The study looked at how polluted the Le′an River is and found that the main pollutants come from things like farming, livestock, and wastewater from towns. Specifically, the main pollutants are substances called COD_Cr and NH_3-N. To fix this, they suggest cleaning up the water to meet certain standards, building treatment plants for the dirty water, stopping pollution from things like farms, bringing back the natural balance in the area, and keeping a closer eye on what's going on in the river.