Effect of calcium-binding compounds in acid whey on calcium removal during electrodialysis
2022
Nielsen, Emilie N. | Skibsted, Leif H. | Yazdi, Saeed R. | Merkel, Arthur | Ahrné, Lilia M.
Electrodialysis (ED) is an efficient technology to recover calcium from acid whey (AW). The effects of calcium-binding compounds on demineralization and calcium recovery were studied during the ED process, using model solutions imitating AW. The presence of calcium-binding compounds with a higher association constant significantly decreases the extent of the removal of calcium. Lactate, present in high concentrations in AW, has a larger impact than citrate, on removing calcium during ED, although citrate has a higher affinity for calcium-binding. The largest impact of pH was observed for citrate, and at pH of AW, less calcium is bound. Sugars were found to have minor effects, but an additive effect is observed when several calcium-binding compounds are present. Measurement of bound and ionic calcium showed that calcium dissociates during ED reestablishing chemical equilibria except for citrate, which at pH of AW forms the uncharged complex CaHCitr not being transported during ED.
显示更多 [+] 显示较少 [-]