Introduction to Environmental Studies: Water Pollution

Comprehensive vocabulary flashcards covering the key terms, pollutant types, sources, health and environmental effects, and control measures of water pollution from the Environmental Studies lecture.

Water Pollution

Undesirable changes in the physical, chemical, or biological properties of water that render it unfit for use by humans and other living organisms.

Universal Solvent

A characteristic property of water that makes it uniquely vulnerable to pollution, allowing toxic substances from farms, towns, and factories to readily dissolve and mix with it.

Organic Pollutants

Water contaminants primarily derived from living organisms or synthetic production, including faecal matter, decaying plants and animals, sewage, synthetic organic chemicals, microbiological agents, and oils.

Synthetic Organic Chemicals (SOCs)

Artificially manufactured organic water contaminants, including pesticides, herbicides, dioxins, and polychlorinated biphenyls.

Inorganic Pollutants

Water pollutants originating from natural mineral sources such as rocks as well as industries, including mineral acids, bases, salts ($SO_4$, $NO_3$, $PO_4$, cyanides, fluorides, chlorides), and heavy metals ($Pb$, $Cr$, $Cd$, $Hg$, $As$).

Radioactive Pollutants

Pollutants such as uranium and thorium that enter water from natural mineral sources like rocks or man-made sources including nuclear waste and weaponry.

Suspended Solids and Sediments

Insoluble impurities such as soil, sand, and other solid particles that either stay suspended in water bodies or settle out at the bottom as sediments.

Thermal Pollution

The discharge of heated effluent water from thermal power plants and industrial installations into water bodies, raising water temperatures and lowering dissolved oxygen ($DO$) levels.

Point Sources

Sources of water pollution whose discharge location can be pinpointed to a single identifiable point, such as municipal sewage discharge pipes and industrial effluent outlets.

Non-point Sources

Diffused or area-wide sources of water pollution that are scattered over large expanses and cannot be traced to a single location, such as agricultural and forest runoff.

Physical Effects of Water Pollution

Direct changes to water quality characteristics including elevated temperature, higher turbidity, changed conductivity, dissolved oxygen ($DO$) depletion, altered colour, and surface oil films that reduce photosynthesis and kill aquatic life.

Oxidation Effects of Water Pollution

Biological and chemical oxidation processes in polluted water where impurities consume dissolved oxygen as they oxidize, such as converting sulphides into sulphates and ammonia into nitrites and nitrates.

Minamata Disease

A severe neurological syndrome caused by mercury ($Hg$) poisoning, characterized by ataxia, numbness in the hands and feet, muscle weakness, visual field constriction, and impairment of hearing and speech.

Itai-Itai Disease

A painful illness caused by chronic cadmium ($Cd$) poisoning, characterized by osteomalacia, severe bone pain, and renal dysfunction.

Black Foot Disease

A peripheral vascular disease caused by exposure to water contaminated with arsenic ($As$).

Eutrophication

The nutrient enrichment of a water body by agricultural runoff containing nitrates and phosphates, triggering excessive growth of water weeds and algae blooms, resulting in oxygen depletion and fish kills.

Methemoglobinemia

A serious condition (referred to in the notes as 'metheamoglobin') resulting from agricultural fertilizers such as nitrates and phosphates leaching into rivers, ponds, and drinking water sources.

Biological Magnification

The progressive accumulation and increasing concentration of persistent toxic chemicals (such as DDT and aldrin) in organisms at sequentially higher trophic levels in a food chain.

Gambusia Fish

A specialized breed of fish intentionally cultured in water bodies as a biological control measure to consume mosquito eggs and bacteria.

STPs and ETPs

Sewage Treatment Plants and Effluent Treatment Plants; specialized facilities required to treat domestic wastewater and industrial effluents before they are released into aquatic bodies.