Perspectives are different frameworks from which to explore the knowledge around sustainable sanitation and water management. Perspectives are like filters: they compile and structure the information that relate to a given focus theme, region or context. This allows you to quickly navigate to the content of your particular interest while promoting the holistic understanding of sustainable sanitation and water management.
This document provides an easy to read and yet comprehensive introduction to the water treatment process with slow and rapid sand filters while particularly addressing the multi-barrier principle.
WHO (n.y): Chapter 12: Water Treatment. In: WHO (2009): WHO Seminar Pack for Drinking Water Quality. . URL [Accessed: 07.02.2012]