Novel polymer-based nanocomposites for application in heavy metal pollution remediation. Emerging Researcher Symposium

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1 Novel polymer-based nanocomposites for application in heavy metal pollution remediation Emerging Researcher Symposium Lara Kotzé-Jacobs 10 October 2012

2 Introduction: SA s water problem SA is a water scarce country Plagued by acid mine drainage, industrial effluent pollution, treatment shortfalls at municipalities and contaminated surface water discharges Accumulation of heavy metals and endocrine disrupters CSIR 2012 Slide 2

cancer Heavy metals can accumulate in food sources

3 Introduction: Heavy metals Cr, Ni, Cu, Pb, As etc. Exposure can cause liver and kidney damage and also cancer Heavy metals can accumulate in food sources through heavy metal contamination of soil and plants CSIR 2012 Slide 3

Removal of heavy metals Small volume applications: ion exchange

acid mine drainage: neutralisation and precipitation as well as

osmosis although very efficient is expensive (resins and

4 Removal of heavy metals Small volume applications: ion exchange Larger volumes eg. acid mine drainage: neutralisation and precipitation as well as reverse osmosis (membrane process) Ion exchange and reverse osmosis although very efficient is expensive (resins and membranes) Neutralisation and precipitation is not 100% effective at removing heavy metals at low concentrations <10ppm CSIR 2012 Slide 4

Adsorption for removal of heavy metals Most well known activated charcoal/carbon Adsorption of atoms, ions or molecules from a gas, liquid, or dissolved solid

5 Adsorption for removal of heavy metals Most well known activated charcoal/carbon Adsorption of atoms, ions or molecules from a gas, liquid, or dissolved solid to a surface surface phenomenon Adsorbent Adsorbate Absorption is a condition in which something takes in another substance- bulk phenomenon CSIR 2012 Slide 5

6 Why use polymers nanocomposites as adsorbents? Nanocomposites are composites of polymers and inorganic/organic material where at least one of the components are smaller than 100nm Relative affordability of polymer nanocomposites Relative ease of manufacture of polymer nanocomposites CSIR 2012 Slide 6

7 Nanocomposites Larger surface ~ Increased adsorption CSIR 2012 Slide 7

8 Materials and methods Polypyrrole Alumina <50nm Reagents are combined and polimerized with FeCl 3 to form the PPy/Alumina nanocomposite CSIR 2012 Slide 8

9 Analysis of adsorption efficiency Adsorption of Cr(VI) Adsorption is evaluated at different nanocomposite loadings, different ph s as well as initial heavy metal concentrations Additional studies include studies at 25, 35 and 45 C to determine thermodynamic parameters of adsorption Potable water < 0.05 ppm Cr(VI) Surface discharge < 0.1ppm Cr(VI) US EPA Cr(VI) free water Magnetic stirrer CSIR 2012 Slide 9

10 Characterisation: Scanning Electron Microscopy CSIR 2012 Slide 10

11 Characterisation: Transmission Electron Microscopy CSIR 2012 Slide 11

12 Characterisation: ATR-FTIR Wavenumber / cm-1 ATR-FTIR spectra of a) PPy/Alumina nanocomposite with b) Cr(VI) adsorbed CSIR 2012 Slide 12

13 Characterisation: X-Ray Photoelectron Spectroscopy CSIR 2012 Slide 13

14 Process of Cr(VI) adsorption Cr(VI) containing water Shake at 200rpm for 24hrs at 25 C Nanocomposite Analyse for Cr(VI) concentration using UV spectrophotometry Filter to separate material from water CSIR 2012 Slide 14

15 Results Nanocomposite loading study CSIR 2012 Slide 15

16 Results ph studies CSIR 2012 Slide 16

17 Results Kinetics studies CSIR 2012 Slide 17

18 Results Adsorption isotherms CSIR 2012 Slide 18

19 Results Regeneration experiments At At highercr(vi) low concentrations CSIR 2012 Slide 19

20 Results Co-existing ions CSIR 2012 Slide 20

Summary Material Characteristic PPy/Alumina PPy/Magnetite Max adsorption capacity (25 C) Time for 100% removal (100ppm, 150ppm, 200ppm) ~190mg Cr(VI)/g material 20min, 80min, 100min ~169 Cr(VI)/g

21 Summary Material Characteristic PPy/Alumina PPy/Magnetite Max adsorption capacity (25 C) Time for 100% removal (100ppm, 150ppm, 200ppm) ~190mg Cr(VI)/g material 20min, 80min, 100min ~169 Cr(VI)/g material 20min, 110min, 150min Kinetic model Pseudo-second order Pseudo-second order Isotherm model Langmuir Langmuir M. Bhaumik et al. / Journal of Hazardous Materials 190 (2011) Cr(VI) free water CSIR 2012 Slide 21 Magnetic stirrer

22 Conclusions Developed a PPy/Alumina nanocomposite Improved adsorption capacity for Cr(VI) when compared to Fe 3 O 4 nanocomposite and other low cost materials Regeneration up to 3 cycles was possible at low Cr(VI) concentrations Co-existing ion studies showed material specificity for Cr(VI) CSIR 2012 Slide 22

23 Acknowledgements Dr Arjun Maity, Supervisor Dr James Wesley-Smith, Nanocenter, TEM images Mrs Avashnee Chetty, Group leader CSIR 2012 Slide 23

24 Thank you Questions?

1-D and 2-D Carbon-Iron Nanohybrids Prepared with Ultrasonic Spray Pyrolysis for Cr (VI) Removal

1-D and 2-D Carbon-Iron Nanohybrids Prepared with Ultrasonic Spray Pyrolysis for Cr (VI) Removal Arvid Masud, John D. Atkinson, and Nirupam Aich Civil, Structural and Environmental Engineering 1 Nanomaterial