Biodegradable Substances Explained

Biodegradable substances are materials that can be broken down naturally by microorganisms (like bacteria and fungi) into simpler components such as water, carbon dioxide, and organic matter. This decomposition process occurs over a relatively short period.

Analyzing Waste Materials for Biodegradability

Let's examine each option to determine its biodegradability:

• Spoilt food: This consists of organic materials that are readily decomposed by microorganisms. Therefore, spoilt food is biodegradable.
• Plastic bags: Most conventional plastic bags are made from synthetic polymers derived from petroleum. These materials are highly resistant to natural decomposition processes and can persist in the environment for hundreds of years. Thus, plastic bags are non-biodegradable.
• Waste paper: Paper is primarily made of cellulose, a natural polymer that can be broken down by many microorganisms. Therefore, waste paper is generally considered biodegradable.
• Vegetable peels: These are organic plant materials that decompose quickly when exposed to natural environmental conditions and microbial activity. Therefore, vegetable peels are biodegradable.

Identifying the Non-Biodegradable Substance

The question asks to identify the substance that is NOT biodegradable. Based on the analysis above, plastic bags are the only option that does not decompose naturally and quickly.