Water chemistry
Water chemistry studies water’s chemical properties and the dissolved substances, reactions, and equilibria that shape natural and engineered waters.
pH: A logarithmic measure of hydrogen-ion activity in a solution. It summarizes acidity, which controls many reactions and dissolved forms in water.
Chemical speciation: The distribution of an element among its distinct chemical forms in a system. A total concentration alone cannot show which dissolved form is present or reactive.
Drinking water quality: The chemical, physical, and microbiological characteristics that determine whether water is suitable to drink. Chemical measurements help identify treatment needs and assess compliance with standards.
Eutrophication: Nutrient enrichment of water that can drive excessive algal growth and oxygen depletion. Nitrogen and phosphorus concentrations help determine whether enrichment occurs.
Hydrology: The science of water’s occurrence, movement, and distribution on Earth. Hydrology tracks where water goes; water chemistry examines its dissolved composition and reactions.
Alkalinity: A measure of water’s capacity to neutralize added acid, mainly through bicarbonate and carbonate. It describes resistance to pH change in natural and treated waters.
Carbonate system: The linked dissolved forms of carbon dioxide, carbonic acid, bicarbonate, and carbonate in water. Its equilibria connect pH, alkalinity, and dissolved inorganic carbon.
Wastewater treatment: Processes that remove contaminants from used water before discharge or reuse. Chemical reactions and equilibria underpin nutrient removal, disinfection, and solids control.
Ocean acidification: The long-term decrease in ocean pH caused mainly by uptake of atmospheric carbon dioxide. It is a large-scale consequence of carbon dioxide dissolving and reacting in water.
Analytical chemistry: The branch of chemistry concerned with identifying and measuring substances. It provides measurement methods, while water chemistry applies them to aqueous systems.