The goal of the study was to find the best way to remove trace phosphorus from drinking water. The researchers tested different coagulants and found that ferric trichloride and poly ferric sulfate worked the best. By using these coagulants at a dosage of 15mg/L and adjusting the pH value and temperature, the concentration of phosphorus in drinking water could be reduced to safe levels. They also discovered that sulfate and chloride ions had little impact on phosphorus removal, while carbonate ions had some influence. Overall, using ferric trichloride and poly ferric sulfate can effectively remove phosphorus from drinking water and meet the standards for safe drinking water.