Granada: New method for removing disinfectants from water

Licensing opportunity

Researchers from the Department of Inorganic Chemistry of the University of Granada have developed a material for adsorbing halide ions from drinking water. Chlorine and ozone are widely used for purifying drinking water, but the ions that are left behind can interact with organic matter to give the water a ‘medicinal’ smell or form potentially toxic chemicals. While activated carbon is widely used to absorb odours after water has been disinfected, it cannot remove the halide ions.

The discovery is the work of José Rivera Utrilla and Manuel Sánchez Polo.

Both chlorine and ozone are powerful bactericides but they produce by-products when they react with organic substances in untreated water.

So, for example, bromates, which are carcinogens, are produced when there are bromides in the water, while iodides react with organic matter to form iodomethanes which cause the medicinal smell in water.

The new material is coated with silver atoms, which adsorb halides in the water, forming silver halides. These are removed subsequently by running ammonia through the material, which can then be used again.

Apart from water purification, the process is likely to be attractive in industries which are large users of de-ionised water, such as pharmaceutical manufacturing.

The technology transfer office of the university, Oficina de Transferencia de Resultados de Investigación, is looking for partners to commercialise the research which has been patented.