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Lime softening (also known as lime buttering, lime-soda treatment, or Clark's process) [1] is a type of water treatment used for water softening, which uses the addition of limewater (calcium hydroxide) to remove hardness (deposits of calcium and magnesium salts) by precipitation.
Large cation/anion ion exchangers used in water purification of boiler feedwater [4] Ion exchange can also be used to remove hardness from water by exchanging calcium and magnesium ions for sodium ions in an ion-exchange column. Liquid-phase (aqueous) ion-exchange desalination has been demonstrated. [5]
Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which "hardness ions"—mainly Ca 2+ and Mg 2+ —are exchanged for sodium ions. [7] As described by NSF/ANSI Standard 44 , [ 8 ] ion-exchange devices reduce the hardness by replacing magnesium and calcium (Mg 2+ and Ca 2+ ) with sodium or ...
Like water softeners, dealkalizers contain ion-exchange resins that are regenerated with a concentrated salt solution - NaCl. In the case of a water softener, the cation exchange resin is exchanging sodium (the Na + ion of NaCl) for hardness minerals such as calcium and magnesium. A dealkalizer contains strong base anion exchange resin that ...
The synthesis of aspirin is classified as an esterification reaction. Salicylic acid is treated with acetic anhydride, an acid derivative, causing a chemical reaction that turns salicylic acid's hydroxyl group into an ester group (R-OH → R-OCOCH 3). This process yields aspirin and acetic acid, which is considered a byproduct of this reaction.
where R is the gas constant (8.314 J mol −1 K −1), T the temperature (K), Φ v,fresh, the flow rate of the fresh water outflow (m 3 /s), C feed the concentration of ions in the feed water (mol/m 3) and C fresh the ion concentration in the fresh water outflow (mol/m 3) of the CDI cell.
Low-mineral water has been implicated in specific cases of lead poisoning in infants, when lead from pipes leached at especially high rates into the water. Recommendations for magnesium have been put at a minimum of 10 mg/L with 20–30 mg/L optimum; for calcium a 20 mg/L minimum and a 40–80 mg/L optimum, and a total water hardness (adding ...
This might include pure chemical synthesis or boiler feed water. Also, some water treatment processes produce organic and mineral sludges from filtration and sedimentation which require treatment. Ion exchange using natural or synthetic resins removes calcium, magnesium and carbonate ions from water, typically replacing them with sodium ...