Water 14 Purification 13 Water quality 4 Coagulation 3 Filtration 3 Analysis 1 Lime-soda ash process 1 lisää ... Reverse osmosis process 1 Sedimentation basins 1 Settling basins 1 Slow sand filtration 1 Softening 1 Softening of water 1 methods 1 vähemmän ...