https://www.khanacademy.org/science/kn-class-7-science/x2edacdad2354c760:wastewater-story/x2edacdad2354c760:journey-of-wastewater-sewage/e/journey-of-wastewater 2026-04-07T22:23:57.656416987Z Journey of wastewater Explore how wastewater travels from homes to treatment plants through manholes, sewers, and screening systems. This exercise explains sewage composition, the function of manholes and sewerage routes, and the key steps of wastewater treatment - including bar screening, grit removal, sedimentation, aeration, and sludge handling - while highlighting how each stage helps clean and recycle used water. Yajurva Joshi exercise