Transcript Chang Elliot sol 2014 sm

The Use of Alginate and Chitosan to Purify
Tree Distillates of Organic Contaminants
Elliot Chang
Princeton University
Class of 2016
Civil and Environmental Engineering
Smith-Newton Research Scholar
Measuring Techniques
Well-established Technology
• IRMS: Isotope Ratio Mass Spectrometry
• Chromium Reduction  D/H readings.
• CO2 bubbling  18O/16O readings.
----------------------------------------------------------------------------------New Technology
• IRIS: Isotope Ratio Infrared Spectroscopy
• Picarro Inc.’s Cavity Ring Down Spectroscopy.
• MCM: Micro-Combustion Module.
The Problem
• Assumption of ‘true’ value for tree water:
• “The true isotope ratio of extracted plant and soil water was
represented by samples cleaned using activated charcoal and
measured by IRMS.” (West and Dawson, 2010).
• This assumption  basis of several decades’ worth of
environmental studies.
• This assumption is false.
dD Values with Varying Measuring
Techniques: Ethanol Contamination
-36.5
dD value/ per mil
-37
0
0.5
1
1.5
2
2.5
-37.5
TRUTH
-38
IRMS
-38.5
IRIS with MCM
-39
IRIS
-39.5
IRIS with Activated Carbon
-40
-40.5
% contamination/ by volume
My Proposed Solution: Pre-treatment
• In addition to post-processing softwares, such as Picarro’s
ChemCorrect:
• Eliminate alcohol contamination through the use of different
adsorbent (activated carbon is NOT effective):
• USE ALGINATE BIOSORBENT TO REDUCE CONTAMINATION.
Results: d18O
d18O with Varying IRIS Treatments
-6.05
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
-6.1
d18O/ per mil
-6.15
IRIS
IRIS with Alginate
-6.2
IRIS with Activated Carbon
TRUTH
-6.25
-6.3
-6.35
Addition of Ethanol/ % volume
Results: dD
dD with Varying IRIS Treatments
-38.6
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
-38.8
dD/ per mil
-39
IRIS
IRIS with Alginate
-39.2
IRIS with Activated Carbon
TRUTH
-39.4
-39.6
-39.8
Addition of Ethanol/ % volume
Conclusions
Alginate looks to be a promising pre-treatment process.
Beats the standard of using Activated Carbon.
Statistical significance: Alginate makes a difference.
Alginate in combination with IRISmore accurate than IRMS.
Important note: Precision dictated by application.
dD Values with Varying Measuring Techniques:
Ethanol Contamination
-36.5
-37
0
0.5
1
1.5
-37.5
dD value/ per mil
•
•
•
•
•
2.5
TRUTH
-38
IRMS
IRIS with MCM
-38.5
IRIS with Alginate
-39
IRIS
-39.5
IRIS with Activated Carbon
-40
-40.5
2
% contamination/ by volume
Questions & Comments?
Thank you.