Synthesis and application of Iron Oxide Nanoparticles for household - - PowerPoint PPT Presentation

PRATHNA TC

Post Doctoral Researcher (EU COFUND) Environmental Engineering & Water Technology

Synthesis and application of Iron Oxide Nanoparticles for household level water treatment

Email: p.thanjavur@unesco-ihe.org prathna.tc@gmail.com

• Background
• Aim and objectives
• Methodology
• Results
• Conclusion & Future Scope

OUTLINE

• Approximately 663 million people around the world lack access to safe drinking

water

• Targets of United Nations SDG- ensure safe and affordable drinking water by 2030

BACKGROUND

WHO/UNICEF (2015). Progress on Drinking-water and Sanitation 2015 Update. Joint-Monitoring Programme: World Health Organization and United Nations Children Education Fund, 1, 1. http://www.un.org/sustainabledevelopment/water-and-sanitation/

Worldwide distribution of Arsenic & Fluoride contamination

http://www.iupac.org/publications/ci/2008/3004/2_garelick.html http://www.unicef.org/wes/files/wfl3e.pdf

• WHO permissible limit in drinking water:
• As: 10 ppb
• F: 1.5 ppm
• Coexistence of arsenic and fluoride in aquifers has been observed in many places

with concentrations exceeding 100 ppb (As) and 30 ppm (F)

• Widespread

problem in rural areas where communities often depend

• n

groundwater as the sole drinking water source

• Simultaneous removal of As and F simplifies treatment process and reduces cost

Co-contamination of arsenic and fluoride in drinking water

WHO, Guidelines for Drinking Water Quality, Second edition, volume 1, recommendations, Geneva, WHO 1993 p57/pp114-121 J Qiao, Z Cui, Y Sun, Q Hu, X Guan, Front Environ Sci Eng, 2014, 8(2), 169

• The amount of water required is relatively less
• The process is less energy intensive
• Simple operation- no post treatment step
• Economic reliability
• Cost effective
• Possess magnetic properties for efficient separation
• Excellent sorbents for Arsenic (~95 mg/g) and Fluoride (~90 mg/g) at lower pH

Adsorption Why iron oxide?

Z Ren, G Zhang, JP Chen, J Colloid Interface Sci, 2011, 358, 230

• Ease of synthesis and availability
• Can be easily coated onto suitable support

Why nanoparticles? Iron oxide nanoparticles for household level water treatment

• Sorption occurs at the interface of solid and fluid phases, implying that a large

surface area of sorbent favours both sorption rate and capacity

• To synthesize iron oxide nanoparticles
• To evaluate the efficacy of the synthesized material in removing Fluoride and

Arsenic from contaminated water sources

• To utilize the insights from batch studies in scale up studies
• To design an affordable household level water purification device using the

synthesized nanoparticles

OBJECTIVES

FeCl3 + FeCl2 (1:5) in C2H5OH Addition of 14.7M NH3 at pH 9 Reaction continued at 50 C for 3 h Precipitate pelleted out and dried at 100 C

METHODOLOGY

• X Ray Diffraction
• Surface area analysis (BET method)
• Particle size analyzer
• Zeta potential
• Scanning Electron Microscopy-

Energy Dispersive Analysis X ray spectroscopy

CHARACTERIZATION

RESULTS

Zeta potential X ray diffraction Contd..

Scanning Electron Microscopy Particle size analysis- stability

Batch adsorption studies

pH=7.0, shaking speed=180 rpm, temperature= 20 ºC

qmax (µg/g) As (III) As (V) Current study 909.1 3333.3 Iron coated sand 2400 2400 Commercial iron oxide 460

B Petrusevski, J Boere, SM Shahidullah, SK Sharma, JC Schippers, 2002, J Water Supply Res Technol, 51.3, 135-144 LS Zhong, JS Hu, HP Liang, AM Cao, WG Song, LJ Wan, 2006, Adv Mater, 18(18), 2426-2431.

qmax (mg/g) Fluoride Current study 1.78 S doped Fe3O4/Al2O3 41 Sodium alginate immobilized Fe3O4 58.24

Adsorption isotherm

For a family of 4, requiring 20 L Water/day which uses ground water with As (V) concentration of 200 ppb,

• ~13 g of adsorbent required (with

regard to batch adsorption studies)

Calculations for amount of adsorbent required for household level water treatment

Arsenic Fluoride

Potential prototypes for household level water treatment

• Stable Fe3O4 nanoparticles of ~200 nm in diameter were synthesized and studied

for arsenic and fluoride adsorption potential.

• The maximum sorption capacity of the nanoparticles for As (III) and As (V) at pH 7

were ~ 900 µg/g and ~3000 µg/g respectively while it was 1.78 mg/g for fluoride.

• The nanoparticles were not effective in fluoride removal at the pH and

concentrations studied while they followed the Freundlich isotherm model and fitted well with Pseudo-first order reaction.

• Further surface modification of the nanoparticles may be required for increased

fluoride adsorption.

• Detailed studies would be required to provide insight into the various factors

affecting the adsorption of As (III) and As (V) by synthesized iron oxide nanoparticles.

CONCLUSION & FUTURE SCOPE

THANK YOU