal to sea: In coastal towns, the
disposal of garbage into the sea But the garbage should be
discharged into the deep sea by studying the current and
wave action of the sea so that it may not return to the shore
again.
10. Solid Waste in Pakistan
• 7.2 million tonnes of hazardous waste
• One Sq km of additional landfill area every-year
• Rs 1600 crore for treatment & disposal of these wastes
• In addition to this industries discharge about 150 million
tonnes of high volume low hazard waste every year,
which is mostly dumped on open low lying land areas.
11. Growth of Solid Waste In Pakistan
• Waste is growing by leaps & bounds
• In Pakistan , population is increasing day by day from 16
caror to 18 caror.
• During the same period, municipal solid waste has grown
from 3200 tonnes to 5355 tonne, an increase of 67%
• Waste collection is very low for all Pakistan cities
• Cities like Karachi, Lahore produces 2000 tonnes of waste
per annum, the ever increasing waste has put pressure on
hygienic condition of the cities
12. Waste Collection in Pakistan
• Primarily by the city municipality
-No gradation of waste product e.g. bio-degradable,
glasses, poly bags, paper shreds etc
-Dumps these wastes to the city outskirts
• Local Talukas / Distt: (Rag pickers)
-Collecting small iron pieces by magnets
-Collecting glass bottles
-Collecting paper for recycling
13. Hazardous / Toxic Waste & Dumping Site
• Industrialized countries have waste
management problems
• Developed countries have strict
environment regulation norms
• Most attractive option for them- to dump
into developing countries
14. Major Polluting Industries in Pakistan
• Around 2500 tanneries discharge 24
million cu m of waste water containing
high level of dissolved solids and 4,00,000
tonnes of hazardous solid waste
• Thermal power plants discharge huge waste
materials
16. Managing Waste
Recycling: Processing of a waste item into usable forms.
Benefits of recycling:
-Reduce environmental degradation
-Making money out of waste
-Save energy that would have gone into waste handling &
product manufacture
Saving through recycling:
-When Al is resmelted- considerable saving in cost
-Making paper from waste saves 50% energy
-Every tonne of recycled glass saves energy equivalent to
100 liters of oil
17. Recycling not a solution to all problems!
Recycling is not a solution to managing every
kind of waste material
For many items recycling technologies are
unavailable or unsafe
In some cases, cost of recycling is too high.
18. Solution: More Profit With Zero Waste
• Exchanging output that are considered
waste
• Waste of one could be input or raw
material for others
• Evolving a closed system- matter & energy
circulate within
• System was not designed to be so
• The system of exchange evolved in 10
years
19. Problems in Dealing With Solid Waste
• Education & voluntary compliance
• Collection of waste
• Technological interventions
• Institutions & regulatory framework
• Absence of mandatory standards for waste reduction
• Market action for waste reduction
Source: The Energy & Resources Institute