The apparent heat capacity and enthalpy of lake Urmia brine in different temperatures by using Pitzer equations

Lake Urmia (or Orm iyeh) is one of the largest hypersaline lakes in the world. Urmia Lake, located in northwestern Iran, with a total surface area between ۴۷۵۰ and ۶۱۰۰ km۲ and a maximu m depth of ۱۶ m at an altitude of ۱۲۵۰ m. The main cations in the lake water include Na+, K+, Ca+۲, Li+ a nd Mg+۲, while Cl-, SO۴ -۲, HCO۳ - are the main anions. The Na+ and C l-concentration is roughly ۴ times the concentration of natural seaw ater. Sodium ions are at slightly higher concentration in the south compared to the north of the lake, which could result from the shallower depth in the south, and a higher net evaporation rate.The thermochemical properties (osmotic c oefficient, enthalpy and heat capacity) of saline water from ۵ to ۳۵°c have been calculated by Pitzer equations. In earlier studies, the thermochemical properties of saline water have beenexamined using an extended Debye– Huckel equation, which was an extension of the equation as formulated by Lewis and Randall. More recently, the PVT properties have been calculated byPitzer equations. In thispaper, we have calculated the thermochemical properties ofurmia lake (heat capacity, enthalpy) to these equations.

کلیدواژه ها:

Enthalpy ، Heat capa city ، Pitzer equations ، U rmia brine