RBSE Class 7 Science Notes Chapter 18 Wastewater Story

These comprehensive RBSE Class 7 Science Notes Chapter 18 Wastewater Story will give a brief overview of all the concepts.

RBSE Class 7 Science Chapter 18 Notes Wastewater Story

→ Used water is wastewater. Wastewater could be reused.

→ It has been reported that more than one billion of people have no access to safe drinking water. 

→ On the World Water Day, on March 22, 2005, the General Assembly of the United Nations proclaimed the period 2005-2015 as the International Decade for action on “Water for life”.

→ Cleaning of water is a process of removing pollutants before it enters a water body or is reused. This process of wastewater treatment is commonly known as “Sewage Treatment”.

→ Sewage is a complex mixture containing suspended solids, organic and inorganic impurities, nutrients, saprophytes and disease causing bacteria and other microbes.

Flow chart of wastewater treatment

→ Treatment plants reduce pollutants in.wastewater to a level where nature can take care of it.

→ Poor sanitation and contaminated drinking water is the cause of a large number of diseases.

→ Untreated human excreta is a health hazard. It may cause water pollution and soil pollution.

→ When underground sewerage systems and refuse disposal systems are not available, the low cost onsite sanitation system can be adopted.