Question

9. ?Using the following figure, describe how BOD effects oxygen concentration and fish.?

10.What is the difference between an oligotrophic and eutrophic lake? What is anthropogenic eutrophication?

11.How can groundwater become contaminated?

12.What can you do at home to reduce water pollution?

Answer 1

9. ​using the following figure, describe how BOD effects oxygen concentration and fish.​

Free non compound oxygen present in the water is known as Dissolved oxygen and it is one of the important parameter through which the quality of the water is assessed. And high or low dissolved oxygen level is harmful to aquatic life, so a desired dissolved oxygen is very important for fishes to survive. When there excess amount of biological oxygen demand (BOD) the dissolved oxygen level will decrease. BOD represents the amount of dissolved oxygen the aerobic organisms need to break down the organic material present in the water body. As they will consume more oxygen, the dissolved oxygen level will decrease. As shown in the figure, near sewage spill, the BOD is high, at 50 km the dissolved oxygen is very low at these places, the fishes cannot survive due to the lack of required dissolved oxygen for them.

10.What is the difference between an oligotrophic and eutrophic lake? What is anthropogenic eutrophication?

The nutrient poor water is known as oligotrophic and the lakes with nutrient poor water are oligotrophic lakes and because of less nutrients the primary productivity in these lakes will be less and you will not find any visible life here. The nutrient rich water is known as eutrophic and lakes with nutrient rich water are known as eutrophic lakes and here primary productivity is high and we can see visible life here. Anthrogenic eutrophication is the water pollution which is caused by the excessive plant nutrients and here the aging lakes or ponds will accumulate the plant nutrients and is a natural process.

11.How can groundwater become contaminated?

Humans are responsible for the contamination of ground water and it is getting contaminated with gasoline, chemicals, salt contamination, leakage and spills, pesticides and fertilizers and waste disposals.

12.What can you do at home to reduce water pollution?

Make sure you what you are throwing down in your sink or toilet, try to use environmentally friendly products (washing powder, cleaning agents, toiletries etc), don’t throw garbage in fresh water, clean the litter in water filled areas, try to contain and compost yard waste, conserve water sue,