Question

Composting of organic matter involves
1. Anaerobic digestion
2. Aerobic digestion
3. Fermentation
4. Combustion

Answer 1

Correct Answer - Option 2 : Aerobic digestion

The correct answer is Aerobic digestion.

• Composting is an aerobic method of decomposing organic solid wastes. It can therefore be used to recycle organic material.
• The process involves the decomposition of organic material into a humus-like material, known as compost, which is a good fertilizer for plants.
•  It requires the presence of air.
• Organic matter includes plant materials and some animal manures. Organic materials used for compost should include a mixture of brown organic material (dead leaves, twigs, manure) and green organic material (lawn clippings, fruit rinds, etc.). Brown materials supply carbon, while green materials supply nitrogen.

• Anaerobic digestion 
  • It is the process by which organic matter such as animal or food waste is broken down to produce biogas and biofertilizer.
  • This process happens in the absence of oxygen in a sealed, oxygen-free tank called an anaerobic digester.
• Aerobic digestion 
  • It is a process in sewage treatment designed to reduce the volume of sewage sludge and make it suitable for subsequent use.
  • More recently, technology has been developed that allows the treatment and reduction of other organic waste, such as food, cardboard, and horticultural waste.
• Fermentation 
  • It is a metabolic process that produces chemical changes in organic substrates through the action of enzymes.
  • In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen.
• Combustion
  • ​It is a chemical process in which a substance reacts rapidly with oxygen and gives off heat. The original substance is called the fuel, and the source of oxygen is called the oxidizer. The fuel can be a solid, liquid, or gas, although for airplane propulsion the fuel is usually a liquid.