Potable water treatment

Where does the potable water (drinking water) come from?
There are two major drinking water sources: surface water (e.g. lake, river and ocean) and ground water (water located under the ground).

For example, large part of the drinking water in Oslo is from lakes around the city.

What is the problem?
Raw water may contain vectors and hazardous chemicals that can be the cause of health problems. Therefore, water from the source needs to be treated before distributing to the society. Various treatments are currently applied, those differ from place to place.

Surface water contains natural organic matters (NOM) that originated from the decomposition of leaves, plants and animals. NOM is a common name and, thus, has a large variety in size and structure. Current technologies applied in the drinking water treatment can remove up to 90% of the NOMs, however, difficult to remove small sized NOMs in an efficient way.

NOM gives color to the water. Photos bellow show tap water taken at the laboratory in Oslo (right) and water treated by reverse osmotic (RO) membrane (left). As you can see, the tap water is colored, yellowish, due to the remaining NOMs.

Major challenges of today
NOMs gives color to the water. In addition, it can form carcinogen when reacted with chlorine.

Pesticides in the water source are another concern as they can have high health risks.

Both NOMs and pesticides contain aromatic components and are rather stable. Various studies are on going to treat these water containing these species, such as using adsorbents, membrane filtrations to separate out them.

We are working on…
This project targets to develop a new technology that can decompose organics (e.g. NOMs and pesticides) in water by a help of membranes and photo-catalysis.

Published October 7, 2008