Question

Match the column 1 with column II and mark the appropriate choice. $$ \begin{array}{|l|l|l|l|} \hline \text { (A) } & \begin{array}{l} \text { Toxic heavy } \\ \text { metals } \end{array} & \text { (i) } & \text { Domestic sewage } \\ \hline \text { (B) } & \text { Microorganisms } & \text { (ii) } & \begin{array}{l} \text { Industries and } \\ \text { chemical factories } \end{array} \\ \hline \text { (C) } & \text { Organic wastes } & \text { (iii) } & \text { Chemical fertilizers } \\ \hline \text { (D) } & \text { Plant nutrients } & \text { (iv) } & \begin{array}{l} \text { Discharge from food } \\ \text { processing factories } \end{array} \\ \hline \end{array} $$ (a) \((A) \rightarrow(\) i \(),(B) \rightarrow\) (iii), (C) \(\rightarrow\) (ii), (D) \(\rightarrow\) (iv) (b) (A) \(\rightarrow\) (iii), (B) \(\rightarrow\) (iv), (C) \(\rightarrow\) (i), (D) \(\rightarrow\) (ii) (c) (A) \(\rightarrow\) (iv), (B) \(\rightarrow\) (ii), (C) \(\rightarrow\) (iii), (D) \(\rightarrow\) (i) (d) (A) \(\rightarrow\) (ii), (B) \(\rightarrow\) (i), (C) \(\rightarrow\) (iv), (D) \(\rightarrow\) (iii)

Short answer

(A) \rightarrow (ii), (B) \rightarrow (i), (C) \rightarrow (iv), (D) \rightarrow (iii)

Step-by-step solution

Match Option A

Toxic heavy metals such as lead, mercury, and arsenic are typically discharged from industries and chemical factories. So, match A with ii.

Match Option B

Microorganisms are commonly present in domestic sewage because sewage contains waste from human activity, including human waste. Match B with i.

Match Option C

Organic wastes are often produced from the discharge from food processing factories as they handle various organic materials that can become waste. Therefore, match C with iv.

Match Option D

Plant nutrients usually refer to chemical fertilizers which are used to promote plant growth. Hence, match D with iii.

Key concepts

Toxic Heavy Metals

When we talk about toxic heavy metals, we're referring to elements such as lead, mercury, arsenic, cadmium, and chromium. These metals are dangerous because they are poisonous at low concentrations and tend to accumulate in the bodies of living organisms, causing various health issues, including neurological damage and organ failure.

For instance, take lead. It's found in industrial emissions and can also be present in old paint and plumbing fixtures. Once it's in the environment, lead can persist for a long time and has been linked to developmental problems in children.

Mercury, another toxic heavy metal, comes from industrial processes but can also be emitted naturally from volcanoes. It is most harmful in its methylmercury form, where it can bioaccumulate in fish and, when consumed, in humans, leading to serious neurological health problems.

Domestic Sewage

Domestic sewage is wastewater that comes from residential areas and includes a mix of household waste products. It typically contains a range of organic materials like food scraps, human waste, detergents, and microorganisms. The organic matter in sewage can break down in water bodies, often leading to an increased demand for oxygen in aquatic ecosystems, a condition known as eutrophication.

It's not just the organic matter that's an issue, though. Sewage can also contain harmful pathogens which can cause disease if not adequately treated before being released into the environment. This is why effective sewage treatment plants are crucial for public health and environmental protection.

Treatment plants use biological, chemical, and physical processes to remove pollutants from sewage before its release. However, untreated or improperly treated sewage can still end up in waterways, causing contamination.

Organic Waste

Organic waste typically refers to material that comes from living organisms or was recently alive. This includes things like leftover food, garden trimmings, and any other biodegradable material.

In the context of the exercise, organic waste from food processing factories can include a wide variety of materials, ranging from vegetable peels and meat byproducts to outdated or spoiled food products. These organic wastes can lead to several environmental challenges if not handled properly.

For instance, when organic waste decomposes in landfills, it generates methane, a potent greenhouse gas that contributes to climate change. Alternatively, composting is a way to turn organic waste into a valuable fertilizer for plants, reducing the need for chemical fertilizers and enhancing soil health.

Chemical Fertilizers

Speaking of chemical fertilizers, these are substances added to soil to supply one or more plant nutrients essential to the growth of plants. Common components of fertilizer are nitrogen, phosphorus, and potassium.

While chemical fertilizers can significantly boost crop yields, their overuse can have damaging effects on the environment. Excess nutrients can wash into rivers and lakes, stimulating excessive algae growth that suffocates aquatic life - a process known as algal bloom.

Another concern is that overuse of chemical fertilizers can lead to soil degradation over time. As the fertilizers break down in the soil, they can alter the pH levels, making it less fertile. Moreover, repeated use can lead to a buildup of salts in the soil, which can harm plants. Therefore, it's essential for sustainable farming practices to ensure the right balance and use of fertilizers.