various types of solid waste and their disposal and control measures

1. DEVIPRIYA P V
M PHARM
ENVIRONMENT AND HEALTH
SOLID WASTE DISPOSAL AND CONTROL

2. Solid waste disposal and
control
 Waste: unwanted solid and liquid material
from household, streets, commercial
establishments and industries.
 Scavanging: collection and disposal of refuse
which is not carried by the sewers but done by
natural labour.
 Conservancy system: the collection and
disposal of human excreta by manual labour.
 Water carriage system: the removal of
sewage through sewers and drains.
 Refuse : solid waste material/ discarded
waste matter.

3.  The refuse is the discarded material from houses,
streets, commercial, industrial and agricultural
activities.
 Refuse generally contains ash, paper, metal, wood,
glass, rags, dust, peelings of fruits, vegetables & left
over foods etc.
 Refuse from rotton vegetables, fruits, waste food is
called garbage.
 Industrial waste mainly contain burnt fuel, metal
,wood, glass pieces, paper, dust, chemicals &
harmful liquid waste.
 The accumulation of refuse is a health hazard
because it can result in development of diseases,
pollution of water, air and soil.

4. Storage and collection of Refuse
 Household waste should be stored in sanitary
dust bins covered with a lid.
 Street and road side refuse should be stored in
large size public bins.
 Wheel barrow or street refuse cart can be used
for the collection of refuse.
 The collected should be carried in covered
vehicles to the site of disposal site.
 Collection of refuse in paper sacks or polythene
sacks is also becoming popular

5.  Methods used for refuse disposal:
1. Dumping
2. Controlled tipping
3. Burial
4. Composting
5. Burning.

6. Dumping:
 Simplest and easy method of disposing dry refuse.
 Low lying areas from habitation is selected.
 When the area is filled with refuse, it is leveled and
covered with earth.
 But, causes public nuisance as it emits offensive
gases, and it acts as breeding places for files, attract
rodents, pigs, stray cattles etc.
 Also leads to air and ground water pollution.
Controlled tipping:
 Pits of 3 feet depth are dug away from the habitation.
 The refuse is put in the pit and covered with earth
daily.

7.  During this period the refuse gets converted to
manure.
 After the end of 6 months, the pit is dug open and the
manure is taken which can be used in agricultural
fields.
Burial:
 For disposal of dry refuse.
 A pit is dug and refuse is dumped in it & covered with
earth daily.
 When the pit is full it is completely covered with earth
and another one is dug for further use.
Compositing:
 The process of converting the organic matter into
manure with the help of bacterial action.

8.  When the pit is full it is covered with earth and left as
such for 6 months for composting.
 As a result of chemical and bacterial action intense
heat is produced(60°C) which kills the pathogenic
microbes.
 After 4-6 months the decomposition is complete and
the manure formed is used for agricultural purposes.
 The pits are reused
 This method of disposal of refuse and human excreta
is also known as Hot fermentation process.
Mechanical compositing:
 Advanced method of refuse disposal.
 The water insoluble or large sized substances such as
metal, rags, glass, stones etc are sorted from refuse

9.  This refuse is then mixed mechanically with sewage
containing human excreta and incubated.
 The decomposition completes in 4-6 weeks and the
so formed compost is used as manure.
Burning(Incineration):
 Equipment used is incinerator.
 Suitable for disposal of hospital refuse because it
may contain various types of discharges, blood and
dead issues of patients.
 If refuse contain pieces of glass, metal ,sand etc it
must be sorted out before burning.
Drawbacks of burning:
 Expensive, direct loss of manure, an incinerator is
required, not effective in rainy seasons

10. Excreta disposal
 Human excreta should be disposed in sanitary
manner for protecting the public from diseases.
 Human excreta is a major source of infection as
it contain pathogenic microorganisms, viruses,
protozoa, helminthic parasites and their eggs.
 The faeces of patients contain various disease
producing agents which are transmitted through
air, food, flies, soil etc.
 It directly pollutes the water and food.
 The diseases associated with its improper
disposal include typhoid, diarrhoea, dysentry,

11.  Methods for disposal of human excreta
(1)Rural and unsewered areas
 Service type
 Non service type
(2)Sewered areas
 Water carriage system and sewage treatment

12. Service type latrines:
 Human excreta is collected from privies(a toilet
located in a small shed outside a house) and latrines
by manual labour in buckets and transferred into night
soil carts for transportation to distant places for final
disposal.
 This system is called service type or conservancy
system and such latrines are called service type
latrines.
Drawbacks of service type latrines:
 Human excreta is exposed to flies even in carts.
 Soil and water pollution
 Some quantity of excreta remains sticking to the
buckets.

13. Non service type latrines
 It includes:
a) Bore hole latrine
b) Dug well latrine
c) Water seal latrine
d) Shallow trench latrine
e) Deep trench latrine
f) RCA latrine(Research Cum Action project,
Govt of India)

14. Water carriage system (sewage system)
 Human excreta is collected and removed along with
waste water through underground pipes known as
sewers to a distinct place for final disposal.
 Sewage include excreta, urine, waste water from
houses, commercial establishments, factories,
stables & rain water.
 Requires lot of money to lay down the underground
system of pipes and to maintain them.
 Advantages of sewage system:
1. No manual labour for excreta removal
2. Latrines always remain clean
3. No nuisance of smell or flies
4. Disease spreading by insects, rodents or animals is