Dissolved Load: What Rivers Carry in Solution

Chemical Cargo of Flowing Water

Dissolved load (solute load) is the material transported in true chemical solution. It includes:

• Major Ions: Bicarbonate, calcium, magnesium, sodium, potassium, sulfate, chloride, nitrate.
• Nutrients: Nitrogen, phosphorus, potassium (from agriculture, sewage, decay).
• Organic Compounds: Humic substances, tannins, lignins from decomposing vegetation.
• Inorganic Pollutants: Heavy metals, pesticides, industrial chemicals.
• Dissolved Gases: O₂, CO₂, CH₄ from atmosphere and biological processes.

Measurement & Impact

Concentration expressed in ppm or mg/L (Total Dissolved Solids). High TDS affects taste, health, irrigation suitability. Nutrients drive eutrophication; toxins bioaccumulate. Understanding dissolved load is key to water‑quality management.