Synthesis of TiO2-based Nanomaterials and their Application in Arsenic Removal from Drinking Water
Event details
| Date | 19.11.2008 |
| Hour | 14:15 |
| Speaker | Dr Deedar Nabi |
| Location |
GR C1 564
|
| Category | Conferences - Seminars |
Pure TiO (108 nm) and iron-doped TiO,Fe0.0063Ti0.9937O2, (65 nm)
nanoparticles synthesized via sol-gel process were used along with
General Purpose Reagent (GPR) TiO2 (325 nm) for studies of Arsenic
removal from drinking water. These nanopatricles were in 100 % anatase
crystalline phase. Energy dispersive elemental analysis indicated better
percentage purity of lab synthesized nanoparticles as compared to GPR
TiO. Yellow orange color of doped TiO22 showed a red shift in absorption
wavelength from 387.5 nm to around 435 nm, thereby making the doped
species visible light responsive. Pure TiO2 nanoparticles were
successfully immobilized by generating titania-coated sand (TCS) singly
(TCS-1) and doubly (TCS-2) via the sol-gel process.
To see the effects of different conditions on Arsenic adsorption, five
systems were used, viz., As(V) in Air-Light , As(III) in Air-Light,
Air-Sunlight, Air-Dark and Nitrogen-Dark conditions. Kinetics of
adsorption followed pseudo-second order rate law except for
As(III)-Air-Light system which followed Elovich model. Adsorption of
Arsenic on the adsorbents followed Freundlich and Langmuir model.
Iron-doped TiO showed higher affinity for Arsenic than pure TiO22 which
in turn showed greater affinity than GPR TiO2. Similarly, TCS-2 showed
higher Arsenic affinity than TCS-1. Removal of As(III) was higher in
light and oxidizing conditions than in dark and anoxic conditions.
From pH dependence behavior, Point of Zero Charge of the nanoadsorbents
was estimated to be around 7. Arsenic adsorption decreased with increase
in pH. In TCS column test, 98% of As(V) and As(III) was removed with no
leaching of TiO up to 1500 and 1450 bed volumes, respectively.
Links
Practical information
- General public
- Free