Drinking Water Purification
Around the world, household drinking water purification systems, including a reverse osmosis step, are commonly used for improving water for drinking and cooking. Such systems typically include a number of steps: a sediment filter to trap particles including rust and calcium carbonate optionally a second sediment filter with smaller pores an activated carbon filter to trap organic chemicals and chlorine which will attack and degrade TFC reverse osmosis membranes a reverse osmosis (RO) filter which is a thin film composite membrane (TFM or TFC) optionally a second carbon filter to capture those chemicals not removed by the RO membrane optionally an ultra-violet lamp for disinfecting any microbes that may escape filtering by the reverse osmosis membrane in some systems, the carbon pre-filter is omitted and cellulose triacetate membrane(CTA) is used. The CTA membrane is prone to rotting unless protected by chlorinated water, the TFC membrane is prone to breaking down under the influence of chlorine. In CTA systems, a carbon post-filter is needed to remove chlorine from the final product water.