Tag: zoology

• Anaerobic digestion is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen.
•  The process is used for industrial or domestic purposes to manage waste and to produce fuels. 
• Hence, Wastewater treatment generates a large amount of sludge, which can be treated by anaerobic digesters.
• So, the correct answer is 'anaerobic digesters'.

Chlorine is a powerful disinfectant that can kill the bacteria and viruses by destabilizing the chemical bonds of the pathogens. So, it is used in purification of water.

Answer is option C i.e. "Conversion of milk to curd"

Domestic sewage consists biodegradable organic matter and easily decomposes by the micro-organisms. These microorganisms can multiply using these organic substances as substrates and hence, utilize some of the components of sewage. Micro-organisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result, there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. This causes mortality of fish and other aquatic creatures. 

Decay is what happens when dead animals and plants break down. The key factors involved in decay are: Temperature, Amount of oxygen, Amount of water and the presence of microorganisms. Microorganisms are important in decay. For example, they are used to break down human waste (sewage) and plant waste (compost). Decay recycles important nutrients for plant growth.