Selective precipitation of calcium ion from seawater desalination reverse osmosis brine

Towards sustainable production of minerals and chemicals through seawater brine treatment using Eutectic freeze crystallization and Electrodialysis with bipolar membranes

“…Indeed, according to projections, the desalination industry will produce approximately 54 billion m 3 of water per year by 2030 (Shahzad et al, 2017). Aside from freshwater, desalination technologies also produce a concentrated wastewater stream, known as brine (Molinari et al, 2021), which is typically disposed of using methods such as sewer discharge, deep-well injection, surface water discharge, and evaporation ponds (Panagopoulos andHaralambous, 2020a, Xevgenos et al, 2015a). However, these brines also represent an incredibly rich source of valuable elements, whose recovery could be economically viable and environmentally sustainable, as it could contribute reducing the risk of negative environmental impacts due to the disposal of such concentrated brines (Panagopoulos and Haralambous, 2020b).…”

Mining Minerals and Critical Raw Materials from Bittern: Understanding Metal Ions Fate in Saltwork Ponds

“…This could be observed when analyzing the Sr (II) on the precipitates in ponds P5-P6 with values up to 1.7 mg/kg and latter reaching values up to 3 mg/kg in the last ponds. Removal and precipitation was well described by formation of celestite, however, as described in the literature (Molinari et al, 2021), precipitation of calcite in brines is kinetically favored by the presence of Sr(II) and Mg(II). The substitution of Ca (II) cations by Sr(II) and Mg(II) ions is more favored in the aragonite crystal structure than in calcite.…”

Techno-Economic Analysis of Seawater Reverse Osmosis Brines Treatment Using Nanofiltration Modelling Tools

“…In order to recover valuable elements from SWRO brines within the Sea4Value project (http://www.sea4value.eu) [5], the solution would be pre-treated to remove Ca(II) as carbonate (i.e., aragonite or calcite) before entering the NF unit in order to avoid scaling [6]. Molinari et al [6] evaluated the Ca(II) removal from SWRO brines using different alkaline agents (Na 2 CO 3 , NaHCO 3 ). Authors reported that it would be possible to remove 90 % of Ca(II) as carbonate working at 60 • C and a stoichiometric excess of 10 % of NaHCO 3 .…”

“…Sea4Value research project) requires the design, development and implementation of a multi-mineral and modular process integrating novel and advanced separation technologies, reaching an innovative brine mining method [5]. The global recovery scheme could be divided into three main stages: i) reverse osmosis (RO) brines pre-treatment for calcium removal to avoid fouling events in the following processing steps [6] and fractionation of target monovalent and multivalent ions into two streams, ii) concentration of both streams and iii) final selective recovery of the target minerals by integration of purification steps incorporating precipitation and crystallization processes [7]. In recent years, nanofiltration (NF) has been used to treat different kinds of water and wastewater [8], such as municipal wastewater [9], brackish water in irrigation [10] or industrial brines [11].…”