Clean tap water with zeolite filters

2002/04/29 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Mikrobiologia
• Osasuna

To avoid this problem, scientists have been looking for an effective filter for some time. A team of researchers at the University of Texas has worked with mineral zeolite and prepared a filter to eliminate infections that cause water pollution.

Zeolite, like clay, can expand in open, but unlike it, it does not melt in water. If it had the ability to capture microorganisms it could be used as a filter. But it is not so: in the water the viruses have an electric charge on the surface and the zeolite has the same load. Therefore, it repels microorganisms. To modify Zeolite's electrical charge, researchers have added a chemical used in conditioners and oral cleaning fluids: HDTMA.

Zeolite treated with HDTMA has been compared with untreated zeolite filters and sand surrounded by iron oxide, demonstrating that it is certainly the most effective. On the one hand, the untreated zeolite did not manage to eliminate the viruses from the water; on the other, the sand was a good filter in the laboratory, but in real state it did not give good results. The researchers found that prepared zeolite was able to eliminate 99% of viruses and 100% of E. coli, both in laboratory and in real state.

Besides very efficient, it is cheap. However, to decide its usefulness, they must investigate how long the filter lasts and whether it is toxic to humans.