water safe to drink and treating waste water

how can water be purified

distillation but its expensive as it requires a lot of energy

method of desalination

reverse osmosis uses membranes to separate salt from water but needs energy to create high pressures that are needed

what treatment is required for the water before being released into environment

sewage works

what removal is needed

organic matter, harmful micro-organisms and chemicals

what happens to sewage sludge

its seperated, broken down by anaerobic digestion, when dried can give us fertiliser and renewable energy

how is water made fit to drink

pass through filter beds, add chlorine ozone or by passing it through ultra-violet light, sterilising, to reduce microbes