Class 7 Biology (English Medium)

Class 7 Biology – CHAPTER 13 : WASTEWATER STORY

Wastewater Story Water – Our Lifeline Sewage Types of Impurities Examples Organic impurities Human faeces, animal wastes, oil, urea, pesticides,herbicides, fruit and vegetable wastes Inorganic impurities Nitrates, phosphates, metals Nutrients Phosphorus and nitrogen Bacteria Those which cause diseases such as cholera, dysentery andtyphoid Sources of wastewater: Treatment of sewage in cities and towns: If sewage

Class 7 Biology – CHAPTER 13 : WASTEWATER STORY Read More »

Scroll to Top