Spiral Wound Electrodialysis Module

A spiral-wound electrodialysis module includes an inner electrode positioned about a central axis and an outer electrode surrounding the inner electrode. Ion exchange membranes are arranged in a stack, and each membrane extends in a spiral outward from an inner position proximate the inner electrode to an outer position proximate the outer electrode. The spirals expand outward at a greater-than-linear rate as a function of angle along a length of the spiral from the inner positions to the outer positions.