Environmental Science Notes
Acid Mines, Heavy Metals & Landfill
Acid Mine Drainage (AMD)
AMD refers to the outflow of acidic water from mines (coal, hardrock, etc.).
It's a significant environmental problem that can persist indefinitely, even after mining stops.
Causes of Acid Mine Drainage
Sulphide Mineral Oxidation
Exposure of sulphide minerals (e.g., pyrite – iron sulphide) to water and oxygen.
Results in sulphuric acid and iron hydroxide production, along with heavy metals.
Water Infiltration
Water (rainfall, surface water) infiltrates mine workings.
Reacts with exposed sulphide minerals, continuing acid production.
Microbial Activity
Bacteria (e.g., Thiobacillus ferrooxidans) catalyse sulphide oxidation, accelerating AMD formation.
Mining Activities
Mining exposes a greater surface area of minerals.
Creates waste rock and tailings with high potential to generate acid.
Impacts of AMD
Aquatic Ecosystems
Acidic waters (pH ≤ 4) can be lethal to aquatic organisms.
Causes direct mortality to fish and invertebrates, disrupts reproductive cycles.
Heavy metals (cadmium, lead, mercury) are toxic, leading to bioaccumulation and biomagnification.
Soil
Acidic soil inhibits plant growth, releases aluminum from soil clays (toxic to plants).
High heavy metal concentrations are detrimental to plant health.
Water Contamination
Contaminates drinking water sources, making water unsafe without treatment.
Corrodes water pipes.
Soil Structure
Destroys soil structure, leading to loss of fertility.
Contaminated sediments become long-term hazards.
Human Health
Direct/indirect impacts via contaminated water supplies with heavy metals.
Can lead to various health issues if consumed or entering the food chain.
Economic Impacts
Costly cleanup, decreased property values.
Increased costs for water-using industries (agriculture, fisheries) due to added treatment needs.
Addressing AMD
Prevention
Careful planning and management of mine waste.
Use of impermeable barriers to minimise water exposure.
Treatment
Lime neutralisation: adding alkaline substances to raise pH and precipitate metals.
Containment
Constructed wetlands: using natural processes to neutralise acidity and remove metals.
Water Management
Diverting surface water and reducing oxygen infiltration.
Prevention and early intervention are key.
Research into passive treatment systems, phytoremediation, and metal recovery.
Monitoring Water Pollution
Essential for ensuring aquatic ecosystem health and availability of clean water.
Indicators and Tests
Biological Oxygen Demand (BOD)
Definition: Amount of oxygen required by aerobic microorganisms to break down organic material in water at a specific temperature (usually 5 days at 20°C).
Process: Water sample is sealed and incubated in the dark at 20°C for 5 days. Dissolved oxygen (DO) is measured initially and after incubation. The difference indicates BOD.
Significance: High BOD indicates high organic matter levels and potential for hypoxia (aquatic life die-offs).
Chemical Oxygen Demand (COD)
Definition: Total quantity of oxygen required to chemically oxidise all organic, inorganic, and oxidisable material in water.
Process: Water sample is treated with a strong chemical oxidant (e.g., potassium dichromate in strong acid), and the amount of oxidant consumed is measured (usually via titration or colorimetry).
Significance: Measures both biodegradable and non-biodegradable organic matter. Faster test than BOD.
Coliform Count
Definition: Measure of the number of coliform bacteria (found in soil, surface water, and digestive tracts of animals) in water.
Process: Water samples are incubated with a nutrient medium to promote coliform growth. Colonies are counted using membrane filtration or multiple-tube fermentation.
Significance: High coliform counts indicate potential contamination with pathogenic bacteria and fecal matter, posing a risk to human health.
Biotic Indices
Definition: Evaluate water quality based on the presence and abundance of certain aquatic organisms (macroinvertebrates).
Process: Samples of the biological community are collected and identified. Their presence and abundance provide a biotic index score indicating pollution level.
Significance: Provides a nuanced picture of the ecological status of a water body over time, accounting for biological responses to pollution.
Additional Considerations
Physical Parameters: Temperature, turbidity, and pH levels.
Nutrient Levels: High levels (nitrates, phosphates) indicate potential eutrophication.
Heavy Metals and Chemicals: Monitored due to harmful effects on life and the ecosystem.
Monitoring Techniques and Technology
Automated Sampling and Sensors: Real-time monitoring of water quality.
Remote Sensing and Drones: Monitoring larger areas and identifying pollution sources.
Factors to Consider for Methodologies
Type of pollutant, concentration, water matrix, cost, available resources, regulatory requirements, monitoring purpose, frequency, data quality, and ease of use.
Heavy Metals
Significant source of environmental pollution due to persistence and bioaccumulation.
Examples: mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As).
Impact Influenced by Properties
Liposolubility (Lipophilicity)
Ability of a substance to dissolve in fats, oils, and lipids.
Lipophilic heavy metals accumulate in fatty tissues, persist, and bioaccumulate (e.g., methylmercury).
Synergism
Combined effect of two or more substances is greater than the sum of individual effects.
Heavy metals together can cause greater harm (e.g., lead and cadmium on kidney function).
Solubility
Property of dissolving in a solvent (often water).
Determines mobility and bioavailability.
More soluble metals are transported easily and readily absorbed (e.g., hexavalent chromium [Cr(VI)] vs. trivalent chromium [Cr(III)]).
Other Properties
Persistence: Do not degrade; cycle through different forms.
Bioaccumulation and Biomagnification: Accumulate in organisms and increase in concentration up the food chain.
Valency and Speciation: Toxicity varies depending on valence state and chemical form.
Environmental and Health Impacts
Ecosystem Damage: Disruption of nutrients, harm to critical organisms, contamination of resources.
Human Health Risks: Neurological damage, kidney/liver diseases, cancer, vulnerability of children and pregnant women.
Food Supply Contamination: Accumulation in crops and animals, making food unsafe.
Heavy Metal Sources, Health Effects (Table 2)
Lead: Batteries, paint, mining, smelting. Damage to nervous system, kidneys, and blood.
Arsenic: Pesticides, mining, smelting. Cancer, skin lesions, neurological damage.
Mercury: Dental amalgams, coal-fired power plants, mining. Damage to the brain, nervous system, and kidneys.
Cadmium: Batteries, plastics, fertilisers. Kidney damage, lung cancer.
Chromium: Industrial processes, leather tanning, metal plating. Lung cancer, skin irritation.
Nickel: Stainless steel production, mining, smelting. Respiratory problems, skin allergies.
Copper: Mining, smelting, electrical wiring. Liver damage, Wilson's disease.
Zinc: Galvanised steel, mining, smelting. Stomach cramps, diarrhea.
Iron: Mining, smelting, steel production. Iron deficiency anemia.
Controlling Heavy Metal Pollution
Aimed at reducing release, minimising exposure, and remediating sites.
Lead
Regulations and Bans: Reduced/banned use in paints, gasoline, piping, and solder.
Substitution: Developing alternatives in batteries and ammunition.
Remediation: Phytoremediation, soil washing, or stabilisation.
Monitoring and Testing: Regular testing, especially in areas with old plumbing or former industries.
Mercury
Minamata Convention: International treaty to protect from mercury emissions.
Best Management Practices: Prevent mercury release during extraction and processing.
Reduction in Coal Burning: Transitioning to cleaner energy sources.
Safe Disposal: Correct disposal of mercury-containing products.
Cadmium
Industrial Regulation: Control measures on emissions and recycling cadmium-containing wastes.
Agricultural Practices: Controlling application of phosphate fertilisers.
Food Safety: Monitoring levels in food products.
Soil Remediation: Liming to reduce cadmium uptake by plants.
Tin
Organotin Regulation: Banning organotin compounds in antifouling paints.
Recycling Programs: Promoting recycling tin and tin compounds.
Product Formulation: Developing alternatives to organotin stabilisers.
Iron
Water Treatment: Removal using filtration, aeration, and chemical precipitation.
Pipe Maintenance: Replacing old pipes to reduce leaching.
Best Practices in Mining: Proper management of mine tailings and waste.
General Strategies
Pollution Prevention: Reducing/eliminating pollutants at the source.
Waste Treatment: Treating effluents to remove heavy metals.
Environmental Legislation: Strict standards and regulations.
Public Education: Raising awareness and promoting safe use/disposal.
Clean Technology: Investing in cleaner production.
Monitoring and Surveillance: Regular environmental monitoring.
Effective control requires technological, regulatory, and educational approaches, with international cooperation.
Solid Wastes
Types of Solid Waste Pollutants
Domestic Waste: Household garbage.
Industrial Waste: Chemicals, metals, and non-biodegradable materials.
Construction and Demolition Debris: Concrete, wood, metals, and plastics.
Electronic Waste (E-Waste): Toxic substances such as lead, mercury, and cadmium.
Medical Waste: Biohazardous materials, pharmaceuticals, and chemicals.
Agricultural Waste: Organic waste, pesticides and fertilisers.
Impact on Environment
Soil
Landfills: Older landfills can leach toxins.
Illegal Dumping: Releases pollutants as they degrade.
Water
Leachate: Contaminates groundwater and surface water.
Plastics: Harm to marine life.
Air
Decomposition: Methane release.
Combustion: Toxic fumes released.
Ecosystems and Wildlife
Ingestion and Entanglement: Leading to injury, illness or death.
Habitat Disruption.
Impact on Human Health
Exposure to Toxins: Via contaminated water/food, direct contact, or polluted air.
Disease Vectors: Attracting rodents/insects that carry diseases.
Control and Management
Reduce, Reuse, Recycle: Minimising waste generation.
Proper Waste Disposal: Sanitary landfills, incinerators with pollution controls, or composting.
Regulation and Legislation: Strict waste management laws.
Education and Awareness: Informing public about impacts of waste.
Waste to Energy: Using waste to generate energy.
Hazardous Waste Management: Special handling, treatment, and disposal.
Properties of Solid Wastes
Degradability
Biodegradable (food scraps, paper): Can be composted.
Non-Biodegradable (plastics, glass, metals): Persist, can accumulate.
Conditions Affecting Degradation
Temperature: High temperatures increase microbial activity.
Moisture: Necessary for microbial activity.
pH: Affects microbial activity.
Oxygen Levels: Impacts decomposition.
Decomposers: Availability of bacteria, fungi, etc.
Flammability
Combustible Waste: Fire hazard in landfills.
Non-Combustible Waste: Challenging to dispose of.
Release of Radioactivity
Radioactive Waste: Requires careful containment and storage.
Toxicity
Toxic Waste: Hazardous chemicals toxic to humans, animals, and plants.
Inert Waste: Non-toxic, but may cause physical pollution.
Other Relevant Properties
Physical Form: Affects manageability and potential for pollution.
Chemical Compostion: Affects reactivity and contamination.
Density: High-density resists transport, low-density spreads easily.
Proper waste management requires understanding these properties to mitigate impacts.
The Impact of Affluence
Relationship between waste production and affluence.
Increased Consumption
Affluent societies have higher levels of consumption, generating more waste.
Disposable Culture
Tendency to use products once.
Product Life Cycle and Design
Planned obsolescence leads to increased waste.
Food Waste
Higher standards for aesthetic quality in food contributes to waste.
Electronic Waste
Rapid turnover of electronics = significant amounts of e-waste.
Recycling and Waste Management
Affluence increases resources for managing waste.
Environmental Awareness
Higher level of education leads to sustainable practices.
Eco-friendly Products
There is often a market in affluent societies for eco-friendly products and packaging, which can lead to reduced waste.
International Waste Trade
Transporting waste to less affluent countries shifts the pollution burden.
Increased wealth can lead to higher waste quantities, but can also provide means for better waste management and responsible consumption.
Disposing of Solid Waste
Factors Influencing Waste Disposal
Population Density
Mass of Waste Produced
Properties of Wastes
Land Availability
Economic Factors
Environmental Regulations
Technological Capability
Societal Attitudes and Behaviors
Transportation and Accessibility
Disposal by Dumping
Deliberate Dumping: Avoid disposal costs, convenience.
Accidental Dumping: Inadequate containment during transportation, natural disasters.
Understanding and addressing these factors is crucial in the development and implementation of eeffective waste management strategies that minimise environmnetal impact and promote sustainable practices
Land Fill
Features of good landfill management
Site Selection: Away from populated areas, low flood risk, and away from groundwater sources.
Liner Systems: Base liner made of clay to prevent leachate.
Leachate Collection and Treatment: Combination of drainage layer and pipes to process leachate.
Gas Collection Systems: Reduce climate change impact.
Covering and Compaction: To reduce odours.
Monitoring: Of groundwater to detect any pollution.
Access Control: Prevent disruption by public.
Aftercare: To ensure environmental safety.
Disadvantages of Landfills
Environmental Impact: Includes habitat destruction during construction.
Methane Production: Contributes to climate change.
Air Pollution: Decomposing waste can release VOC.
Resource Mismanagement: Landfilling can be seen as a waste of materials.
Land Consumption: Landfills require large areas of land.
Visual Impact: Landfills can be seen as eyesores
Long-Term Liability: Potential for future environmental problems.
Nuisance: Attract vermin and birds
Spoil Heaps
Large piles of waste rock and soil removed during mining operations.
Uses and Functions
Storage of Overburden.
Land Reclamation.
Construction Material.
Habitat Creation.
Environmental and Social Impact
Visual Impact: Affecting the aesthetic value of the area.
Stability Issues: Leading to landslides or slippage.
Pollution: Leaching minerals and contaminants into groundwater.
Dust and Wind Erosion: Polluting the air and affecting human health.
Recovery of Land: Land cannot be used for other purposes unless they are properly reclaimed.
Management of Spoil Heaps
Effective management of spoil heaps involves careful planning and engineering to ensure they are stable and don't adversely affect the environment. This includes contouring and landscaping.
Consider geotechnical assessment for stability, engineering solutions, drainage control and leachate management.
Use soil amendments and phytoremediation.
Control soil pH.
Incineration
Used to dispose of solid wastes by burning them at high temperatures.
Modern incinerators are waste-to-energy plants the generate heat during incineration, is then used to produce steam to generate electricity or provide distric heating.
Types of Incinerators
Mass Burn Incinerators: the most common where unsorted waste is burned.
Refuse-Derived Fuel (RDF) Incinerators: Waste is sorted.
Rotary Kiln Incinerators: Used primarily for hazardous or medical waste.
Incineration Process
Waste Preparation: Is sometimes sorted to remove large recyclables.
Combustion: Is fed into the incinerator's chamber where it's burned at a specific temperature. Heat can break down the water into ash.
Energy Recovery: Modern incinerators can generate electricity.
Gas Cleaning: Flue gases produced from incineration need to be treated to be released into the atmosphere.
Ash Handling: Bottom ash and fly ash is then disposed to handle heavy toxins properly.
Advantages of Incineration
Help reduces the volume of waste by up to 90%.
The process is a source of energy recovery, reducing the need for fossil fuels.
It can convert waste problems into energy solutions, contriubting to a circular economy approah.
Disadvantages and Concerns
Some emissions and particulates are inevitable.
May contain hazardous substances that require careful disposal.
The construction and operation of incinerators can be very expensive.
Often faces public opposition due to pollution and health impacts.
Good domestic waste incinerators key features:
High Temperatures: to ensure proper combustion of waste
Good Insulation: crucial to maintain high temperatures and efficiency.
emission Controls: Must have filters to capture particulate matter and acidic gases.
Secondary Combustion: to burn off any combustible gases.
Asbestos
Is classified as specialist or hazardous waste due to its potential to cause harm to human health.
Potential Dangers
harmful when inhaled because they can become permanently trapped in the lungs. Over time, these fibers can acumilate and cause inflammation and lead to severe health problems such Asbestosis, Mesothelioma or Cancer.
Handling Asbestos Waste
Before renovation, consult a professional to help identify if an asbestos is present.
Removal is only to be performed, by licensed professionals, with specialised training. They should wear respirators to prevent inhalation of fibers.
As the Asbestos is being removed, it is kept wet with its work area being sealed off, in order to contain any released fibers.
Asbestos waste must be transported in leak-tight containers by authorised personnel, in order to prevent the release of fibers.
Disposed of by landfills that accept hazardous waste.
Asbestos cannot be recycled or reused.
Cyanide Wastes
A highly toxic chemical compound used in mining and other chemical related productions.
Classified as a speacilaist waste due to extreme toxicity and potential for environmental harm and health risk associated with it's exposure. If mismanaged it can cause longterm ecological damage.
Sources of Cyanide Wasters
Mining
Metal Finishing
Chemical Production
Pharmaceuticals
Pest Control
Potential Dangers
Cyanide inhibits cell to use oxygen, causing rapid cell suffocation, leading to respiratory failure, loss of consiousness, cardiac arrest or death.
Handling Cyanide Waste
Identified and segragated from other wastes.
Waste is stored in secure containers to prevent leaks.
Neutralisation is done to reduce toxicity from waste.
The handlers must use protective clothing, gloves and masks to prevent direct contact.
Workers must undergo specialidesed training in hazardous waste handling and emergeny procedures.
Encapsulation & Vitrification
Vitrification converts materials into a stable glass form, and encapsulation is a method used to contain hazardous wastes by enclosing them in stable mediums, in order to stabilise the waste and prevent the release of contaminants into the environment.
Encapsulation
Macroencapsulation: Enclosing the waste in containrs such as drums or vaults, often immobilised within the contianer using a medium such as cement.
Microencapsulation: This involves coating or surrouding small particles of waaste with polymers to form a carrier around the waste particles.
Vitrification
The waste is mixed with glass-forming additives to be melted at high temperatures.
Upon cooling, it solidifies into a glass like material which results in the hazardous contituent being chemically bonded within the glass matrix
It is stored in suitable facilites where it is isolated from the environment.
Acid Mine Drainage (AMD)
Acidic water outflow from mines, persisting post-mining.
Causes of Acid Mine Drainage
Sulphide Mineral Oxidation: Sulphide minerals + water + oxygen = sulphuric acid, iron hydroxide, heavy metals. \FeS2 + H2O + O2 \rightarrow H2SO4 + Fe(OH)2
Water Infiltration: Water reacts with minerals, continuing acid production.
Microbial Activity: Bacteria accelerate AMD formation.
Mining Activities: Increased mineral surface area exposed.
Impacts of AMD
Aquatic Ecosystems: Acidic waters lethal to organisms; heavy metals toxic.
Soil: Inhibits plant growth, releases toxic aluminum, high heavy metal concentrations.
Water Contamination: Unsafe drinking water, corroded pipes.
Soil Structure: Destroys structure, contaminated sediments.
Human Health: Heavy metals via water/food supplies.
Economic Impacts: Costly cleanup, decreased property values.
Addressing AMD
Prevention: Mine waste management, impermeable barriers.
Treatment: Lime neutralisation to raise pH and precipitate metals.
Containment: Constructed wetlands for acidity neutralisation and metal removal.
Water Management: Diverting surface water, reducing oxygen infiltration.
Prevention and early intervention are key.
Monitoring Water Pollution
Essential for aquatic ecosystem health.
Indicators and Tests
Biological Oxygen Demand (BOD): Oxygen needed by microorganisms to break down organic material. High BOD = high organic matter, potential hypoxia.
Chemical Oxygen Demand (COD): Oxygen needed to oxidise all material in water. Measures biodegradable and non-biodegradable matter. Faster than BOD.
Coliform Count: Coliform bacteria number in water. High counts indicate pathogen contamination, risk to human health.
Biotic Indices: Evaluate water quality via aquatic organisms. Provides an ecological status picture over time.
Additional Considerations
Physical Parameters: Temperature, turbidity, pH.
Nutrient Levels: High levels (nitrates, phosphates) indicate eutrophication.
Heavy Metals and Chemicals: Harmful effects monitored.
Monitoring Techniques and Technology
Automated Sampling and Sensors: Real-time monitoring.
Remote Sensing and Drones: Monitoring large areas, identifying sources.
Factors to Consider for Methodologies
Type of pollutant, concentration, water matrix, cost, resources, regulations, purpose, frequency, data quality, ease of use.
Heavy Metals
Environmental pollution due to persistence and bioaccumulation. Examples: mercury (Hg), cadmium (Cd), lead (Pb).
Impact Influenced by Properties
Liposolubility: Accumulates in fatty tissues, persists, bioaccumulates (e.g., methylmercury).
Synergism: Combined effect is greater than individual effects (e.g., lead and cadmium on kidney function).
Solubility: Determines mobility and bioavailability. More soluble = easily transported/absorbed (e.g., hexavalent chromium [Cr(VI)]).
Other Properties
Persistence: Do not degrade.
Bioaccumulation and Biomagnification: Accumulate in organisms, increase up the food chain.
Valency and Speciation: Toxicity varies.
Environmental and Health Impacts
Ecosystem Damage: Disruption of nutrients.
Human Health Risks: Neurological damage, kidney/liver diseases, cancer.
Food Supply Contamination: Accumulation in crops and animals.
Heavy Metal Sources, Health Effects
Lead: Batteries, paint, mining. Nervous system, kidneys, blood damage.
Arsenic: Pesticides, mining. Cancer, skin lesions, neurological damage.
Mercury: Dental amalgams, power plants, mining. Brain, nervous system, kidney damage.
Cadmium: Batteries, plastics, fertilisers. Kidney damage, lung cancer.
Chromium: Industrial processes. Lung cancer, skin irritation.
Nickel: Stainless steel production, mining. Respiratory problems, skin allergies.
Copper: Mining, electrical wiring. Liver damage.
Zinc: Galvanised steel, mining. Stomach cramps, diarrhea.
Iron: Mining, steel production. Anemia.
Controlling Heavy Metal Pollution
Lead
Regulations and Bans: Reduced/banned use.
Substitution: Developing alternatives.
Remediation: Phytoremediation, soil washing, stabilisation.
Monitoring and Testing: Regular testing.
Mercury
Minamata Convention: Protect from emissions.
Best Management Practices: Prevent release during processing.
Reduction in Coal Burning: Cleaner energy sources.
Safe Disposal: Correct disposal.
Cadmium
Industrial Regulation: Control measures on emissions.
Agricultural Practices: Controlling fertilisers.
Food Safety: Monitoring levels.
Soil Remediation: Liming.
Tin
Organotin Regulation: Banning compounds in paints.
Recycling Programs: Promoting recycling.
Product Formulation: Developing alternatives.
Iron
Water Treatment: Removal using filtration.
Pipe Maintenance: Replacing old pipes.
Best Practices in Mining: Proper management of tailings.
General Strategies
Pollution Prevention: Reducing pollutants at the source.
Waste Treatment: Treating effluents to remove heavy metals.
Environmental Legislation: Strict standards and regulations.
Public Education: Raising awareness.
Clean Technology: Investing in cleaner production.
Monitoring and Surveillance: Regular monitoring.
Solid Wastes
Types of Solid Waste Pollutants
Domestic, industrial, construction, electronic, medical, and agricultural waste.
Impact on Environment
Soil: Landfills leach toxins, illegal dumping releases pollutants.
Water: Leachate contaminates water, plastics harm marine life.
Air: Decomposition releases methane, combustion releases toxic fumes.
Ecosystems and Wildlife: Ingestion/entanglement leads to injury, habitat disruption.
Impact on Human Health
Exposure to Toxins: Via contaminated water/food, direct contact, or polluted air.
Disease Vectors: Attracting rodents/insects.
Control and Management
Reduce, Reuse, Recycle: Minimising waste.
Proper Waste Disposal: Sanitary landfills, incinerators, composting.
Regulation and Legislation: Waste management laws.
Education and Awareness: Informing public.
Waste to Energy: Using waste to generate energy.
Hazardous Waste Management: Special handling.
Properties of Solid Wastes
Degradability
Biodegradable: Can be composted.
Non-Biodegradable: Persist.
Conditions Affecting Degradation
Temperature, moisture, pH, oxygen levels, decomposers.
Flammability
Combustible: Fire hazard.
Non-Combustible: Challenging to dispose of.
Release of Radioactivity
Radioactive Waste: Careful containment.
Toxicity
Toxic Waste: Hazardous to humans, animals, plants.
Inert Waste: Non-toxic, physical pollution.
Other Relevant Properties
Physical Form, Chemical Composition, Density.
The Impact of Affluence
Increased Consumption
Affluent societies generate more waste due to higher consumption.
Disposable Culture
Tendency to use products once.
Product Life Cycle and Design
Planned obsolescence increases waste.
Food Waste
High standards for aesthetic quality contribute to waste.
Electronic Waste
Rapid turnover = significant e-waste.
Recycling and Waste Management
Affluence increases resources for managing waste.
Environmental Awareness
Higher education leads to sustainable practices.
Eco-friendly Products
Market for eco-friendly products in affluent societies reduces waste.
International Waste Trade
Transporting waste shifts pollution burden.
Disposing of Solid Waste
Factors Influencing Waste Disposal
Population Density, Mass of Waste Produced, Properties of Wastes, Land Availability, Economic Factors, Environmental Regulations, Technological Capability, Societal Attitudes and Behaviors, Transportation and Accessibility
Disposal by Dumping
Deliberate and Accidental Dumping
Land Fill
Features of good landfill management
Site Selection: Away from populated areas and groundwater sources.
Liner Systems: Clay base liner to prevent leachate.
Leachate Collection and Treatment: Drainage layer and pipes to process leachate.
Gas Collection Systems: Reduce climate change impact.
Covering and Compaction: Reduce odours.
Monitoring: Of groundwater.
Access Control: Prevent disruption.
Aftercare: Environmental safety.
Disadvantages of Landfills
Environmental Impact: Habitat destruction.
Methane Production: Contributes to climate change.
Air Pollution: VOC release.
Resource Mismanagement: Wasting materials.
Land Consumption: Requires large areas.
Visual Impact: Eyesores.
Long-Term Liability: Potential environmental problems.
Nuisance: Attracts vermin.
Spoil Heaps
Large piles of waste rock and soil from mining.
Uses and Functions
Storage of Overburden, Land Reclamation, Construction Material, Habitat Creation.
Environmental and Social Impact
Visual Impact: Affecting aesthetics.
Stability Issues: Landslides.
Pollution: Leaching contaminants.
Dust and Wind Erosion: Polluting air.
Recovery of Land: Land unusable if not reclaimed.
Management of Spoil Heaps
Careful planning and engineering, contouring and landscaping.
Incineration
Disposing of solid wastes by burning them at high temperatures.
Types of Incinerators
Mass Burn, Refuse-Derived Fuel (RDF), Rotary Kiln Incinerators.
Incineration Process
Waste Preparation, Combustion, Energy Recovery, Gas Cleaning, Ash Handling.
Advantages of Incineration
Reduces waste volume, energy recovery.
Disadvantages and Concerns
Emissions, hazardous substances, expensive, public opposition.
Good domestic waste incinerators key features:
High Temperatures, Good Insulation, emission Controls, Secondary Combustion
Asbestos
Specialist or hazardous waste due to health harm.
Potential Dangers
Harmful when inhaled, causing inflammation and severe health problems.
Handling Asbestos Waste
Consult a professional before renovation to identify asbestos.
Removal by licensed professionals with respirators.
Keep asbestos wet and seal off work area.
Transport in leak-tight containers by authorised personnel.
Dispose of by landfills that accept hazardous waste.
Cyanide Wastes
Highly toxic chemical compound used in mining and other production.
Sources of Cyanide Wasters
Mining, Metal Finishing, Chemical Production, Pharmaceuticals, Pest Control
Potential Dangers
Inhibits cell to use oxygen, causing rapid cell suffocation.
Handling Cyanide Waste
Identified and segragated from other wastes.
Store in secure containers.
Neutralisation.
Use protective clothing, gloves and masks.
Specialised training required.
Encapsulation & Vitrification
Vitrification converts materials into glass, encapsulation contains hazardous wastes.
Encapsulation
1.