Waste water treatment includes physical, chemical as well as biological processes.

The steps involved in the treatment are as follows:

• Screening - Waste water is passed through bar screens. Large and easily visible objects such as sticks, cans, plastic packets and napkins are removed.
• Grit and sand removal - Water then enters a grit and sand removal tank. Water is passed slowly to allow sand, grit and pebbles to settle down.
• Water is allowed to settle in a large tank which slopes towards the middle. Solids (e.g. faeces) settle at the bottom and are removed with a scraper. This is sludge. A skimmer removes the floatable solids (e.g. oil and grease). Water so cleared is called clarified water.
• The sludge is then transferred to a separate tank where anaerobic bacteria decompose it. The biogas produced in the process can be used to produce electricity.
• Aeration: Anaerobic bacteria are allowed to grow by pumping in air into clarified water. Bacteria consume the unwanted matter still present in the clarified water.
• From the aeration tank, treated water is sent to another sedimentation tank, where, after several hours, the suspended microbes settle down as activated sludge and the water from the top is removed. As this activated sludge is about 97% water, sand drying beds or machines are used to remove water. The dried sludge is now used as manure, thereby returning the organic matter and nutrients to the soil.
• The treated water has a very low level of organic and suspended matter and is hence discharged into seas, rivers or into the ground.
• Sometimes, chemicals such as chlorine and ozone are used to disinfect water before releasing it into the distribution system.

It is evident that media has immense influence on the people by focusing on few issues. This can have negative effect on our democracy. The media also plays an important role in deciding what stories to focus on, and therefore, decides on what is newsworthy. Sometimes, it misses out on more significant events and covers unnecessary events that may attract people. If media focuses on one side of the issue, it can influence our thoughts and actions. People may make biased decisions. Rather, media should provide a balanced report and leave it to the audience to decide. A balanced report will help people in a democracy make right informed decisions. Examples:  1.On a positive note, media highlighted social crimes under the name of "honour killing" by "caste panchayats" or narrow-minded families and communities. This helped people become aware of the social issue.  2.India is the second most agriculture led country after USA. On a negative side, media (specially private channels) hardly broadcasts programmes on agriculture to educate farmers. Rather these channels air "SaasBahu serials" 24 hours a day. Even news channels have dedicated shows to cover "Page 3 masala", but they hardly run any show on technical education. 

As soon as possible

1. Filtration: The wastewater is passed through bar screen. Large objects; like rags, sticks, plastic bags, cans, etc. are removed in this process.

2. Grit and Sand Removal: The wastewater is slowly passed through the sedimentation tank. Grit, sand and pebbles settle down at the bottom.

3. Sedimentation: Water is then sent to the sedimentation tank. Solids; like faeces settle at the bottom. Floatable impurities; like oil and grease float on the surface. A scraper removes the faeces from the water. The impurity thus collected is called sludge; which is sent to the sludge tank. The sludge can be used to produce biogas or to produce manure. A skimmer removes the floatable impurities. Now, the water is called clarified water.

4. Aeration: Air is pumped into clarified water so that bacteria can proliferate. Bacteria consume the human waste. It leaves food waste, soap and other unwanted materials in the water. The microbes settle down at the bottom after several hours. Water is then removed from the top. This water is fit for irrigation and can be used for that purpose.

5. Chlorination: Water purified through aeration is not fit for human consumption. It needs to be treated with chlorine. For this, bleaching powder is added to the water. The chlorine kills whatever germs may be left in the water. After chlorination, the water is fit for drinking.

Hampi which is located in the Krishna-Tungabhadra basin formed the nucleus of the Vijayanagara Empire founded in 1336. A well-fortified city is revealed by the magnificent ruins at Hampi. The construction of walls was done using a technique in which stone slabs were wedged together by interlocking. No mortar or cementing agent was used in this construction. Hampi had a distinctive architecture.

The Indian Constitution is known as a living document because it is not static and can be amended and changed over the period of time according to the needs and requirements of the society. The fact that Indian Constitution has been amended about 100 times makes it a living document.

Waste water treatment includes physical, chemical as well as biological processes.

The steps involved in the treatment are as follows:

• Screening - Waste water is passed through bar screens. Large and easily visible objects such as sticks, cans, plastic packets and napkins are removed.
• Grit and sand removal - Water then enters a grit and sand removal tank. Water is passed slowly to allow sand, grit and pebbles to settle down.
• Water is allowed to settle in a large tank which slopes towards the middle. Solids (e.g. faeces) settle at the bottom and are removed with a scraper. This is sludge. A skimmer removes the floatable solids (e.g. oil and grease). Water so cleared is called clarified water.
• The sludge is then transferred to a separate tank where anaerobic bacteria decompose it. The biogas produced in the process can be used to produce electricity.
• Aeration: Anaerobic bacteria are allowed to grow by pumping in air into clarified water. Bacteria consume the unwanted matter still present in the clarified water.
• From the aeration tank, treated water is sent to another sedimentation tank, where, after several hours, the suspended microbes settle down as activated sludge and the water from the top is removed. As this activated sludge is about 97% water, sand drying beds or machines are used to remove water. The dried sludge is now used as manure, thereby returning the organic matter and nutrients to the soil.
• The treated water has a very low level of organic and suspended matter and is hence discharged into seas, rivers or into the ground.
• Sometimes, chemicals such as chlorine and ozone are used to disinfect water before releasing it into the distribution system.

The speed at which the human heart beats is termed as the heart rate. To get an accurate reading, place your finger on an artery and count the pulses upto 60 seconds. Generally, a lower pulse or a heartbeat indicates that a person is physically fit and the heart muscles are in a good condition.

Our atmosphere has 78% of nitrogen but this atmospheric nitrogen cannot be utilised directly by plants or animals. It has to be first converted into nitrogen compounds. This process of converting nitrogen gas of atmosphere into compounds of nitrogen is called nitrogen fixation. The nitrogen gas of atmosphere can be fixed by

1. Certain nitrogen fixing bacteria present in the soil.
2. By Rhizobium bacteria present in the root nodules of leguminous plants
3. By blue-green algae
4. By lightning

The nitrogen fixing Rhizobium bacteria live in the root nodules of leguminous plants like peas, beans, etc. and show symbiotic relationship.