Which of the following is an organic impurity in sewage?

The correct answer is Human faeces.

Key Points

• Human faeces are an organic impurity commonly found in sewage.
• Faecal matter is rich in organic matter and contains various bacteria, pathogens, and undigested food particles.
• The presence of human faeces in sewage poses a risk to public health due to the potential transmission of diseases and contamination of water sources.
• Proper sewage treatment processes are necessary to effectively manage and eliminate human faeces to prevent environmental and health hazards.

Additional Information

• Phosphates:
  • Phosphates are inorganic compounds that can be found in sewage as an inorganic impurity.
  • Phosphates mainly come from detergents, fertilizers, and human waste that enter the sewage system.
  • Excessive levels of phosphates in sewage can contribute to water pollution and eutrophication when released into natural water bodies.
  • Controlling and reducing the phosphate levels in sewage is important for environmental protection and maintaining water quality.
• Nitrates:
  • Nitrates are inorganic compounds that can be present in sewage as an inorganic impurity.
  • Nitrates can originate from various sources, including agricultural runoff, industrial waste, and domestic sewage.
  • Elevated levels of nitrates in sewage can lead to water pollution and pose a risk to human health, especially when they contaminate drinking water sources.
• Metals:
  • Metals, such as lead, mercury, cadmium, and copper, can be present in sewage as inorganic impurities.
  • These metals can originate from various sources, including industrial discharges, domestic waste, and runoff from metal-contaminated areas.
  • Elevated levels of metals in sewage can have detrimental effects on the environment and human health.
  • Effective sewage treatment processes, including filtration and sedimentation, are employed to remove or reduce metal impurities in sewage before it is discharged or reused.