There are several ways to filter river water to make it safe to drink. Here are a few methods you can try:

• Boiling: Boiling is a simple and effective way to kill pathogens and make water safe to drink. Bring the water to a rolling boil for at least one minute, then let it cool before drinking.

• Chemical treatment: Chlorine tablets, iodine tablets, and water purification drops are all effective at killing bacteria and viruses in water. Follow the instructions on the package for how much to use and how long to wait before the water is safe to drink.

• Filtering: Filtering water with a physical filter can remove particles, such as dirt and sediment, as well as certain microorganisms. There are many types of water filters available, including straw filters, pump filters, and gravity filters.

• UV treatment: UV water purifiers use UV light to kill bacteria, viruses, and other pathogens in water. These systems are portable and easy to use, making them a good option for purifying water while traveling.

It’s important to note that these methods may not be effective at removing all contaminants from water. If you are in an area with contaminated water or are unsure of the quality of the water, it’s best to use a combination of these methods or to seek other sources of safe drinking water.