What are two methods commonly used for sludge disposal?

The correct answer, which identifies land application and incineration as two common methods for sludge disposal, highlights effective strategies used in wastewater management.

Land application involves using treated sludge as a soil amendment, providing nutrients to crops and improving soil structure. This method can be beneficial as it recycles nutrients and organic matter into the land, supporting agricultural practices. However, it requires careful management to avoid contamination of soil and water resources.

Incineration is another critical method for sludge disposal. It involves burning the sludge at high temperatures, which significantly reduces its volume and eliminates pathogens. This process not only minimizes the physical footprint of the waste but also produces ash that can sometimes be disposed of in a landfill or further processed. Incineration offers a means to manage sludge that might otherwise require considerably more space for disposal.

Both methods are widely adopted due to their effectiveness in reducing the quantity of waste and their environmental management benefits, making them integral to modern wastewater treatment systems.