Yr7 Enough Water Fit for Drinking

Rebuttal

A statement disproving another in an argument. Rebuttals should be supported by evidence and reasoning.

Argument

A statement of reason/s supporting an opinion. An argument should include claims and evidence.

Claim

A statement said to be true. Claims should be supported with evidence as part of an argument.

Iron

A type of metal. Particles of iron can affect the taste and appearance of water.

Catchment

An area of land that collects rainfall and contributes to surface water (streams, rivers, wetlands) or to groundwater.

Drought

An extended period of less than average precipitation.

Particle

An individual piece of matter. Particles include atoms and molecules.

Impermeable

Not allowing substances including liquids and gases to pass through.

Impurity

Pollutant or contaminant in a substance.

Organic contaminant

A carbon-based chemical, such as a solvent or pesticide, which enters water through agriculture run off or factory discharge.

Disinfection

A chemical (commonly involving chlorine, chloramines, or ozone) or physical process (e.g. ultraviolet light) that kills microorganisms such as viruses, bacteria and protozoa.

Pollutant

A contaminant at a concentration high enough to endanger the lives of living things.

Pathogen

A disease-producing microorganism.

Attraction

A force between two objects drawing them together.

Sand filtration

A frequently used method to remove suspended solids from water. The water is passed through multiple layers of sand with a variety in size and specific gravity.

Water recycling

A generic term for water reclamation and reuse.

Microorganism

A living thing so small it can only be observed through a microscope, for instance bacteria, fungi or yeasts. Some microorganisms can cause extreme health problems when consumed in drinking water.

Alkalinity

A measure of how basic a substance is. Alkalinity is the opposite of acidity.

pH

A measure of how basic or acidic a substance is.

Turbidity

A measure of how cloudy a liquid looks because of solid particles suspended in it.

Acidity

A measure of how corrosive a substance is. Acidity is opposite to alkalinity.

Solubility

A measure of the amount of a substance that will dissolve in a unit volume of water.

Semi-permeable

A medium that allows some substances to pass through, but rejects others based on their properties. A semi-permeable material can be used to separate solids from water.

Capillary membrane

A membrane about the thickness of a human hair, used for reverse osmosis, nanofiltration, ultrafiltration and microfiltration.

Atom

A microscopic piece of matter. Different types of atoms have different properties. Atoms can be joined to similar or different atoms through chemical bonds, forming molecules.

Inorganic contaminant

A mineral-based compound such as a metal or nitrate that occurs naturally in some water, but can also enter the water through human activities.

Suspension

A mixture in which solid particles are not dissolved and do not immediately sink within the liquid. If left to stand, the particles would sink to the bottom and form a layer of sediment.

Non-solution

A mixture in which substances are not dissolved. Non-solutions include suspensions and colloids.

Mixture

A mixture is a combination of two or more different materials. They are not chemically bonded. A mixture can usually be easily separated back into its original components.

Solution

A mixture that contains one or more substances (the solute) dissolved in another (the solvent).

Molecule

A molecule is two or more atoms held together by chemical bonds. It may contain atoms from the same element or a variety of elements.

Filtration

A process in which particulate matter in a liquid is removed by passing it through porous material.

Flocculation

A process in which small particles clump together through gentle stirring.

Positive and negative charge

A property of an object causing an attraction or repulsion of other charged objects.

Fair test

A scientific investigation in which one variable is changed, one is measured or observed and all other variables are kept the same.

Water quality analysis

A series of tests to determine various chemical or physical characteristics of a sample of water.

Dissolved solid

A solid material that is totally dissolved in water and cannot be removed by means of filtration.

Bond

A strong attractive force holding atoms or molecules together.

Solvent

A substance (usually liquid) capable of dissolving one or more other substances.

Nitrate

A substance containing nitrogen and oxygen. Nitrates can cause sickness in people and can also contribute to algal blooms in waterways.

Colloid

A substance made up of particles that are relatively large. These particles are larger than those in a solution but are small enough to stay suspended in another substance.

Compound

A substance that contains at least two elements. Atoms of these elements are held together in fixed ratios by chemical bonds. Compounds have different properties to those of the individual elements.

Algal bloom

A sudden increase in the number of bacteria in a waterway. Algal blooms can release toxins that can cause sickness if consumed.

Water source

A supply or store of water. Water sources include rivers, bores and desalination of ocean water.

Micro filter

A system for separating substances from water involving a semipermeable material with very small pores.

Membrane

A thin barrier that allows some materials to pass through and traps others. It is a semi-permeable skin—some particles can pass through depending on their size or other properties. Membranes are commonly used to separate substances.

Pore

A tiny hole or opening in a substance, allowing some materials to pass through it.

Substance

A type of matter.

Copper

A type of metal. Particles of copper can dissolve in water and cause sickness in people if consumed.

Distillation

A water treatment method where water is boiled and then condensed in a separate reservoir. Contaminants with higher boiling points than water do not vaporise and remain in the boiling flask.

Hydrogen bond

A weak attraction between hydrogen and fluorine, oxygen or nitrogen. Hydrogen bonds form between the hydrogen and oxygen atoms in separate water molecules.

Permeable

Able to pass a fluid under pressure.

Reverse osmosis

An advanced method of waste water treatment that works by forcing water molecules through a semi-permeable membrane to separate it from impurities.

Aquifer

An underground layer of permeable rock, sand or gravel that holds water. Water found within an aquifer is called groundwater.

Reservoir

Any natural or artificial holding area used to store, regulate or control water.

Contaminant

Anything found in water (including microorganisms, chemicals, minerals etc) that may be harmful to human health.

Evidence

Data used to prove or disprove a statement. Scientific evidence includes measurements and observations.

Polar

Describing a molecule which has a slight positive charge at one end and a slight negative charge elsewhere.

Non-polar

Describing a molecule which has an even charge all over it.

Grey water

Domestic wastewater composed of wash water from kitchen, bathroom, and laundry sinks and from tubs, and washing machines.

Data

Information such as observations and measurements.

Vox pop

Looking at the opinion or ideas of everyday people. Vox pop interviews are often conducted with people approached on the street.

Source control

Managing potential pollution before it reaches the water storage. This includes reducing the use of harmful chemicals that can be flushed into the sewerage.

Sewage

Material from internal household and other building drains. It includes faecal waste and urine from toilets; shower and bath water; laundry water and kitchen water. Sewage can be treated and the water returned to the environment.

Solute

Matter dissolved in a liquid, such as water.

Radiological

Relating to nuclear radiation.

Microbiological

Relating to small living things that can only be seen using a microscope.

Sediment

Soil, sand, and minerals washed from land into water, usually after rain. When these particles settle to the bottom of a water body this is called sedimentation.

Aquatic ecologist

Studies the relationships among aquatic living things and between those organisms and their environment.

Cohesion

The attraction between particles of a substance. Some substances are more cohesive than others.

Adhesion

The attraction between particles of one substance and another. The strength of the attraction depends on the properties of each of the substances.

Condensation

The change of state from a gas to a liquid.

Stormwater harvesting

The collection and use of stormwater for irrigation of vegetation such as ovals and gardens.

Indirect potable reuse

The discharge of recycled water into surface water or groundwater (called managed aquifer recharge). The recycled water is mixed with the rest of the water in the source rather than being used directly from the treatment plant.

Separation

The isolation of the various compounds in a mixture.

Water cycle

The process by which water moves through the environment. It includes evaporation, condensation, precipitation and runoff. It is also called the hydrologic cycle.

Dissolving

The process during which a solid mixes molecule by molecule with a liquid and appears to become part of the liquid.

Settling

The process of a substance sinking in water. This occurs when the substance does not dissolve in water and its density is higher than that of water. Material that has settled can easily be removed from water.

Evaporation

The process of changing from a liquid to a vapour.

Osmosis

The process of water molecules passing through a membrane towards the side with the highest concentration of dissolved impurities.

Coagulation

The process through which fine particles are clumped together. Chemicals are often added to neutralise the charge on the particles. The resulting mass can be easily removed.

Physical and chemical treatment of water

The processes generally used in wastewater treatment facilities. Physical processes include filtration. Chemical treatment includes coagulation, chlorination, or ozone treatment.

Health qualities of water

The properties of water that affect human health.

Flux

The rate at which a reverse osmosis membrane allows water to pass through it.

Desalination

The removal of salt from seawater or brackish water to produce drinking water. Modern desalination plants use a process called reverse osmosis. Desalinated water is often used to supplement drinking water supplies in many countries, including some Australian cities and towns.

Primary wastewater treatment

The removal of suspended, floating and precipitated solids from untreated wastewater.

Surface tension

The tendency of a liquid to minimise its surface area. Surface tension is related to cohesion and is sometimes described as being like a 'skin' on the surface.

Sewerage

The underground drainage system that transfers the sewage mixture to treatment plants.

Screening

The use of screens to remove coarse floating and suspended solids from sewage.

Submicroscopic

Too small to see directly through a microscope. For example, all matter is made up of submicroscopic atoms.

Multiple barriers

Using different types of water purification processes to increase the effectiveness of the treatment.

Recycled water

Water that has been reclaimed from sewage, grey water or stormwater systems and treated to a standard that is appropriate for its intended use.

Groundwater

Water contained in underground stores (aquifers) that can be accessed through a bore.

Urban runoff

Water from city streets and domestic properties that carry pollutants into the sewer systems and receiving waters.

Source water

Water in its natural state, before any treatment to make it suitable for drinking.

Potable water

Water intended for human consumption—suitable on the basis of both health and aesthetic considerations for drinking or culinary purposes.

Surface water

Water that comes from rainfall and its runoff into streams and rivers. Surface water can come from a river, lake or artificial dam.

Safe water

Water that does not contain harmful bacteria, toxic materials, or chemicals, and is considered safe for drinking.

Waste water

Water that has been used and contaminated. This includes water that is flushed down the toilet, emptied from the sink or used in manufacturing.

Stormwater

Water that washes across roads and streets, picking up oil, petrol, grease, sediment, industrial waste, leaf and other litter and dog droppings on roads, streets and paths.

Purified water

Water without any contaminants. The highest grade of water, even purer than potable water, can be produced using technologies of microfiltration, reverse osmosis and ultraviolet light. It can be used for kidney dialysis and industrial processes such as pharmaceuticals or boiler feed water.