Acidity is a measure of a solution’s capacity to react with a strong base (ex. NaOH) to a predetermined pH value. Acidity levels are measured in wastewater because it can be responsible for corrosive properties and can take a leading role in regulating biological processes as well as in chemical reactions.
Alkalinity is a measure of the acid-neutralizing capacity of water and is measured by titrating the solution with an acid (ex. H2SO4) until it reaches a known endpoint wherein its pH changes abruptly. Alkalinity of wastewater is measured as it affects biological processes and chemical reactions.
Turbidity is the cloudiness or haziness of a fluid which is a measure of water quality. It is a reduction in water clarity/transparency due to the presence of suspended particulates. This is usually measured to determine the optical property of solutions as it causes light to be scattered and absorbed rather than transmitted in straight lines through a sample.
Water hardness is the sum of the calcium and magnesium concentrations in the water. Hard water is high in dissolved minerals, largely calcium and magnesium. Water hardness is expressed as mg/L hardness as calcium carbonate. It is usually measured in industries because water hardness affects chemical reactions, industrial processes, and health considerations (for drinking water).