**Sewage Treatment** Sewage treatment is a crucial process that removes harmful contaminants from wastewater to protect public health and the environment. The comprehensive process involves several stages of treatment to effectively purify wastewater before it is discharged back into water bodies. **What Happens to Leftover Sewage Sludge?** After sewage undergoes various treatment processes, a residual solid material remains, known as sewage sludge. This sludge is composed of organic and inorganic substances removed from the wastewater. The proper management of sewage sludge is essential to prevent environmental hazards and ensure the safety of ecosystems. **Management and Disposal of Sewage Sludge** Various methods are employed to manage and dispose of sewage sludge, including: * **Land Application:** Sludge can be spread on land as fertilizer, providing nutrients for agricultural crops. * **Sludge Composting:** Mixing sludge with organic materials, such as wood chips or compost, enhances its organic content and stabilizes it. * **Incineration:** High-temperature incineration burns the sludge, reducing its volume and eliminating harmful organisms. * **Anaerobic Digestion:** Sludge undergoes anaerobic decomposition to generate biogas and produce a stabilized sludge. The choice of sludge management method depends on factors such as local regulations, environmental conditions, and available resources. Proper management ensures that sewage sludge does not pose health risks or harm ecosystems.