Case Study: Reusing Waste Water For Drinking Water Production

By Katariina Majamaa

Having access to clean and safe drinking water is an undisputable human need. It is well known that, globally, available freshwater sources like rivers and groundwater storages are decreasing, while the demand for potable water is increasing.

Households, on a daily basis, create sewage water from showers, washing machines and toilet flushing. Normally, this water is discharged back into a freshwater source after being treated,. However, it is a unused reserve of freshwater, which with additional treatment, can provide safe, quality potable water .

One way to tap into this unused water reserve is indirect potable reuse (IPR). IPR is a treatment process where highly treated municipal waste water is discharged into natural freshwater sources such as rivers or groundwater storages. Whenever waste water is reclaimed for human consumption, the treatment process must be reliable and capable of removing pathogens and other contaminants present in the water. Reverse osmosis (RO) is currently the only technique capable of removing the required pathogens and ultrafiltration (UF) has proven to be an excellent pretreatment solution to remove suspended solids and bacteria and help maximize the RO performance.