Only (mostly) water evaporate, salt and most contamination don't, so you get a brine that you must manage because otherwise it clog your heat exchangers and eva

Only (mostly) water evaporate, salt and most contamination don't, so you get a brine that you must manage because otherwise it clog your heat exchangers and evaporation towers. Also, it must be returner to a river carefully to not kill all fish and life forms there.