This research mainly focus on developing an efficient product that will be effective for remediation during groundwater treatment. It gives in-depth analysis on in-situ oxidation techniques for groundwater remediation.

1. PRODUCT DEVELOPMENT OF
CONTROLLED RELEASE CANISTERS
FOR GROUNDWATER REMEDIATION
- AKINTUNDE OLUWATIMEHIN
OCT-11-2022
Supervisor: Alexis Carpenter

2. Groundwater contamination occurs because of either;
Man-made products like gasoline, oil, organic salts etc.
Untreated waste like septic tanks, storage tanks etc.
A&T Farm Situation
Gasoline release in underground storage 10 years ago.
AxNano pilot-tested remediation products on A&T farm
Cleaning up is important to stop contamination influx into
freshwater bodies around the farm consumed.
2
BACKGROUND STORY

3. 3
Method for Clean-up Process
In-Situ Chemical Oxidation
• Involves the use of technology for remediation of
contaminated area.
• Used for treatment of chlorinated organic solvents and
petroleum hydrocarbons.
Can Be Done By;
• Excavation
• Injection
How It Works
• It uses chemical oxidants.
• Oxidants are passed through permeable reactive barriers.
Image credit: Siegrist, Robert L., Michelle Crimi, and Thomas J. Simpkin, eds. In situ chemical oxidation
for groundwater remediation. Vol. 3. Springer Science & Business Media, 2011.

4. 4
AxNano method of remediation
In-situ method
Deployment of canisters with sleeves
(oxidant-packed sleeves) into site of
contamination
Shortcomings of this product
Difficult to make
Expensive materials
Time consuming
Deployment difficulty
What AxNano needed from me as an
intern
How can this product be made better?
Extended -
release
oxidation
(XRO)
product

5. MY INTERNSHIP GOALS
To design a product that;
• Less expensive : evaluating product expense
• Super-fast and easy to make: evaluating time of
completion
• Easily deployed: evaluating ease of use
• Effective in remediating contaminants: evaluating
water quality parameters like pH, ORP and
conductivity.
Hypothesis/Questions to be tested/answered with
designed products;
• Is cannister really needed?
• Is the newly designed product easier to deployed?
• Is the new design effective in remediation without
cannister?
- Does it release oxidants(percarbonate)?
5
Boundary Conditions To Note For:
-Evaluation Oxidant Release
• pH – 7 to 11
• ORP(mV) – 200 to 500
• Conductivity(mS/cm) - 0.6 to 6
-Cost
• 50% cheaper than current product
-Time to make
• 5 to 10 minutes to assemble each product
-Deployment
• 10 to 20 minutes

6. Current AxNano Product
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Sleeves (for
oxidant packing)
Cannisters
Electric wire
Ferrules

7. Product development
Overview
3 products developed
• Canisters with sleeves
• Single sleeve
• Split sleeves
Design modification
• Braided thread replaces the 2mm electric wire
• Ferrules clipper avoided
• Loops introduced for easy pull-up during
sample collection.
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Cannisters with
sleeves
Split sleeves
Single sleeves

8. Testing Product Efficiency
Designed product was tested for;
• Ease of deployment
• Effectiveness
-pH
-Conductivity
-ORP
-Control-release
Method of Testing
-Lab test of (oxidant- packed) sleeves
-Field test of (oxidant-packed) sleeves
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9. Oxidant (percarbonate)
Properties
• Odorless with white solid appearance
• Strong oxidizing properties
• Molar mass of 156.982 g/mol
• Solubility density of 150g/l
• Molecular formula Na2CO3·1.5 H2O2
Oxidizing Properties
It reacts with water to liberate H2O2
Na2CO3●1.5H2O2 (s) → Na2CO3 (aq) + 1.5H2O2 (aq)
H2O2 in groundwater remediation
In the presence of Fe(ii) salts acting as catalyst, dilute
hydrogen peroxide under mildly acidic conditions react to
initiate a very powerful oxidation process.
Fe2+ + H2O2 Fe3+ + OH- + OH●
Percarbonate
Image source: wikipedia 9

10. AxNANO Laboratory
Goal of this experiment;
- To determine release rate of hydrogen peroxide in
relation to what is to be expected from the A&T site
- to determine pH, ORP, and conductivity
of hydrogen peroxide in relation to what is to be
expected from the A&T site
What was done?
• A batch reactor was set-up labelled A-F.
• Equally measured percarbonate tablet was placed
into beaker A-C.
• Sleeves were cut up into three parts to imitate our
product design.
• Sleeves were packed with percarbonate and zip-tied
and dropped into beaker D-F (this is to show how
possible it is for percarbonate to diffuse through a
barrier when inserted in groundwater).
• Sample tests were done at different timepoints
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PC
TABLET
PC IN
SLEEVE
PC
TABLET
PC
TABLET
PC IN
SLEEVE
PC IN
SLEEVE

11. 11
Take Away From Lab Results
• There is increase in pH (becomes basic).
• There is an increased conductivity value.
• Increased oxidation-reduction potential.
• Percarbonate powder in reactor D, E, and F
was completely consumed after 1 week.
• Observed controlled release of product.
What does this mean for the designed
products?
• Product is expected to cause changes in pH,
conductivity and oxidation-reduction
potential.

12. 12
Field Deployment of
Designed Products on
A&T Farm
With lab-test background
knowledge on how designed
product is supposed to
work,
• 4 wells were chosen for
product field-test.
• Well 10, 8 , 6, and 14 were
used.
Initial Conditions of Wells
• pH was acidic on all 4
wells
• Low conductivity for all
wells
• Oxidation-reduction was
low. Area view of A&T contaminated site

13. 13
•Well 10 – control
well.​
•Well 8 – Canisters
plus sleeves.​
•Well 6 – Single sleeve​
•Well 14 – Split sleeves​
Control
(no
sleeves)
Canisters
with
sleeves Single
Sleeve
Split
Sleeves

14. 14
Field deployment of designed
products

15. 15
• pH changes from acidic to basic in wells having deployed products.
• There was a sizeable increase in conductivity ( over 300% increment).
• Oxidation-reduction potential also increased ( over 300% increment).
• All oxidants in single sleeve and split sleeves were completely consumed after 1 week, while
oxidant in canisters plus sleeves was only 95% consumed after 1 week.
RESULTS OF PRODUCT DEPLOYMENT

16. 16
GRAPH OF EFFECT OF DESIGNED-PRODUCTS ON PH

17. 17
GRAPH DEPICTING EFFECT OF DESIGNED-PRODUCTS ON OXIDATION-REDUCTION POTENTIAL

18. 18
GRAPH SHOWING EFFECT OF DESIGNED-PRODUCTS ON CONDUCTIVITY

19. 19
•Designed products were very easy
to deployed.​
•Product was easy to make​
- saves time​
- conserve energy​
- doesn't require special
technical skills​
•It was cost- effective designing
these products because;​
-ferrules, cannisters, and electric
wire was excluded in new design.
Boundaries Condition/Values Result
Control Release Yes Yes
No
ORP(mV)
Within 200-500
Yes Yes
No
Conductivity(mS/c
m). Within 0.6 - 6
Yes Yes
No
pH 7-11 Yes Yes
No
Cost; 50%
cheaper than
current product
Yes Yes
No
Time to set-
up(min)
5-10
Yes Yes
No
Easily Deployed
(10-20) mins
Yes Yes
No

20. 20
CONCLUSIONS
• Experimental results from laboratory experiment shows that percarbonate deployed in single
sleeve and split sleeves undergoes controlled release.
• Designed products allowed release of percarbonate in water to cause a positive change in pH, ORP
and conductivity.
• Single sleeve and split sleeves in well 6 and 14 respectively, were as effective as the canister
plus sleeves deployed in well 8.
• Due to invented product design (braided ropes, no canisters, and invented loops) for the A & T
experiment, samples for WM8 and WM6 were deployed easily and removed with ease for sample
collection (becomes more lighter during pull-up).

21. WHAT I THINK
• While it is noteworthy that all products deployed were
efficient, split sleeves is not advisable. They easily get
tangled during removal for sample collection, and it
consumes time in untangling these ropes.
• Based on tests and observation, I believe the single sleeve
deployment method was the best. It doesn't get tangled,
oxidants were completely consumed, and it
doesn’t require canisters.
• This design was done on a pilot-scale, design could
change or be modified for a larger scale testing.
• While single sleeve is the best based on this pilot
scale testing, its protection from tear and wear cannot be
guaranteed. Canister plus sleeves might still be better in
such scenarios.
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22. 22
RECOMMENDATIONS
• Samples collection after insertion should be done in consideration to the product size, so as
to get a clear insight on how fast percarbonate is decimated. For this product, effects of
treatment were noticeable in the results after 1 week of insertion.
• Braided ropes can be subjected to lab test to further ascertain its durability.
• Tests need to be replicated on a larger scale to account for reproducibility.

23. INTERNSHIP EXPERIENCE AND LEARNINGS
Goals set at the beginning of internship
• Learn new laboratory skills
• Expand Professional Network
• How to work as a part of a team
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24. Laboratory Skill Gained
• I gained super helpful skills like
-writing and editing SOPs
-following SOPs
-batch reactor set-up
-pipetting
• I know mechanism behind some oxidants reaction by performing experiments on
-water quality
-percarbonate/hydrogen peroxide assay
-persulfate assay
• Mastered the use of lab equipment such as pH, conductivity, and ORP meter.
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25. Expand Professional Network
Working at AxNano has opened the opportunity to know;
The CEO, Doug Speight – was able to learn how business can be integrated
into research.
The Chief Scientist, Alexis Carpenter- learned how to assigned and monitor tasks.
The research manager, Julia Darcy- was very helpful in helping me developed my
research skills and answering most of my questions.
The research assistant, Laura Grace- super helpful with the batch reactor
experiment. I was able to integrate easily.
The assistant scientist, Ryan Rains – Learned a lot of life saving skills from him. His
skills were super helpful on the field. I knew more coffee shops through him.
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26. How To Be A Team Member
Over five months at AxNano has taught me that working as part of a team is necessary for personal
development as well as professional development.
What I learned
• Working as a team improve team bonding, case study, the Monday team bonding meeting spear-headed
by Laura Grace.
• Works get completed faster and efficiently.
-working on algae bloom with Julia and the team.
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27. ACKNOWLEDGEMENT
Special thanks to all staffs of AxNano for the opportunity afforded me to do my internship in this organization.
Special thanks to the CEO,Doug Speight, and my supervisor, Alexis Carpenter for providing an enabling
environment to set and achieve my internship goals.
Special thanks to Julia and Laura for the patience in answering my questions, and the support provided during
my lab operations.
Special thanks to Ryan for taking that weekly trip with me to collect data. I appreciate you.
And lastly, special thanks to my advisor, Dr. Herr, for the understanding, and the advice.
God bless you all.
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