Alkalinity

ALKALINITY

• Alkalinity may be defined as the quantity of ions in water that will react to neutralise the hydrogen (H+) ions
• It represents the ability of water to neutralise acid
• Alkalinity is caused by the presence of bicarbonates of calcium and magnesium or by carbonates and hydroxides of sodium, potassium, magnesium and calcium
• Alkalinity caused by bicarbonates is called bicarbonate alkalinity
• Alkalinity caused by carbonates is called carbonate alkalinity
• Alkalinity caused by hydroxides is called hydroxide alkalinity or caustic alkalinity
• Some compounds (not all) that cause alkalinity also cause hardness
• Total alkalinity in water consists of alkalinity due to bicarbonates (HCO3-), carbonates (CO32-) and hydroxides (OH-)
• Very little negative alkalinity is also caused by H+