Question

Choose the correct option from the below about biodegradable substances:

• A. Bio-degradable 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 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

The correct option is C

They are non-toxic in nature.

The correct option is C.

Explanation of the correct option:

1. They are non-toxic.
2. The materials that can be broken down into basic natural components are called biodegradable substances.
3. The breakdown of these compounds involves bacteria which converts them into simpler substances.
4. The simpler substances are absorbed by the soil for their nutrition.
5. They do not cause any pollution to the environment and are not harmful because they are non-toxic as they contain mostly organic components like kitchen waste, paper, human waste, etc.

Explanation of the incorrect options:

Option A:

1. Bio-degradable substances are easily decomposed by microorganisms and thus can easily mix into the soil again after a short interval of time.
2. The materials that can be broken down into basic natural components are considered biodegradable substances.
3. The breakdown of these compounds involves bacteria. However, this process is difficult, and these compounds' degradation takes a long period.
4. Hence, it is an incorrect option.

Option B:

1. They are not capable of maintaining good mechanical integrity unless it's completely degraded
2. The majority of biodegradable contaminants are organic, although some like gypsum can also be inorganic.
3. Domestic wastes like kitchen wastes, paper, cloth, human excreta, sewage containing organic stuff that can be broken down by bacteria, agricultural wastes, etc
4. Therefore, biodegradable waste is capable of maintaining good mechanical integrity unless it's completely degraded.
5. Hence, it is an incorrect option.

Option D:

1. All compostable is always biodegradable but all biodegradable is not compostable.
2. Biodegradable substances mix with soil due to the action of microorganisms through many methods like aerobic digestion, anaerobic digestion, and composting.
3. Hence, all compostable is always biodegradable but all biodegradable is also compostable.
4. Hence, it is an incorrect option.

Final Answer: The correct statement regarding bio-degradable substances is that they are non-toxic in nature.