The document discusses various methods of solid waste and sewage disposal. It describes different types of latrines used for human waste disposal in rural areas, including pit latrines, borehole latrines, and aqua privies. The document also discusses bucket latrines, overhung privies, and flush latrines. It explains sewage disposal systems involving transporting liquid waste via drains, sewers, and sewage treatment plants which screen, remove grit, use sedimentation and aeration to treat sewage before disposal. Improper waste and sewage disposal can spread diseases like typhoid, worms, and hepatitis, so the document emphasizes the importance of sanitation, hygiene and sewage treatment for disease prevention.

1. Waste Management
SHAHINA BANO
Objectives
By the end of the presentation students will be able to:
• Define solid waste and sewage
• Discuss methods of solid waste disposal and sewage disposal
• discuss Latrine types
• List fecal-borne diseases and it’s control.
• Summarization
b. Sanitary Latrines:
• The place used for defecation or urination is called ‘latrine’ or ‘privy’. The qualities of a good latrine are:
• Simple in construction and in use. For example, it should have a roof, a cemented platform, and a seat.
• Locally available, and should not involve manual handling of excreta.
• It should be hygienic and sanitary, and should not lead to environmental pollution. For example: (excreta
should not pollute the ground or surface water and the soil.
• Feaces should not be exposed to flies, rodents, and animals.
• Excreta should not create the irritation due to smell or its appearance.
Types of latrines
A global field survey project under taken by the World Bank in 39 countries around the world identified the
following types of sanitary latrines.
 Pit hole latrine
 Bore hole latrine
 Aqua Privy
 Bucket latrine
 Over hung privy
 Flush latrines

2. Pit hole latrine
It is the simplest form of rural latrine. Consists of a hand dug hole in the ground covered with either a squatting or
plate. The super structure that gives privacy and protection from the elements can be made of any material
but should be strong enough to with stand the weather. It is simple in design and can be used for 5 years for 6
family members.
 It doesn’t require handling of fresh feces. It can be built during short periods like camps.
(2m deep/1m diameter)
Bore hole latrine
Is a type of pit privy is dug with a special machine (hand earth augar). A bore is 16 inches in diameter and 18 feet
deep from supra structure. Because of the depth of the hole, the excreta do not attract flies or liable to the
bacterial action
Aqua privy
It is also called as ‘septic toilet’. The aqua privy consists of a tank filled with water into which a drop pipe hanging
from the latrine floor. The excreta and the urine fall through the drop pipe into the tank where they under go
anaerobic decomposition as in septic tank. The digested sludge, which reduced to about a quarter of the volume of
the deposited excreta, accumulates in the tank and has to be removed at intervals.
(Similar in airoplanes)
Bucket latrine
• In bucket latrine the feaces are passed into a container in which there is some soil. There is supply of soil,
to sprinkle over the feces. It is not satisfactory method as it is a great source of infection and infestation.
If properly disposed in a pit then can be used as fertilizer.
Over hung privy
May be found in areas where there is plenty of water (sea, river, lake) .However, it is not considered to be
a satisfactory method. Here there is no container, but the waste is dropped directly in the water, so that the feaces
and the urine falls into it and gets disposed of by the action of tide or water flow.
Flush latrines
• It is found in many urban areas. They are expensive.
• Urine and feces are passed into the pan and it is cleaned by flushing water from a tank into the pan.
• This pan is connected to the sewage disposal system and to prevent the odors and germs coming back
into the pan from the sewage
Summarization

3. Water carriage system/ Wet method/ sewerage system:
Sewerage system involves carriage of sewage, (liquid wastes and human excreta) through a system of drains and
sewers from the point of origin (houses, institutions, and factories) to the point of disposal with the help of water.
(for example sewerage treatment Plan)
Elements of sewage treatments
❑ Water closet: Here human waste is collected and by flush system removed to the house drain.
❑ Soil pipe: It is through the pipe that the sewage is carried from water closet till the house drain.
❑ House drain: It is the pipe that runs from soil pipe to the sewer. it is underground and receives also waste
water from bath and kitchen.
❑ Inspection chamber and trap: Is underground airtight cement vault protecting home from getting sewage
again. After passing through the chamber, a trap disconnects the house drain from public sewers. It also
prevents the entry of gases into the house drain.
❑ Sewer: A public pipe which collects the sewage from the house drain and becomes the part of city’s
sewerage system.
❑ Disposal plant sewage purification: A large quantity of sewage from a total community is offensive in
smell and contains millions of bacteria. It has to be purified to protect the health of the community by a to
sewage plant for treatment.
Aims of sewage treatment plant
• Separate inorganic form of organic material.
• To dispose of sewage in healthy manner
Harmful hazards of excreta sewage
• Human excreta is a source of infection. It contains pathogenic organism (bacteria, viruses, protozoa,
helminthic parasites. Therefore, it should be disposed off in a hygienic way. The health hazards include
soil pollution, water pollution, food contamination, and breeding of flies.
Disease caused by improper disposal of waste
• Typhoid, intestinal worms, paratyphoid fever, diarrhea, cholera, dysentery, viral hepatitis, poliomyelitis

4. Prevention
Diseases can be prevented by:
• Proper sanitary latrines
• Proper hand washing
• Sewage treatment
Screening
• Floating solid is removed by a Iron bars to prevent blocking of pumps.
Removal of grit
• Inorganic solid such as sand and gravel is taken and after that it is used for road filling.
Primary sedimentation tank

5. • Sewage flows in this tank for 6-8 hours and other sewage settle down and form a black mud called sludge.
Sludge is taken in to another tank and effluent pass on further in septic tank for purification.
Secondary treatment
1.Biological treatment
Sludge carried to digestion tank where oxidation makes it dry. This last product is used as fertilizer.
2.Water in sedimentation tank is moved in aeration tank here chlorine is mixed to remove odor and reduce
bacteria and then send in to river or sea.
Community education for refuse and sewage disposal
Educate people about dangers to health and diseases spread by following:
– Dry refuse left on ground, or thrown into water
– Waste collection near houses and wells
– Defecation on the ground (need to dig hole and cover it after defecation)
– Fly breeding from excreta to food so cover food properly
– Spread of hook warm (Do not walk bare footed on soil)
– Improve environmental sanitation (clean streets, get off from refuses and flies).
– Ensure proper drainage for sullage water, and proper use of sanitary latrines
References
• Iliyas, M., & Shah, K. S. (2000). Disposal of Waste. In Iliyas, M., Malik, G.Q., Ansari, M.A., Mubasher, M.,
& Khan, I. A. (Editors). Community Medicine and Public Health. (5th
ed). pp. 601–631.