Water consumption, liquid effluents and conservation Flashcards
Describe the natural and urban water cycle
The water cycle is continuing process of evaporation, condensation, transpiration and precipitation through interconnecting processes. Water is abstracted in bulk from natural environmental sources such as surface waters (rivers, lakes, seas) and ground water, and distributed to businesses and residences through mains supply. Once water has been used, it is recycled through sewer pipes and wastewater treatment before discharge back to the environment.
Water is distributed around the globe by evaporation of water into the atmosphere, which is then moved by clouds as released as rain or storm water in a different location - whether it be mountains, flat land, or directly back to a water source such as a reservoir.
In the urban water cycle, infiltration and run-off must also be considered.
Draw the water cycle
Drawing 2
What helps distribute water between the equator and the poles?
Precipitation growing into large storms and migrating across the atmosphere
How storms grow and intensify depends on what?
Atmospheric moisture, surface temperatures and wind patterns
How is rainfall stored on land?
Snow, reservoirs, lakes, soils and underground aquifers
How does water availability affect food?
It affects the types and amounts of food that can be grown
How does water from mountains return to rivers etc.?
Through run off, percolation and then transport through the ground. Some is taken up by plants or evaporates.
Draw the water paradigm
Drawing 1
What affects what pollutants we see in wastewater?
How we use it
What kind of pollutants would we expect to see from agriculture?
Nutrients
What is tidal water mostly used for?
Electricity (the biggest consumer of water in the UK)
Why does electricity supply need lots of water?
- To work turbines
- Cooling
How much water do you use per day to stay alive?
7.5-15 L/day
In what activities do you produce wastewater?
Washing, toilet flushing, cooking
How many litres of water is used to flush a toilet?
Around 5-10 litres
In what domestic activities do you produce wastewater (from most to least)?
Toilet flushing (33%), bath&shower (32%), cleaning (20%), car&garden (13%), drinking water (2%)
How many litres of water is used to flush a toilet?
Around 5-10 litres
13 for an old style toilet
What is the total water footprint per person per day? (not provided on equation sheet)
Around 150 L/person/day for a family of 3
Around 165 L/person/day for a single person
How much organic matter is produces per person per day?
60g
How much water does an average washing machine use?
50L
How many toilets are there in the UK and how much water do these use everyday?
45 million, 2 billion L freshwater/day
What is virtual water?
Water that has been used for the entire process of producing a product
How much embedded water is there in a cup of coffee?
140 L
How much embedded water is there in a glass of milk?
255 L
How much embedded water is there in a pizza and beer?
1259 and 74 L
How much embedded water is there in tomato puree?
710L/kg
How do water footprints vary from country to country?
France
How much embedded water does one person actually use per day?
4645 L (about 75 washing machines runs)
How much embedded water is there in agriculture products?
3400 L/person/day (out of this cotton is 211)
How much embedded water is there in industrial products?
1095 L/person/day
Give 5 examples of high industries that use high amounts of water in order of most to least (exam q)
- Electricity generation
- Iron and steel industry
- Mines and quarries
- Food industry
- Brewing
- Nuclear
- Agriculture
- Water treatment
How much of water from brewing ends up as an effluent and what kind of pollutants are you likely to see?
> 70%, yeast, N and P
Define water pollution
Any physical, biological, or chemical change in water quality that adversly affects living organisms or makes water unsuitable for desired usage
What are the two types of sources of pollution?
Point source - pollution from specific locations
Non-point sources - scattered or diffuse, having no specific location of discharge
Give 4 examples of point source pollution and what they contain
- Industry (organics (microorganisms consume oxygen to break these down resulting in dead environments), inorganics, metlas, colour and foam, salts, toxins, heated water
- Power plants (heated water)
- Feedlots (organics, solid, nutrients (NO3 and PO4, microorganisms)
- Municipalities (urban and industrial wastewaters) (microorganisms, organics, colour and foam, nutrients and hormones)
Give 3 examples of non-point source pollution and what they contain
- Agricultural land drainage (silt from erosion, fertilisers, pesticides (stay around for a long time) organics, microorganisms)
- Mining (suspended solids, acid mine drainage spreads for a long time and can change ecology)
- Urban storm runoff (dust, dirt, and litter, metals, salt especially due to snow in winter, oil&grease, fertiliser, pesticides, nutrients)
How much of all pollution is non-point source?
90%
In what 3 forms does water pollution come in?
Physical, chemical and biological
What industry uses the most non-tidal water sources?
Equal between electricity and public water supply
How do pollutants affect the environment?
- Can be volatised into the atmosphere (ammonia)
- Low water solubility causing sediment
- Ingestion
- Oxygen demanding
What does pollutant affect on the environment impact?
- The environment
- Resources are wasted (heavy metals, nutrients, energy)
- Economy (profitability)
- Social (closure of waterways)
What is the size of our global eutrophication problem?
30-40% of lakes and rivers impacted, >400 coastal dead zones (10% increase per decade), in England 77% of surface water is eutrophic
Draw a eutrophication diagram
Drawing 3
What is the tipping point of eutrophication?
The point at which the environment cannot be recovered from the effects of excess nutrients
Describe the 5 events in the chain of eutrophication
- N and P promote excessive growth of aglae and cyanobacteria
- Algae die due to a lack in something (usually sunlight due to overgrowth)
- Algae sink to the bas of the pond
- Dead algae is decomposed by aerobic microorganisms which depletes the DO in the water
- Fish/other life die due to lack of oxygen
How is global warming contributing to the eutrophication problem?
Increased water temperatures exacerbate the effect of excess N and P in the water
In theory, how much algae can a ton of nitrogen produce, assuming 1 mol of N produced 1 mol of algae?
9100 kg, working shown in drawing 4
Name 3 ways we reduce eutrophication happening and why is this difficult?
- Not releasing the nutrients - made worse by pressure on farmers to use more fertiliser to grow more efficiently, and use of machinery that compacts soil which increases run-off
- Mechanically removing algae before it dies
- Alum treatment
What are the 3 main sources of nutrient pollution?
Industry (washing powders), agriculture and sewage
Name 5 ways to treat a eutrophied lake
- Dredging - invasive, costly, toxicity, increases release of legacy phosphorous
- Aeration - get some oxygen back into the system
- Biomanipulation - something to eat the algae?
- Harvesting - removing the algae is very energy intensive
- Sediment treatment
Define conservation of water to reduce wastewater
By reducing the amount of wastewater entering sewers in the first place, we can reduce the amount of liquid effluent entering the environment
List 5 benefits of conservation
- Minimise the amount of water that is used, which saved costs
- Minimise the amount of water that is discharges, which saves money on treatment
- Increases water availability
- Increases environmental awareness in general
- Improves community relations
What questions can you ask to help with improving conservation in industry?
- Can the amount of water be reduced?
- Can lower quality water be used?
- Is the process/activity necessary?
- Is clean water going down the drain?
- Can water be recovered elsewhere?
Give 5 ways in which conservation has been successfully implemented in industry
- Adjust water flow
- Modify equipment/install water saving devices
- Install more water efficient equipment
- Reuse/recycle water
- Change to a low-water/waterless process
What is the most effective domestic level conservation? What are some others?
Fixing leaks (biggest issue) Clothes washing, showering, toilets (can be almost 100% more efficient)
What is a reasonable percentage of domestic water conservation with reasonable changes?
31%
Describe the principle of reusing water
By putting processes next to each other one process can utiilise the wastewater from the other process (need to evaluate quality and quantity)
Give an example where lower quality water could be used
Toilets
Which two ways do we evaluate the impact of liquid effluents from a process?
- Quantity
2. Quality
How do liquid effluents have economic effects?
Cost of cleanup
How do liquid effluents have social effects?
People being able to use the environment
How do liquid effluents have environmental effects?
Fish die
How do liquid effluents have health effects?
Toxins from cyanobacteria
Define bioaccumulation
Any kind of toxin that accumulates in animals
Define blue water footprint
The volume of surface and groundwater consumed to produce a good or carry out a service. Consumption refers to the volume of freshwater used and then evaporated or incorporated into a product. It is the amount of water abstracted from groundwater or surface water that does not return to the catchment from which it was withdrawn.
Define green water footprint
The volume of rainwater consumed during the production process. Relevant for agricultural and forestry products (products based on biomass)
Define grey water footprint
The volume of freshwater that is required to assimilate the load of pollutants based on natural background concentrations and existing ambient water quality standards. Indicator of freshwater pollution that can be associated with the production of a product over its full supply chain.
What category of wastewater does water from residences, business buildings, institutions etc. fall into?
Municipal
Define biomagnification
The increase in concentration of a toxic chemical higher up the food chain
What is the effect of biomagnification of toxins on the environment?
Aquatic diseases and deformities may be experiences when toxic liquid effluents are discharged into water bodies
Define domestic black water
The portion of the wastewater stream that originates from toilet fixtures, dishwashers and food preparation sinks
Define domestic grey water
Water captured from non-food preparation sinks, showers, baths, spa baths, clothes washing machines, and laundry tubs
Define domestic yellow water
isolated waste stream consisting of urine collected
What is acid drainage a potentially severe pollution hazard associated with?
Mining
Describe the process of acid mine drainage
Pyrite and other sulphide minerals oxidise on exposure to oxygen and water to create ferrous ions and sulphuric acid. Catalysed by bacteria, the ferrous ions react further with oxygen, producing hydrated iron oxide. This contaminates the surrounding soil, groudwater and surface water, producing water with a lower pH.
