A new article published in the journal AWWA Water Science by scientists from the Institute of Hydrodynamics of the Academy of Sciences of the Czech Republic describes the use of mixed adsorbents in water treatment.
Activated carbon adsorption is used in water treatment primarily for the removal of non-removable or very difficult-to-remove substances of both natural and anthropogenic origin by coagulation, as a tertiary stage of water treatment used worldwide. This is a process that is influenced by a number of factors, the most important is the choice of the type of adsorbent. This study describes the use of mixed adsorbents, specifically two types of granular activated carbon commonly used in water treatment plants, to remove the low-molecular fraction of algal organic matter (AOM) and pesticides – i.e. problematically removable substances. It was found that mixed adsorbents can be significantly more effective under certain conditions than individual adsorbents used separately. The AOM removal increased from 25%–29% using single GACs to 44% using a suitable adsorbent mixture; similarly, the pesticide removal increased from 52%–67% to 74%. The adsorbent ratio was the key influential factor. Additionally, the pH value also significantly affected the adsorption. Using a mixture of different adsorbents is a promising method for treating drinking water.