Water purification methods include sedimentation, filtration, aeration, chlorination, distillation, and reverse osmosis. Sedimentation involves allowing impurities to settle in tanks, and filtration passes water through layers of sand, gravel, and other materials. Aeration uses pressurized air to kill bacteria, and chlorination adds chemicals to kill remaining microbes. Distillation heats water to vapor and then cools the vapor to liquid, leaving impurities behind. Reverse osmosis uses a semipermeable membrane to retain solutes on one side while allowing solvent like water to pass through.