CLASS 7 Chapter 18 Wastewater Story
Short answer type questions Question1. What do you mean by sewage treatment? Question 2. What is sewage? Question 3. Why chlorine is used to clean water? Question 4. What is sewerage? Question 5. Why cleaning water is important? Question 6. What are the by-products of wastewater treatment? Question 7. What are aerobic and anaerobic …