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Water: Quality and Sustainability within Australia and the World - Coggle…
Water: Quality and Sustainability within Australia and the World
Contaminants
waste water
Two million tons of sewage, industrial, and agricultural waste is released into water around the world daily
Approximately 44% of household wastewater isn't being properly treated
Chemical
heavy metals
pesticides
personal care products
comes from industrial discharge, agricultural runoff, consumer products etc
they contaminate the water with nitrates, phosphorus, soil sediments, salts and more
pathogens
bacteria, viruses, parasites, often from feces
they infect human bodies by entering through the mouth, eyes, nose, wounds and bites
mild symptoms include diarrhea, stomach cramps, loss of appetite, weight loss, nausea/vomiting, gas and dehydration
severe ones could affect the central nervous system, starting with headache, fever, nausea, or vomiting and can later result in stiff neck, confusion, loss of balance, seizures and hallucinations
microplastics
Up to 83% of tap water worldwide has been found to contain microplastics.
Only 9% of plastic waste has ever been recycled
Nano plastics that are small enough can cross cell membrane, and enter various systems in the body. The accumulation of these particles might trigger negative effects like oxidative stress responses, increased mucous secretion, disrupting the microbiota balance and more.
Leads to waterborne diseases like diarrhea, cholera, dysentery, and typhoid, all having more attribution to human deaths every year than war and similar forces of violence
aquatic trash
garbage polluting rivers, lakes, streams, and creeks are referred to as aquatic trash
when trash is misplaced, rain and wind is likely to carry it down to storm drains, streams, canals, and rivers.
could also be caused by illegal dumping in waterways. Illegal dumping is more common if there is a lack of regular trash pickup services
trash can also be blown out of overfilled trash bins or off of trash collection vehicles
wildlife in aquatic environments face the physical threats of being tangled by trash or consuming them
71% of Earth's surface is covered with water, which gives it the name of the 'Blue Planet'.
Only 0.3% of that water is usable
The other 99.7% is saltwater or unavailable being held in glaciers, ice caps or floating in the atmosphere.
Water scarcity
A lack of clean water spreads diseases, over one million deaths each year is related to unsafe drinking-water.
Water shortages directly influences food shortages
leads to migrations, people moving to find more livable conditions
water disputes leads to rising tensions between countries
some irreversible impacts it could have in the future is increased loss of biodiversity, deforestation and desertification from water shortages
it also intensifies the long term effects of climate change
what is 'water sustainability'?
the practice of managing water resources to meet the needs of the present without compromising the ability of future generations to meet their own needs
key aspects
conservation, finding strategies to use water more efficiently
preventing pollution, protecting water sources from being contaminated
treating and reusing water, since it is a limited source
Sustaining water is important in ensuring access to clean drinking water, supporting ecosystems, and maintaining agriculture and energy production for current and future generations.
By using water efficiently, we can prevent water scarcity, reduce pollution, lower energy consumption for water treatment, and protect biodiversity.
what is 'water quality?'
good water quality is vital for human health and maintaining freshwater ecosystem health
it is a critical part for managing water catchments
it affects what the water is being used for
industries like agriculture, tourism and irrigation all require good water quality for them to function
It is measured by numerous factors like pH levels, temperature, salinity, percentage of dissolved oxygen, turbidite, nutrients (levels of nitrates and phosphates) and more.
Acid sulfate soils (soil that contain metal sulfides)
They form when these criteria are fulfilled
waterlogged and/or oxygen-free conditions
a source of sulfate from seawater or saline groundwater
the presence of organic matter and metals such as iron.
these soils release acid when exposed to air, which can seriously affect water and soil quality
they can lead to reduced pH, decreased oxygen concentration in water and the release of heavy metals such as cadmium and lead, and metalloids such as arsenic
these contaminants can also enter waterways when the soils are rewetted
they affect human activities with poor water quality and releases foul odours
water purification
water purification removes impurities and 90-95% of the biological minerals present in the water, compared to a water filter, that only removes sediment and harmful chemicals and toxins
Filters
Rapid sand filters
Most common type of filters, water passes through the sand which has a layer of activated carbon right above that filters out organic compounds and improves the taste and odor of the water.
commonly used in developing countries to filter large amounts of water
Slow sand filters
This method relies on biological processes rather than physical filtration.
water flows slowly through graded sand layers with the finest at the top.
cheap to build, good when land and space are an issue, easily maintained but requires a skilled worker to operate.
Bank filtration
Operating well systems are dug in sandy sediments near water bodies, where water can be naturally filtered through the soil and easily extracted.
Usually used as the first stage of contaminant filtration, other methods such as oxidation and adsorption are required to purify it to drinking water standards.
Membrane filtration
Used to purify drinking water and sewage by preventing the spread of bacteria and viruses.
Can also remove suspended solids and sediments, commonly used for wastewater, being able to operate under pressure or vacuum.
No filtration method can remove dissolved properties such as phosphates, nitrates, ions, and heavy metals, therefore other purification methods must be used such as distillation or disinfection.
Solar purification
This is an alternative to UV disinfection methods. Uses UV radiation from the sun to treat contaminated water.
A container is filled with water, shaken to excite oxygen molecules and left horizontally in the sun. This simple process effectively kills any bacteria and viruses present in the water, making it drinkable.
When the water is exposed to UV radiation, the microorganisms cannot further breed. But a filters required to remove the impurities and heavy metals from the water.
Distillation
In the distillation process, the water is boiled until it evaporates, the water vapor is then collected into a condenser to cool. It transforms back into liquid as it cools, and made safe for drinking.
Disinfection
Chlorine
An older, yet effective technique to purify water, often used in emergencies when other methods are not available.
A mild bleach, containing ~5% of chlorine, is added to oxidize and kill microorganisms in the water.
Chlorine tablets can also be used, but must be first be dissolved in heated water
Disinfection filters harmful microorganisms and utilizes disinfectants to purify water
Chlorine Dioxide
Faster method than chlorine, purifies water through oxidation. It penetrates cell walls and removes bacteria.
Is rarely used now due to the U.S. regulations because it contains a lot of chlorite
Chloramine
Becoming more common because of a lower redox potential compared to chlorine, but is weaker than chlorine.
Water disinfected by chloramine can also be put under nitrification, which is undesirable because it depletes the disinfectant residual, which prevents future contamination, potentially leading to biofilm growth and poor water quality.
Ozone
Ozone is an unstable molecule that gives away oxygen molecules. As dissolved oxygen is toxic to most organisms, it is used to disinfect water in Europe, Canada and the U.S. to remove pathogens.
preferred over chlorine because it doesn't change the taste or odor of drinking water
However, ozone disinfection is very energy-intensive and is very reactive and corrosive. The emitted gasses must be destroyed to protect the workers.
Ultra Violet
Very effective in water with low turbidity, powerful at inactivating bacteria and viruses.
As the turbidity levels increase, the usefulness of this method decreases due to the amount of suspended solids present in the water.
it also removes all residual disinfectants, which means they'll have to be added after the disinfection process
Used daily in developing countries
Boiling
Boiling water is one of the simplest methods to do at home, since most organisms cannot survive within the water after the temperature is over 100 degrees Celsius, but it still needs to be strained later, getting rid of the dead microorganisms and impurities at the bottom of the water
Iodine
Iodine tablets or liquids can easily be added to water to kill bacteria and viruses.
It's very powerful but may add an unpleasant taste to the water, could also be lethal to humans in high concentrations
It should only be used if no other methods are available.
Ground water
ground water is water that underlies the Earth's surface
2% of the Earth's water is groundwater, which makes up approximately 17% of accessible water resources and over 30% of total water consumption
Some is naturally fresh and drinkable while others are at varied levels of saltiness, some even contain high levels of dissolved chemicals that renders them unconsumable
It's sustainability is currently being threatened by over extraction.
It's quality is being affected by pollution from human activities, its slow movement compared to fast rapid rivers means pollution can remain in the aquifer for a long time, making it hard to recover
Blackwater
When a build up of leaf litter and other debris is washed in to waterways during flooding, the high organic material is consumed by bacteria, depleting the dissolved oxygen in the water
This leads to the death of aquatic organisms, vulnerable to the oxygen deprivation
Despite this, it also comes with benefits. the floods that causes blackwater is essential for the river's long-term health. The organic matter that is broken down by the event also helps to supply nutrients to the overall wetland system. Other organisms benefits from this because it boosts food supplies and supports their breeding cycles.
The chemicals released from this also makes the water more alkaline or acidic, disrupting the pH balance