The researchers tested a high-speed filter made of special fibers to clean very dirty water quickly. They found that adding a certain chemical helped the filter work better. Even when the water was very dirty, the filter still removed a lot of dirt. The faster the water flowed through the filter, the less effective it was, but it still worked well at high speeds. The size of the dirt particles in the water didn't make a big difference. The researchers came up with a new way to predict how well the filter would work, which could be useful for future water treatment.