Final answer:
Removing temporary hardness in water can be achieved through methods like lime softening, ion exchange, chelation, and the use of commercial water softeners.
Step-by-step explanation:
To remove temporary hardness in water, various methods can be used such as lime softening, ion exchange, chelation, and the use of commercial water softeners. Lime softening involves adding calcium hydroxide (Ca(OH)2) to the water to precipitate calcium and magnesium into insoluble compounds that can be filtered out. Ion exchange softeners replace hard ions like Ca2+ with more acceptable ones like Na+ by running water through a resin-containing column.
Chelation uses agents like EDTA to bind and remove hard water ions, thus mitigating their interaction with soap and other substances. Finally, commercial water softeners often incorporate complexing agents using ion-exchange resins to exchange hard water ions with sodium ions, although this may impart a saltier taste to the water.