water could be separated from dissolved ionic compounds by simple distillation... if there were dissolved gas or liquid portions, these should be removed prior to the distillation process if possible...pure substances have unique boiling points, and if the bp of the gas or liquid is less than water it can be separated by boiling in a container open to the atmosphere first...

I've been playing with very small scale solar distillation units for the last couple of summers (yields less than 300ml a day)... from my limited attempts, the best collector is of the "water cone" variety, where a very steep elevated center cone of the glazing material ( transparent/translucent plastic sheeting)causes an immediate run off of the condensed liquid... a circumferential collecting trough probably will work best for a large scale unit...my best attempt utilized a hanging non potable reservoir with fill tube... a dark wicking cloth draped over an elevated center to increase the evaporative surface... standoff ring circling edge of reservoir to hold an exterior translucent trash bag away... open bag is tied shut at vertex of the hanging reservoirs support arms, and weighted at corners of bag to hold in position... water condenses and runs to the weighted corners..