Waste Management

 

Chapter: three

Waste Management

 

Definition of terms Unwanted ed substance/material( substance/material( solid, Waste: Unwant liquid, gases) for the time being. Solid waste waste The waste that includes any garbage, refuse, sludge from waste and water treatment plants, or air pollution control facilities and other discarded materials It does not include solid or dissolved material in domestic sewage •

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Sewage •

Consists of the liquid wastes from house-hold effluents, commercial effluents, effluents, and industrial liquid wastes. wastes.

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It is carried in a system of pipes and other means of conveyance called a sewage system.

 

Garbage: •

Decomposable wastes resulting from growing, handling, preparing, cooking and consumption of food

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It needs careful handling because  –

attracts insects and helps for the breeding of files and other  –

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supply food for rats and for other vermin’s

produce unpleasant odor as result of decomposition

 

Rubbish •

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Denotes all non decomposable wastes ex except cept Ash. It consists both combustible and non combustible subst s ubstances. ances. It creates nuisance if it is not properly handled.

Ashes •

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Are waste waste product of coal and other fuels They are non- decom decomposable posable was wastes tes

Night soil •

Excreta that has been collected from box, toilet and privy. Can be used as fertilizer

 

Liquid waste •

Is essentially the water supply of community

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after it has been fouled by variety of uses. It has adverse effect to human health and the environment if it is not managed properly.

 

Sources of community waste

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Households

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Health care industries Commercial areas

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Recreational Recrea tional areas

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Industrial area

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How wastes generated in the community? wastes are generated in the form of •

garbage

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refuse street cleanings

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human and animal discharges

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kitchen wastes etc.

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Challenges in waste management The problem of wast waste e management is relative to times because as the time goes: •

The population to land mass ratio increases, as result quantity of waste produced increased

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Complexity of the waste increases

 

Classification of waste The broad classification of waste waste are:  –

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Solid waste Liquid waste

 

Solid waste management •

is the process by which workable alternative programs and plans are developed to solve solid waste problems.  –

Types of solid waste

1. Residential which include Food waste, Ashes, rubbish, sludge’ sludge’ss etc. 2. Commercial include Hazards wastes, paper products, food waste, & fire residues (Ashes) etc

 

3.Municipal •

Street sweepings, dead animals, card boards and Animal waste

4.Infectious waste •

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Is suspected to contain pathogens (bacteria, viruses, viruses , parasites, or fungi) in sufficient concentration concentration or quantity to cause disease in susceptible hosts.

This category includes: Cultures ,Excreta, dressings from infected or surgical wounds etc

 

5. Pathological waste •

Pathological wastes consist of tissues, organs, body parts, human fetus and animal carcasses, blood, and body fluids

6.Sharps •

are items that could cause cuts, or puncture wounds,

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including needles, knives, saws, broken broken glass, and nails. Whether or not they are infected, such items are usually considered as highly hazardous health care waste.

 

7. Pharmaceutical waste •

Includes expired, unused, spilt, and contaminated pharmaceutical products, drugs vaccines, and sera that are no longer used.

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Required and need to be disposed of appropriately

 

Public health importance The proper storage at the points of generation, generation, collection and disposal of the refuse is part of the environmental health service which must be accomplished effectively in a community. If domestic or community refuse is not disposed dispos ed of properly, it crate many problems

 

Improper disposal solid waste can crate the following conditions: attractive attr active media for the growth and multiplication of •

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flies. a good harborage for rats. bad odor, unsightly conditions etc. Possible fire hazards by instantaneous instantaneous combustion Pollution and contamination of natural natural environment ( water,, air or land) water la nd)

 

Functional Elements of solid Waste management sy system stem •

There are six functional elements in the activities associated with the management of solid wastes from the point of generation to final disposal site. These are:

1. Waste generation 2. On-site handling, storage storage and processing 3. Collection

4. Transfer and transport 5. Processing and recovery 6. Disposal

 

Solid waste waste disposal methods •

Incineration

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Sanitary land fill

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Controlled dumping Hog feeding for garbage

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Open dumping

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Incineration Incineration: is a high temperature dry oxidation process that reduces organic and combustible

waste to inorganic, incombustible matt m atter er and resulting in a very significant reduction of waste volume and weight.

 

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Waste types not to be incinerated: •

Pressurized gas containers

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Large amount of reactive chemical waste Silver salt and photographic or radiographic wast wastes es

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Halogenated plastics such as polyvinyl chloride (PVC)

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Waste Was te with high mercury or cadmium content, such as broken brok en thermometers, t hermometers, used batteries

 

Sanitary landfill  •

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A method of disposing a refuse refuse on land without creating nuisances or hazards to public health or safety. The characteristics characteristics of sanitary landfill that distinguish it from an open dump are the waste is placed in a suitably selected and prepared land fill site in a carefully prescribed manner, the waste materials is spread out and compacted with appropriate heavy machinery and the waste is coveredeach day with a layer of compacted soil.

 

open dumping - Disposa Disposall of waste waste iin n open field field.. -The most insanitary disposal method.

 

Health care waste management methods •

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Incineration Placenta pits Controlled dumping

 

Liquid waste management Definition of terms: •

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Sanitary sewage /domestic sewage: contains human wastes and wastewater from homes, public buildings or commercial and industrial establishments. Industrial sewage: is the used water from manufacturing processes, usually carrying a variety of chemical compounds, Storm sewage, or storm water : is the surface run off caused by rainfall

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Excreta: the waste matter mainly faeces and urine eliminated from the body.

 

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Liquid waste is the water supply of a community after it has been fouled by variety of uses. It I t may contain: disease causing org organisms anisms •

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toxic to xic chemicals

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organic org anic materials and nutrients

 

Effect of indiscriminate discharge of liquid waste 1. Pollution of water supply sources 2. Emission of malodorous malod orous gases from from accumulated wastes. wastes. 3. Unsightly condition 4. Crate favorable conditions for disease transmission.

 

Immediate and nuisance free removal of liquid is essential •

To protect public from different types of disease.

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To prevent contamination of ground and

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surface water To preserve fish and wild life population

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To maintain attractiveness of the area

 

Disposal Methods of human waste/excreta The purpose purpose of human excreta excreta disposal include: To prevent contamination of water sources (surface and ground). •

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To prevent contamination of surface – soil. To prevent accessibility of flies and other animals to human wastes

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To avoid or minimize the direct handling of fresh excreta. To provide privacy and convenience. To eliminate bad odor, which attract flies, and the unpleasing sight of areas.

 

Common methods of human waste/ex waste/ excreta creta dispos disposal al methods •

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Non- water water carriage carriage ssyst ystem: em: is a system which normally does not use water for carrying awa away y or transporting human wastes wastes Water carriage system: the excreta are deposited directly into properly constructed sanitary fittings, and are then carried away by

water through through a closed piping system (drainage) to the final disposal site.

 

Non-water carriage carriage syst systems ems 1. The pit latrine: is a hole dug in the ground according to specified dimensions, and usually

provided with means for squatting or sitting. It is mostly circular in shape, 80120 cm in diameter and 2.5-5m depth. •

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It may need squat hole cover to avid fly breeding There may be problem of odor

 

2. The ventilated improved pit latrine (VIPL): it is a modification of pit latrine, but had additional refinements to prevent prevent the development of fly population and to control odor. Vent pipe is installed which extends from from the top of the pit to up to 50 cm cm abov above e the roof of the latrine.

 

How the VIP latrine eliminate odor

 

3. Deep Trench latrine it is a variation of the pit latrine, dug in the  form of a trench or ditch in one horizontal level. It is used in army camps, in settlement sites, work camps etc, where many people live

in a communal way of life. It has dimensions of 60-90 cm width, 2-3m depth and 3m length

 

4.  The shallow trench/ shallow hole latrine: trench should be dug 25-30 cm wide, 60 cm deep, and as lSohnogveals o dressirceodop(desh po en geonpltahceednuim erso)f.   ud ldinb n beearco hf puisle earth and each person after relieving himself should immediately cover the excreta by the dug earth. Soldiers, boy scouts or school clubs, campers, worshippers at festival sites , etc, as a temporary measure, use this type of latrine and very suitable for people who are on movement

 

5.  The compost latrine or double   –  vault   vault latrine: it is a latrine with two compartments and each compartment used alternatively. When the first compartment is filled to within about 40cm from the top of the pit, it should be covered with dry earth or ashes up to the top and left undisturbed for 6- 9 months, after which the compost should be shoveled out and used as fertilizer.

 

6. Water seal (Pour- flush) latrine: •

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The essential feature differentiating it from other  systems is the specially designed squatting- plate with a trap attachment, which retains ret ains wat water er..

The squatting plate is made from cement elements. A jug or pail of water is kept in the latrine shelter After depositing excreta excreta in to the pan, each user pours water (1-3 liters) from the jug from which the name pour-flush given

 

7. Chemical toilet: it is a type of latrine which contains a solution of chemical; disinfectant  in spe specially des designe gned tank. nk. •

The tank is designed with toilet seat, with cover, flushing device and a discharge drain for bailing out the contents when the tank is full.

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T en fiascil cioem une, sed, ship n trhains spo spolarttraitnio cilit iti sm like ikoenalyirpl pla a ne hiip etc.

 

Water carriage system •

The requirements for this type of system system include piped water supply, supply, sanitary fittings or appliances inside th the e house, to receive excr excreta eta and wastewater wastewater and a network of connecting pipes to collect sewage from individu individual’ al’ss houses in a neighbor, and to convey in to the final disposal site.

 

Common liquid treatment methods - Scr Screeni eening ng : To remo remove ve lar large ge o obje bjects cts - Septic tanks - Oxida idation ion ponds nds - So Soak akag age e pit pit or seep seepag age e pi pitt - Bio-di -digesters

 

Final liquid waste disposal methods - Di Dilu luti tion on in in to to wa water bod bodie iess - La Land nd appli applica cati tion on (irr (irrig igat atio ion) n) - Evaporation