Question

Which of the following statements is wrong? (a) Biodcgradable materials can be broken for converting waste to grecnery. (b) DDT is a non-degradable pollutant. (c) Domestic wastcs arc biodegradable pollutants. (d) Oxygen demanding wastes arc not water pollutants.

Short answer

Statement (d) is wrong.

Step-by-step solution

Understand Biodegradable Materials

Biodegradable materials are substances that can be decomposed by bacteria or other natural organisms and thereby avoid pollution. These materials return to nature and can become nutrients for plants and animals. The statement (a) involving biodegradable materials breaking down to convert waste to greenery generally aligns with this understanding.

Identify Non-Degradable Pollutants

Non-degradable pollutants are substances that do not break down in the environment. DDT is a notorious non-degradable pollutant known for its persistence in the environment and accumulation in the food chain. Therefore, statement (b) is correct.

Assess Domestic Wastes

Domestic wastes, such as food scraps, paper, and organic material, are typically biodegradable, meaning they can decompose naturally. Thus, statement (c) correctly identifies domestic wastes as biodegradable pollutants.

Evaluate Oxygen-Demanding Wastes

Oxygen-demanding wastes are substances that consume oxygen when they decompose in water. These wastes can deplete oxygen levels, harming aquatic life, and are considered water pollutants. So, statement (d) is incorrect in saying that oxygen-demanding wastes are not water pollutants.

Conclusion: Identify the Wrong Statement

By examining each statement, it's clear that statement (d) is the incorrect one because oxygen-demanding wastes are indeed water pollutants.

Key concepts

Biodegradable Materials

Biodegradable materials are substances that can break down naturally over time. This process is carried out by microorganisms like bacteria and fungi.
When biodegradable materials break down, they return to the environment as harmless, even beneficial, nutrients.
Examples of biodegradable materials include food waste, paper, and certain types of plastics made from natural materials.

• They reduce pollution because they do not accumulate in the environment.
• They can restore nutrients to the soil, aiding plant growth.
• Using biodegradable materials helps in managing waste effectively.

Non-Degradable Pollutants

Non-degradable pollutants are substances that do not decompose naturally, or do so very slowly. These pollutants can persist in the environment for years, decades, or even longer.
A famous example is DDT, a banned pesticide that can still be found in the environment.
Non-degradable pollutants can accumulate in living organisms through the food chain, causing biological magnification.

• They pose long-term environmental hazards.
• They can affect wildlife and human health severely.
• Management and disposal of non-degradable pollutants are challenging and costly.

Oxygen-Demanding Wastes

Oxygen-demanding wastes are substances that consume oxygen when they decompose in water bodies.
Common examples include sewage, manure, and other organic waste.
When these materials enter water bodies, microorganisms break them down, consuming dissolved oxygen in the process.

• Reduced oxygen levels can harm or kill aquatic life.
• High levels of oxygen-demanding wastes can lead to dead zones in water bodies.
• They are major water pollutants and need proper treatment.

Domestic Waste

Domestic waste includes all kinds of waste generated from households. This can include food scraps, paper, packaging, and yard waste.
Many components of domestic waste are biodegradable, such as organic scraps and paper.
However, domestic waste also often contains non-biodegradable materials like plastics and metals.

• Properly separating and managing domestic waste can reduce environmental impact.
• Composting biodegradable waste can turn it into useful fertilizer.
• Recycling helps to manage the non-biodegradable portion of domestic waste more effectively.