PETpla.net Insider 08 / 2014

PET - THE NEXT GENERATION 27 PET planet insider Vol. 15 Respecting values in effective dialogue www.krones.com drink technology India 2014 Mumbay, 25 – 27 September Hall 01 H21 Water disinfection project in Vietnam ness of Sodis against a wide range of germs such as bacteria (cholera, typhus, dysentery, etc.), viruses (polio, hepatitis, etc.) and parasites (giardia, cryptosporidium, amoeba, etc.). Research into the question of why the germs die revealed that bacteria die because membrane proteins as well as enzymes of the respiration are being damaged by UV-A radiation. This damage is evidently so severe that the bacteria can no longer repair it. The role of PET The PET bottle plays a key role in the Sodis method. PET is recom- mended because the bot- tles are light, do not break and are easy to obtain in many regions of the world. However, clear glass bot- tles or special bags can also be used. Reports regarding substances in PET bot- tles that may be a risk to health are worrying users of the Sodis method. Therefore, a number of research institutions tested the scientific accuracy of these reports and car- ried out their own analy- ses of substances such as antimony, adipates, phthalates, acetaldehydes and formaldehydes. One focus was the question of whether formalde- hydes and acetaldehydes are transferred from the PET bottles to the water when the Sodis method is applied, and if so, in what quantities. It was found that exposure to the sun has no effect on the concen- tration of acetaldehydes, though the concentration of formaldehydes does increase with the length of exposure. However the concentrations of aliphatic aldehydes remained far below the state regulatory limit for drinking water in all samples. These studies show that when the Sodis method is applied correctly with PET bottles, there is no danger to human health. Eawag set up projects in develop- ing countries to make sure that the method was made available to the people who needed it most urgently. At the moment more then 5 million people in 24 countries in Africa, Asia and Latin America use the Sodis tech- nique to disinfect the drinking water. www.sodis.ch