The study looked at how adding certain chemicals can help keep a filter from getting clogged. By using coagulation, the researchers found that the filter's flow rate could be fully restored after cleaning, while without coagulation, the flow rate was only 40% of the original. The type of layer that forms on the filter during use determines whether coagulation helps prevent clogging. When coagulation is used, a layer forms that stops clogging, but without it, clogging occurs due to small, neutral, water-loving compounds that can't be removed easily.