Solid Waste Management Flashcards
Define waste
Define Hazardous waste
all unused, unwanted and discarded materials including solids, liquids and gases
Hazardous waste= defined as hazardous if its flammable, toxic or carcinogenic
MSW
BMW
MSW= Municipal Solid Wastes- non-hazardous, mainly biodegradable
BMW= Biodegradable Municipal Wastes
Waste disposal options
-Landfill pre-treatment
-Recycling
-Landfill of untreated waste
Types of landfill and characteristics
Total Containment- impermeable strata
o Concentrate and contain
Slow Dispersal- permeable strata
o Dilute and disperse
o If this is unengineered can lead to ground contamination
EU Landfill directive
- Prevention
- Preparing for Re-use
- Recycling
- Other Recovery
- Disposal
What controls the environmental risks from landfill
o Waste Type
o Landfill Design
o Environmental Factors
o Management Factors
What are the environmental risk pathways from landfills
- Gases may volatilize and enter atmosphere- compounds which evaporate readily, secondary pollutants from reactions in atmosphere
- Heavy metals retained in soil
- Soluble and toxic substances pass through to groundwater system
- Surface runoff picks up leachate and transports to surface water network
- Some crops may selectively take up heavy metals- passed along food chain- biomagnification
- Transport of paper and plastic by the wind
Factors influencing gas and leachate generation in landfills
- Refuse composition density, particle size
- Temperature, pH
- Oxygen, hydrogen, sulphate, toxics, metals
- Moisture Content
- Nutrients, Microbes
Any solid fuel contains 2 combustible constituents:
- Volatile matter- released as mixture of vapours
- Solids- char (burns to produce CO2), with an inert matter (clinker/Slag)
Advantages of AD for MSW
- Gas yields much higher and digestion complete in a few weeks
- Feedstock= organic fraction of MSW, diluted into a slurry
- Can be closer to urban areas, reducing transport cost
- Requires less land
