Sanjana and her parents, who are residents of a metropolitan city, were passing through the sides of a river. They noticed the illegal discharge of effluents from local industry into the river.
Effluent discharge sometimes referred to as 'wastewater', is liquid waste produced and discharged by any industrial or commercial premises, such as a food processing factory or manufacturing business.

    

Her parents reported the unlawful activity to the police and sanitation department. What will be the consequences of the discharge of effluents into the river on people living in that area? State the values that are exhibited by Sanjana's family.

Tiger toilet technology was first developed by "Biofilcom" which was funded by Bill and Melinda Gates Foundation. The toilet is a vermi processing toilet that was first installed in Myanmar, Uganda and India in a humanitarian camp.

General flush toilets we use nowadays, use a huge amount of water, and sewerage disposal needs hefty effort for their treatment. Tiger toilets seemed a boon to the places where water is scarce.

These toilets contain a worm tank where a species of earthworm known as tiger worms are filled to it, and they act upon human faeces. These toilets are effective in producing less bio waste than the regular toilets. These tanks are needed to be emptied after $4-5$ years and the biosolids from them could be further utilised.

(a) Garv read the above article but did not understand what biosolids are. Help him know about biosolids.

(b) How can biosolids be utilised?

Neela is a naughty young girl who is consistently on a run in the whole house as well as their society. Neela has been asking for a toy for quite some time now, but her parents promised to buy her one on her birthday. Neela's grandparents have come to their place, and she was very happy and joyous to see them. She hugged and kissed both her grandparents. Her grandparents have brought many gifts for her, and she opened all of her presents one by one. She was surprised to see the same toy that she has been asking from her parents. She was overjoyed and after kissing her grandfather, she went on to play with her new toy along with her friends. Neela in a hurry, took off the toy's plastic wrapping and threw it in the drain outside her house.

a) What can be the result of Neela's carelessness?

b) What else might she have done instead of throwing the plastic down the drain?

Mohit noticed that his mother is preparing to make finger chips. She requested Mohit's assistance in making finger chips. Mohit was overjoyed, and he decided to assist her. She instructed him to bring some potatoes and properly wash them. He took some potatoes, cleaned them with water and gave it to her mother. She began to cut the potatoes into finger-like shapes while directing him to get the oil from the little can. He took the can, opened the bottle lid, and detected a foul odour. He told his mother that it smells awful. She smelled the oil as well and instructed him to put it down the drain as the oil has gone bad. She then opened up a new packet of oil and used it to prepare fries.

Answer the following questions:

a) Why should oils and fats not be thrown in the drains?

b) What we can do with vegetable-washed water instead of pouring it into the drain?

Prakyath resides next to a river. He observed that all of his neighbours' trash was dumped into the river. Prakyath asked them, "Why are you people pouring trash into the river?" They defended their behaviour by claiming that the amount of trash they dump is negligible in comparison to the amount of waste that the nearby factories dump into the river.

a) Are Prakyath's neighbours doing the right thing? Give Reason.

b) Is it possible to reduce the problems relating to disposal of garbage?

Nitin has recently learned about waste water treatment in his school. His mother took him to a waste water treatment facility. He discovered that waste water containing cans, plastic bags, pebbles, faeces, and rags was moving within the wastewater in treatment plant. The worker said that after a few steps, all pollutants would be eliminated, and the water will be used for other activities.

Answer the following questions:

a) Which part of a wastewater treatment plant removes large objects like cans, plastic packets and rags?

b) How pebbles are removed?

Mohith is a class 7 student, and he is flying with his parents for the first time. After sometime of the flight takeoff, he felt the need to use the restroom, but the thought of human excreta falling outside over someone's body made him feel uncomfortable. He shared this thought with his parents. They conveyed him that in aeroplanes a special type of toilets are used, and the excreta doesn't fall onto the ground. Finally, he agreed to go washroom.

What type of toilets are suitable in aeroplanes? 

Sanju's family went to a resort this summer's holiday. The resort had a very nice swimming pool and the family had a wonderful time at the resort. One day, Sanju observed that one of the resort's employee was adding some chemical to the pool. Sanju asked about this to his father. His father answered that the chemical was put for purifying swimming pool's water. Sanju still has several questions that his father was unable to answer.

Can you help him clear up his following doubt:

(a) What kind of chemical(s) were put in the pool?
(b) What kind of impurities does these chemical remove?

Santosh is a fisherman and used to go fishing every day. One day, when he reached near the riverbank, he discovered numerous dead fish on the riverbank. This is because factories discharge many chemical wastes into the water bodies. This creates disturbance in the aquatic life and leads to the death of many aquatic animals such as fishes, crabs, etc.

From the above understanding, explain the types of impurities present in sewage.