Nanostructured surfaces

Ag0-doped metal oxyhydroxides adsorbents for drinking water treatment 

Sorochkina K.O. 1, Skyba M.I.1, Smotraiev R.V.1
1 Department of inorganic substances technology and ecology, Ukrainian State University of Chemical Technology. Prospect Gagarina, 8, Dnipro-49005, Ukraine. 
E-mail: kateryna.sorochkina@gmail.com

Developing an adsorbent with novel modes of action assumes great significance today due to the lack of safe drinking water in the world, especially in small communities. Recently, promising materials that can simultaneously clean and disinfect drinking water are nanostructured composite adsorbents.
Ag0-doped metal oxyhydroxides adsorbents were synthesized by combination of sol-gel and reagentless plasma-chemical methods. Full involvement of Ag+ and Ag0 impurities can be achieved with the sol-gel method by introducing the antibacterial agent under stirring into the previously formed metal oxyhydroxides sols based on Al(III) and Zr(IV) ions [1]. As the doping agents solutions of AgNO3 and Ag0 nanodispersion stabilized by sodium alginate (Ag0‑AlgNa) [2]. Initial Ag+ concentration is 0.5 g/dm3, the molar fraction of Ag+/Ag0 in the final product is 0.125 mol%.
It was establish, that granulation and additional treatment (as washing and drying at 373 K) of modified sols leads to formation of nanostructured sorbets with specific surface area from 310 to 540 m2/g and pore size >2 nm. At the same time, obtained data testify that Ag0‑doped metal oxyhydroxides sol and sorbent contain metallic silver particles due to the presence of absorption peaks at λ=410 nm for sol and maximum at angles of 38.1°, 44.3° and 64.4° on X-ray diffraction pattern.
Water treatment tests of adsorbents shows their high efficiency to reduce total solids, manganese ions, colony count 22°C and Coliform bacteria in the natural underground water. 

1.	Sorochkina K., Smotraiev R., Chepurna I. Zirconium and aluminum oxyhydroxides particles formation during sol–gel process // Colloids Surfaces A Physicochem. Eng. Asp.-2015.-484.-P. 56-61.
2.	Skiba M., Pivovarov A., Makarova A., Pasenko O., Khlopytskyi A., Vorobyova V. Plasma-chemical formation of silver nanodispersion in water solutions // Eastern-European J. Enterp. Technol.-2017.-6.-P. 59-65.