Question

Choose the correct option from the below about biodegradable substance:
A. Biodegradable substances are easily decomposed by microorganisms and thus can easily mix into the soil again after a short interval of time.
B. They are not capable of maintaining a good mechanical integrity unless it’s completely degraded.
C. They are non-toxic in nature.
D. All compostable is always biodegradable but all biodegradable is not compostable.

Answer 1

Hint: The biodegradable substances can be used for many purposes. They can be used for biogas production which acts as a source of fuel and electricity. They can be used for composting. They act as a natural fertilizer that improves the fertility of soil by adding nutrients to it.

Complete answer:
With the increasing population, a lot of waste is generated every day. Some of these substances cause excess pollution to the environment while some can be decomposed off by the bacteria or other soil microorganisms. Hence, the classification of the substances and their proper disposal is important. There are two types of substances on the basis of their degradation by bacteria or not- biodegradable and non-biodegradable substances.
The biodegradable substances are the substances that can be degraded into simple natural components. The microorganisms are involved in the degradation of these substances. However, this process is not easy and it takes a long time to degrade these substances. Hence, option (A) is wrong.
Most of the biodegradable pollutants are organic but some can be inorganic such as gypsum. The biodegradable substances include domestic wastes such as kitchen wastes, paper, cloth, human excreta, sewage containing organic matter that can be degraded by bacteria, agricultural wastes etc.
The biodegradable substances can maintain good mechanical integrity even if not completely degraded. Hence, option (B) is wrong.
These substances can be decomposed by some methods such as composting method, anaerobic digestion and aerobic digestion. Hence, all compostable substances are biodegradable and all biodegradable substances are compostable. Hence, option (D) is wrong.
The biodegradable substances usually do not cause pollution. They are not very harmful for the environment. Hence, they are non-toxic and environmentally friendly.

So, the correct answer is “Option C”.

Note:
The substances that cannot be broken down into simpler substances even after a long time of their disposal are called non-biodegradable substances. Pesticides, lead and mercury are some examples. As they remain in the environment for a long time, they are very harmful and cause pollution.