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AQA A-level Environmental science Comprehensive Review
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AQA A-level Environmental science Comprehensive Review
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AQA A-level Environmental scienceComprehensive Review
LCA (lifecycle analysis) - Answer>> analysing the entire
lifecycle from obtaining the raw materials to disposal. e.g.
fluorescent light bulbs use less energy, but they use polluting
material such as mercury, not found in incandescent light bulbs.
spectroscopy - Answer>> The study of the properties of light
that depend on wavelength.
Remediation of contaminated land - Answer>> 1. Preliminary
site investigation
2. Intrusive on-site investigation, risk assessment, collection,
testing etc
3. Remediation works, technology is selected after a CBA
4. Verification and validation, monitoring to ensure all targets have
been met
Surfactant Enhanced Aquifer Remediation (SEAR) - Answer>>
A method of injecting surfactants into the subsurface to desorb
pollutants and recovery.
In Situ Oxidation - Answer>> Oxygen or air can be injected into
anaerobic environments to allow aerobic bacteria to work on the
pollutants. Speeds up removal as aerobic is faster than
anaerobic. Hydrology of the area is considered as there can be
the unwanted side effect of distributing the pollutants further if the
groundwater flow isn't suitable.
Pump and treat - Answer>> Useful for petroleum contaminated
groundwater, where activated carbon is used.
,Flocculant - Answer>> A substance which promotes the
clumping of particles, especially one used in treating waste water.
Surfactant - Answer>> A substance that tends to reduce the
surface tension of a liquid in which it is dissolved.
Air stripping - Answer>> VOCs are separated from groundwater
by exposing water to air (the VOCs evaporate due to their high
vapor pressure). Pollutants with relatively high Henry's Law
coefficients can be economically stripped from water.
Henry's Law Coefficient - Answer>> The ratio of the
concentration in air that is in equilibrium with its concentration in
water. Henry's law coefficient increases with temperature;
therefore it follows that air stripping is easier at warmer
temperatures.
Solidification and Stabilisation - Answer>> The addition of a
binder to prevent the mobility of the pollutants. Designed to
produce more chemically stable pollutants, and solidification
changes the state of the liquid to contain them in the soil.
Expensive, not easy to remove the contaminated soil, also some
stabilised compounds may be left .
Soil Vapour Extraction (SVE) - Answer>> Both groundwater
and soil can be remediated at the same time, used with multi-
phase extraction (MPE) to treat VOCs. Granulated activated
carbon can be used, as it readily absorbs and also can be
positively charge to absorb ions such as chlorine, fluorides, ozone
etc.
Thermal oxidation is used in conjunction with SVE - Answer>>
Controlled high temperature incineration of exhaust gases to
,oxidise the contents of a vapour stream, but it can release dioxins
if not used at sufficiently high temperature.
Nanoremediation - Answer>> nano-sized agents that can
degrade or stabilise pollutants. work through redox reactions and
can immobilise lead or arsenic. Mostly used for groundwater
treatment, but others are being researched. They have a large
surface area which can speed up the process, but are very
reactive and can clump together, or react with other materials in
the area.
Redox Reaction - Answer>> an oxidation reaction paired with a
reduction reaction. The transfer of electrons .
Aromatic hydrocarbon - Answer>> hydrocarbon consisting of
closed rings of carbon atoms
Collapsing Air Bubbles - Answer>> An experimental
technology. Air microbubbles created in water in the absence of a
surfactant might be used to clear oil contamination.
Satellite: TEMPO - Answer>> Tropospheric Emissions:
Monitoring of Pollution. Measure the pollution concentrations in
the troposphere many times a day.
Elwha River - Answer>> 2 HEP dams, blocking the migratory
route for the keystone species, the salmon. Populations
decreased and other species also dwindled, so Elwha River
Ecosystem and Fisheries Restoration Act was passed in 1992.
The Loess Plateau - Answer>> An area the size of France of
grassland and forest system was dried out, leaving a barren
landscape. Large areas were successfully restored though, due to
, them differentiating ecological and economical land. More was
dedicated to ecological, but this actually increased productivity.
Edaphic factors - Answer>> Factors relating to the soil, e.g.
depth or pH.
Endemic pests - Answer>> These are always around, they
generally exist in small or moderate numbers
Epidemic pests - Answer>> Not native to the area and multiply
rapidly causing problems.
Introduced pest - Answer>> These are pests that have come
from elsewhere, but they may have arrived in a new area in a
consignment of produce
Mycorrhyzal fungi - Answer>> Network in soil gives nutrients to
plant roots and sugars are returned to the fungi.
Abiotic limiting factors in farming - Answer>> Nutrient and water
supplies; Temperature; Light; Acidity; Carbon Dioxide
Biotic limiting factors in farming - Answer>> Control of
population, both of what you are farming and pests; Reduction of
competition by other species and pests; Control of disease;
Increasing quality of soil biota; Encouraging pollinating insects.
What statistic was shown on The World Wildlife Fund Living
Planet report, 2016 - Answer>> Wildlife populations have
reduced by about 58% between the years 1970 and 2012.
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