Experimental investigation into the transmembrane electrical potential of the forward osmosis membrane process in electrolyte solutions

Lixia Bian; Yanyan Fang; Xiaolin Wang

doi:10.3390/membranes4020275

Experimental investigation into the transmembrane electrical potential of the forward osmosis membrane process in electrolyte solutions

Membranes (Basel). 2014 Jun 19;4(2):275-86. doi: 10.3390/membranes4020275.

Authors

Lixia Bian¹, Yanyan Fang², Xiaolin Wang³

Affiliations

¹ Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. blx11@mails.tsinghua.edu.cn.
² Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. fyy04@mails.tsinghua.edu.cn.
³ Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. xl-wang@tsinghua.edu.cn.

Abstract

The transmembrane electrical potential (TMEP) in a forward osmosis membrane process with a single electrolyte solution as the draw and feed solutions was investigated by experiments. The effects of membrane orientation, the electrolyte species (KCl, NaCl, MgCl2, and CaCl2), concentration and concentration ratio of solutions at both sides of membrane on water flux and TMEP were investigated. The results showed that the TMEPs at different membrane orientation cannot completely coincide, which confirmed the effect of membrane asymmetry. The ion diffusion coefficients significantly affected the TMEP across the membrane, with different patterns for different electrolytes and concentrations.