Question

What is sewage sludge?

Answer 1

1. Sewage sludge refers to the residual, semi-solid material that is produced as a by-product during sewage treatment of industrial or municipal wastewater.
2. Sewage sludge contains useful concentrations of nitrogen, phosphorus, and organic matter. The availability of the phosphorus content is independent of any prior sludge treatment, while nitrogen availability is more dependent on sludge treatment.
3. In addition to organic waste material, sewage sludge contains traces of many pollutants used in our modern society.
4. Although sewage sludge provides sufficient inorganic fertilizer to meet crop requirements for nutrients, the applications of sludge have some effects on crop yields.