An accurate calculation model for Na+ concentration in seawater desalination solution
- 標題
- An accurate calculation model for Na+ concentration in seawater desalination solution
- 作者
- Hongliang Qiana, Fawen Wu, Feng Zhang, Zheng Zhou, Zhibing Zhang
- 文件屬性
- 國外期刊
- 知識分類
- 礦物質分離
- 出版年
- 2013
- 刊名
- Desalination
- 關鍵字
- Seawater desalination; Ion selective electrodes; Sodium ion's concentration; Nernst equation; Pitzer equation; Activity coefficient
- 點閱數
- 2433
摘要
Based on the Nernst equation, the relationship between the electromotive force (EMF) of NaCl (denoted as Esw) and the concentration of sodium ion (denoted as c(Na+)sw) in seawater desalination solution was derived as follow: Esw=E0+Slg((γsw±NaCl)2c(Na+)swc(Cl-)sw). The value of the standard EMF (E0) and the parameter S can be obtained with the binary system of NaCl–H2O by correcting electrode. The activity coefficient of NaCl in seawater desalination solution (denoted as γsw±NaCl) was calculated by the simplified Pitzer equation, and shown good agreement with the experimental result. Through this model, the functional relationship between c(Na+)sw and Esw can be obtained once the functional relationship between γsw±NaCl and c(Na+)sw is regressed and E0, S are available. Compared with the direct potentiometry method, this model can provide wider measuring range including linear and nonlinear parts and higher accuracy whose deviation is 1.37%, as well as no need for standard buffer solution.