Depends what your impurities are. If you have a lot of other liquids mixed in (oil , organic solvents etc) then distillation can be easier - it also lets you se

Depends what your impurities are. If you have a lot of other liquids mixed in (oil , organic solvents etc) then distillation can be easier - it also lets you separate them for disposal. Small scale pure 'distilled' water eg. for battery top-up, is typically made by ion-exchange resin - it's more effective than osmosis for removing very small amounts of inorganics and cheaper than actual distilling if you are starting with fresh water.