Evaluation of energy consumption during the seawater desalination process simulated to the aqueous ternary system {NaCl + KCl}(aq)

Energy consumption is a purely thermodynamic concept very useful in several scientific fields such as desalination, oceanography, biology, geochemistry and environmental processes, as well as in industrial applications. In this investigation, based on a thermodynamic approach, the calculation of energy consumption was evaluated during the desalination of seawater simulated to the aqueous ternary system {NaCl + KCl}(aq). The mixing ionic parameters, obtained in our previous work, are used to predict the osmotic and activity coefficients in the aqueous solutions at different salinities ranging from 3.6 up to 72 g.L-1 at T = 298.15 K using the ion interaction model. The theoretical energy consumption of desalination was calculated at various salinities and recovery ratios.

Simulation and Prediction of Solubility for the Quaternary System Containing Lithium, Sodium, Magnesium and Chloride at 273.15 K

Solubilities of the quaternary system containing lithium, sodium, magnesium and chloride at 273.15 K were calculated using Pitzer ion-interaction model and its extended HW model. The values of the Pitzer single-salt parameters β(0), β(1), β(2) and Cφ for LiCl, NaCl, and MgCl2, the mixed ion-interaction parameters θLi,Mg, θLi,Na, θNa,Mg, ψLi,Mg,Cl, ψLi,Na,Cl and ψNa,Mg,Cl, and the Debye–Hückel parameter Aφ in the quaternary system at 273.15K were derived. Based on the Jänecke indexes, the phase diagram was plotted. This study affords the necessary parameters for solubility predictions of complicated systems and establishes a theoretical basis for the separation of these valuable minerals from salt lake brine.

Solubility Prediction for the Reciprocal Quaternary System (Li+, Mg2+//Cl-, SO42-–H2O) at 273.15 K Using Pitzer Ion-Interaction Model

Solubilities of the reciprocal quaternary system (Li+, Mg2+//Cl-, SO42-–H2O) at 273.15K were calculated using Pitzer and its extended HW model. The values of the Pitzer single-salt parameters β(0), β(1), β(2)and Cφfor LiCl, MgCl2, Li2SO4, and MgSO4, the mixed ion-interaction parameters θLi,Mg, θCl,SO4, ψLi,Mg,Cl, ψLi,Mg,SO4, ψLi,Cl,SO4and ψMg,Cl,SO4, and the Debye–Hückel parameter Aφin the system at 273.15K were derived either temperature-dependent equation or through fitting solubility data of the ternary system by multiple linear regression method. Based on the Jänecke indexes, the phase diagram was plotted. This study affords the necessary parameters for solubility predictions of complicated systems and establishes a theoretical basis for the separation of these valuable minerals from salt lake brine.