Waste Management Flashcards
Waste classification
Controlled
Non controlled
Consts a scrap matln effluent or other unwanted surplus substance
Requires to be disposed of as being broken, worn out, contaminated or spoiled. Does not include explosives
Waste
Controlled waste
Household Industrial Clinical Commercial Hazardous
Non controlled waste
Agricultural
Mines and quarries
Types of refuse
Garbage Rubbish Ashes Street sweepings Dead animals Solid industrials wastes
Putrscible; wastes from handling of food; most valuable refuse - for animal feeding, home feeding, fertilizers & soil conditioners
Garbage
Non putrescible; combustible & non combustible; useful - converted into packing matls
Rubbish
Results from coals or fuels
Ashes
Leaves, dirt, sand, animal manure
Street sweepings
- Proper disposal of wastes
- works toward reduction, reuse, recycling of all sources
Waste mgmt
Objectives of waste mgmt
- Prevent contamination of : surface soil and water, ground water
- Prevent the creation of breeding place
- Prev odors and unsightly cond
- Prev cont of fomited and other objects
Heirarchy in waste mgmt
Reduction
Re use
Recovery
Disposal
- prevention of waste at source
an overall waste management strategy that seeks to reduce the amount of waste generated at each stage of a product’s life span
Waste reduction
Objectives of waste reduction
- ensure efficient use of resources
- reduce hazardousness
putting an item to another use after its original function has been fullfilled
Waste re-use
Types of re-use
Conventional - product is used a number of times before being discarded
Alternative - other uses are found for products
Waste is converted into a usable from, or energy is derived out of it
Waste recovery
Subcategories of waste recovery
Recycling - processing waste into usable raw matl
Composting - aerobic processing of organic wastes; produces stable, granular matl containg plant nutrients
Energy recovery - energy in waste is extracted in the form of fuel or electric power
Last option in the waste heirarchy
- land filling
- incineration
- permanent storage
Waste disposal
Methods of refuse disposal
Burial (1m x 1m pit)
Open burning - rural areas
Feeding
Composting - anaero/aero
Sanitary landfill- large scale burying, affects ground water
Incineration - cntrld burning, air pollution
Waste that can be land filled safely
Inert Biodegradable Aq liquids Sludges Certain special wastes
Most acceptable
Equipped wt water and transport facilities
Ex: cistern flush toilets connected to sewerage system
CATEGORY I
adv - excellent health benefits, convenience
disadv - large water req, high const and maint cost
Acceptable form
Disposal unit equipped w/ water supply
Ex Cistern flush toilet connected to septic tank Aqua privy Pour flush latrine Vault privy
CATEGORY II
adv - excellent health benefits, convenience
disadv - reqs dislodging every 1-5 years
Unacceptable form
Equipped with transport facilities only
Ex: bucket latrine
CATEGORY III
Adv: min water req, min const cost
Disadv: periodically emptied by nightsoil laborer/savenger, odor, insect, spillage
Most unacceptable
Not equipped with water nor transport facilities
Ex
Pit latrine
Bored-hole latrine, compost latrine
CATEGORY IV
Adv: convenience, very minimal const cost
Disadv: problem of env contamination that can be detrimental to health
Methods of excreta disposal/ water-carried waste in RURAL AREAS
Pit privy
Bored hole Latrines Box and carry Can privy Flying saucer
Excreta disposal in SUB-URBAN AREAS
Septic tank
Excreta disposal in URBAN AREAS
Sewerage system
Imhoff tank
Chemical toilet (5-10-15 gal water w/ 25lbs caustic soda)
Excreta disposal for VEHICLES
Chemical toilet
Steps in sewerage system
- Removal of large solid -screening bars
- Sedimentation - inside tanks
- Anaerobic decomposition - inside tanks
- Aerobic decomposition - trickling filter
- Drying of sludges - in-sludge beds
- Disinfection of effluent - uses lime before and after final disposal
Household solid waste disposal
- Burning
- Burying
- Composting
Community solid waste disposal
- Incineration
- Sanitary landfill
- Composting
