Pollution Flashcards
Contamination
Contamination is the presence of concentrations of substances in water that are above the natural background level for that area.
Pollution
Pollution is a human activity that damages the environment.
Types of Pollutants (Name 9)
- Natural inorganic salts and sediments
- Waste heat
- Organic waste
- Ammonia
- Trace Metals
- Synthetic organic chemicals
- Persistent organic Pollutants (PoPs)
- Radioactive Materials
- Chemical and Biological Warfare agents
Types of Pollutants: Natural inorganic salts and sediments
Non-toxic but pollutant in excessive does increase turbidity, reduces photosynthesis, clog feeding and respiratory of aquatic animals. Mainly caused by soil washed off land from increased agriculture.
Types of Pollutants: Waste Heat
After cooling systems for power plants water leaves with excess low grade heat. This can affect plants thermodynamic cycles and solubility of oxygen.
Types of Pollutants: Organic Waste
Domestic sewage contains proteins, carbohydrates, fat as well as carbon nitrogen and phosphorous. Biochemical oxygen Demand (BOD) reduces, nitrates make water toxic to babies. Organic matter is oxygen demanding.
Types of Pollutants: Ammonia
Toxic to aquatic animals. It can be ionised or un-ionised.
Types of Pollutants: Trace Metals
Salts of heavy metals such as copper, silver, mercury, lead, zinc, cadmium are naturally present, but have toxic combination in waste water.
Types of Pollutants: Synthetic organic chemicals
Slow to degrade and bioaccumulated in the food chain. Waste waters are subject to high initial dilution.
Types of Pollutants: Persistent organic pollutants (PoPs)
Persist in environment for longer than intended, have low water solubility and high lipid solubility.
- Polychlorinated Bipheryls (PCBs) - absorb sediment and organic matter, cause immune dysfunction, reproductive failure and increases mortality in mammals
- Polyaromatic Hydrocarbons (PAHs) - Incomplete combustion of organic matters, cause skin cancer, liver damage and are classed as carcinogenic
Types of Pollutants: Radioactive Materials
Uncommon but highly toxic over long time scales
Types of Pollutants: Chemical and Biological warfare agents
Uncommon but toxic in very small quantities - poses great danger to life
Point Source
Definable input point e.g. pipe
Diffuse source
Has many small points or inputs such as runoff or atmospheric deposition
Sources of pollution (Name 8)
- Sewage Discharges (continuous)
- Sewage Discharges (intermittent)
- Trade Effluents
- Leaching from landfill sites and contaminated land
- Urban Runoff
- Mining
- Agricultural Runoff
- Accidents and Spillages
Sources of pollution: Sewage discharges (continuous)
Contribute to degradable organic matter, plant nutrients and microorganisms. UK sewage is treated by still has an impact.
Sources of pollution: Sewage discharges (intermittent)
During heavy rain, volume of effluent through sewage networks increases.
Combined storm overflows (CSOs) act as pressure points and release raw effluent into the environment preventing inundation of sewage treatment works (STW) releasing organic matter, nutrients and microbiological pollutants.
Sources of pollution: Trade Effluents
Controlled by Integrated Pollution Prevention and Control (IPPC)
Sources of pollution: Leaching from landfill sites and contaminated land
Rainfall leaches toxic and organic substances from unsealed landfill, polluting ground and surface water slowly.
Sources of pollution: Urban Runoff
Water from car parks, stress and industrial premises contain organic matter, rubber, hydrocarbons, metals and particulate matter.
Sources of pollution: Mining
Sources of solids, chemicals and metals. Abandoned mines fill with acid water containing iron. Inputs from spoil heaps and abandoned mines may diffuse inputs which are difficult to control.
Sources of pollution: Agricultural Runoff
Wide range of pollution including slurry, silage liquor, fertilisers, manure, soil. Intensive sheep grazing has been blamed for ecological changes, increased erosion and higher levels of humic coloration in drinking water.
Sources of pollution: Accidents and Spillages
These can be of catastrophic proportions, but continued small spillages can be equally damaging.
Eutrophication
Increase in nutrient levels and hence in biological productivity. This implied high levels of organic activity and heavy BOD. Nutrients from sewage and agricultural runoff can accelerate this process.
Oligotrophic waters
Low nutrient systems.
Mesotrophic waters
Medium nutrient systems
Eutrophic waters
High nutrient systems (can be naturally occuring)
What is the main Limiting Factor in fresh water and marine systems?
A deficiency of phosphorus (fresh waters) and nitrogen (marine waters) is often the limiting factor for plant growth.
Algae Bloom
Eutrophication occurs causing aquatic plants to be fertilised and grow. This can cause an algae bloom resulting in:
- oxygen depletion - greater BOD, asphyxiation, pH may rise
- ecological changes - changes in species, shade out of macrophytes
- physical obstruction - choke channels
Conservative pollutants
Mainly inorganic, stay in the same form and do not react with other substances (only reduced by dilution).
Non-conservative pollutants
Mostly organic, react with other substances so concentration is reduced by chemical or biological activity.
Pathogen
A bacterium, virus or other microorganism that can cause disease.
Toxic Pollutants
Mostly industrial, heavy metals, herbicides and pesticides.
Inert Solids
Can blanket a stream bed and remove fish.
Measuring Pollution method
- Taking water/wastewater samples on a routine basis
- A representative sample is required (grab sample or a composite sample)
- Design of Sampling Programmes
- Analysis of Samples
- Remote monitoring/sensing
