Question

III- Fill-in-the blank (1 point each) Stratosphere – plants – services – precipitation – troposphere – ultraviolet - sun - aquifers – resources 1. The two innermost layers of the atmosphere are the which supports life, and the which contains the protective ozone layer. 2- Widespread use of certain chemicals has reduced ozone levels in the and allowed more harmful radiation to reach the earth's surface. 3. The warms the planet and provides energy that use to produce food for themselves and for us and most other animals. IV-Short answer questions (4 points) 1- List 2 ways to deal with the sludge produced by sewage water treatment. Is it safe to use it as a fertilizer for crops?

Answer 1

III) Troposphere is the layer of atmosphere that immediately surrounds the surface and contains life. Above the troposphere a second layer called Stratosphere is present which contains Ozone layer and prevents UV from sun to reach the surface.

From this information the blanks in the question be filled as follows:-

1) The two innermost layers of the atmosphere are TROPOSPHERE, which supports life and STRATOSPHERE, which contains the protective Ozone layer.

2) Widespread use of certain chemicals has reduced the ozone levels in the STRATOSPHERE and allowes most harmful ULTRAVIOLET radiation to the earth's surface.

3) The SUN warms the planet and provides energy that PLANTS use to produce food for themselves and fir us and most other animals.

IV) Sludge is the semisolid reamins of waste water, left after waste water treatment. This sludge has very important uses.

The slugde contains biodegradable solids, thus on fermentation produces alcohol. Hence, it can be used as biofuel production.

Due to rich minerals the sludge can also be used as fertilizer in crop improvement. As the sludge contains high amounts of nitrogen, organic compounds and phosphates, Thus can be used as fertilizer in the agriculture.

Use of sludge is safe because it is biological but while using some health risks might result to humans due harmful chemicals and bacteria in the sludge. By taking a few precautions, it is safe to use.