Grantee Research Project Results
Final Report: A Biopolymer-based Simple Lead Check in Tap Water
EPA Grant Number: SU839458Title: A Biopolymer-based Simple Lead Check in Tap Water
Investigators: Lee, Woo Hyoung , Cho, Hyoung Jin , Hwang, Jae-Hoon , Rodriguez, Kelsey , Bal, John , Davis, Rebekah
Institution: University of Central Florida
EPA Project Officer: Page, Angela
Phase: I
Project Period: November 1, 2018 through October 31, 2019
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2018) RFA Text | Recipients Lists
Research Category: P3 Challenge Area - Safe and Sustainable Water Resources , P3 Awards
Objective:
The proposed research project is to advance the technology currently used to determine trace levels of Lead (Pb) in tap water samples, on site. Lead is one of the most monitored heavy metals due to its high toxicity and commonality in water. Even in small concentrations, as often found, lead is an extreme concern to human health, as recognized by the EPA's Safe Drinking Water Act action level of 0.015 mg/L (15 ppb). The concern for lead contamination, on a global scale, has led to the desire of an analytical method that can rapidly determine trace levels. The motivation of this research is to develop an electrochemical biopolymer-modified carbon screen-printed sensor that can determine trace levels of lead at the terminal plumbing source, such as faucets. This innovative approach is intended to modify the well-acquainted mercury-based ex situ sensor. Currently, methods used to determine lead concentrations require transportation of the desired sample to a laboratory, trained personnel, and the use of mercury: a highly toxic, non-biodegradable heavy metal. This research aims to overcome such limitations by utilizing chitosan: a natural, low-cost, biopolymer, and alternate to mercury. The proposed carbon screen-printed aspect allows for a sensor that can be used under time and locational constraints. The ability to modify a screen- printed sensor allows for target object specifications to be met at a low-cost, highly- reproducible rate. The research objectives of this study are to: (1) design and develop an in situ electrochemical chitosan-modified carbon screen-printed sensor; and (2) characterize and evaluate optimal conditions for sensor performance for in situ lead detection. The chitosan- modified sensor will allow a positive impact for the planet due to its disuse of mercury. When polluted in bodies of water, mercury bioaccumulates in the soft tissues of animals and fish. Many wildlife that consume these contaminated organisms are at concern for health risks. These risks include reproductive problems, liver and kidney damage, and neurobehavioral changes. Similarly, mercury is toxic for people. Any disuse of mercury will help reduce the amount of contamination and thus potential health risks to humans. As well, this approach to fabricating a sensor will allow for rapid and convenient determination of trace levels of lead. Lead is a toxic pollutant that can be found in drinking water, as common as that from household plumbing sources. Having a sensor that can detect lead contamination can prevent severe human health risks. This in situ design extends to economic prosperity as use of electrochemical methods are low-cost, simple, and portable compared to conventional analytical methods. Overall, the development of a chitosan-modified carbon sensor has the great potential for a sustainable approach to lead control in drinking water. In addition, this research has the potential to inform those in academia and in the community about the innovative approach to the design and necessity of lead detection due to the health risks associated. A presentation of the results of this P3 project will be addressed and shared with UCF's chapter of Engineers without Borders (EWB) and Society of Environmental Engineers (SEE), which will also be open to the rest of the community.
Summary/Accomplishments (Outputs/Outcomes):
Results from this project successfully displayed a simple and rapid lead detection in drinking water environment. Biopolymer-modified carbon electrode sensors were fabricated using a screen-printing technique followed by drop casting. From the analysis using Fourier Transform Infrared (FTIR) spectra, the presence of O–H, C–H, C=O, N–H, CH–OH, and CH2–OH functional groups in the fabricated electrode was found, indicating that chitosan was effectively deposited on the carbon electrode. With the optimized analytical parameters (300 s deposition time, -1.2V deposition potential, 0.004 V potential step, 0.025 V amplitude, and 20 Hz frequency), the SWASV responses showed the well-defined sharp peaks toward different concentrations of lead (Pb2+). It was found that the pH effect on the change of heavy metal ions concentrations is due to the intrinsic metal ionic phenomena in water and pH itself is not an interfering parameter in terms of sensor sensitivity and operations. In the rage of temperature between 4 and 25 oC (cold and room temperature), the temperature effect on lead detection minimal with low signal variation less than 2%. For the reproducibility test, the sensor displayed an excellent reproducibility (n=30) with relative standard deviation (RSD) of 5.4%. This is the great achievement given that the previous studies had at most 15 times measurements. Finally, the developed chitosan applied to a real tap water environment with spiked lead concentrations. The application results showed that the biopolymer-coated carbon electrode is reliable and suitable for sensitive and selective determination of Pb2+ in a drinking water environment.
A comparison of actual accomplishments with the anticipated objectives (outputs/outcomes) specified in the original proposal is shown in the table below.
Objectives in original proposal | Acual accomplishments | Achieve % | ||
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Technical | Design and develop an in situ electrochemical chitosan-modified carbon screen-printed sensor | Design of a carbon screen-printed sensor | ✓ Metal mesh screens were designed using AutoCad -> The electrodes were printed in three layers (silver, carbon, and insulating layers) using a designated mesh screen | 100 |
Biopolymer composite film development by drop casting and characterization of fabricated chitosan film | ✓ Chitosan composite film formation using drop casings | 100 | ||
Characterize and evaluate operating parameters for optimal sensor performance | Optimization of SWASV parameters | ✓Determined optimal current outputs and peak shapes for detecting Pb2+ ion by SWASV (deposition time, amplitude and freqency) ✓To evaluate the effect of pH and temperature on Pb2+ detection | 100 | |
Investigation of pH and temperature effects | 100 | |||
Reproducibility test | ✓ Repetitive SWASV response measurements for 10ppb of Pb2+ion ✓ Evaluated sensor performance in a real wastewater environment | 100 | ||
Application to a tap water | 100 | |||
Outreach and Education | Incorporate research results in education, training, and outreach | ✓ Incorporated research results in undergraduate and graduate courses taught by PI (Env. Eng) and Co-PI (Mech.Eng) ✓ 1 peer-reviewed journal publication (Electrochimica Acta) ✓ 2 manuscripts preparation ✓ 4 conference presentations including UCF's Showcase of Undergraduate Research Excellence (SURE( ✓ 2 educational conference presentations (ASEE and ACS) ✓ Selected as a Judge's Choice Winner (Student and leader) in 2018 SURE ✓ One provisiional application ✓ Involvement in STEM activities (an existing NSF RET) | 100 |
Overall, Phase I project found that 1) biopolymer (e.g., chitosan) had greatly improved the lead detection sensitivity, 2) expanded the reproducibility compared to previous similar technologies for lead detection, and 3) applied to a real tap water environment without any other interference. The sustainable aspects of this project come from its specific and careful consideration of the people, prosperity, and planet (P3). The biopolymer-coated sensor can prevent further contamination of heavy metal ions due to its direct monitoring application. Furthermore, the low-cost, user-friendly, and highly-efficient design of the Biopolymer-coated microsensor allows it to be economically feasible for commercial use, contributing to prosperity. These considerations focusing on people, prosperity, and planet contribute to the advancement of global sustainability practices that will ensure the protection and conservation of natural resources for generations to come in a rapidly developing world.
Conclusions:
Heavy metal ions, especially Pb2+, have long been an enormous environmental and health issue that can cause harmful effects. Current and traditional methods are labor-intensive, cost-inefficient, and tend to introduce additional contaminants and chemicals (for analysis) into an impacted area which can lead to detrimental impacts in the future. We expect that the developed biopolymer-coated microsensor will detect trace levels of lead in homes (reagentless) to check for lead in tap water. An on-site sensor with quick detection times can provide a simple way to prevent lead consumption and prevent possible health risks. Through the objectives outlined in Phase I, we have demonstrated a new biopolymer sensor fabrication design, characterization of the sensor for SWASV, reproducibility and repeatability for Pb2+ detection under different temperature and pH conditions, and Pb2+ detection in real application (tap water). The biopolymer-coated sensor exhibited excellent detection performance including good selectivity, sensitivity, and reproducibility under contaminated sample. Our simple sensor design of the biopolymer-coated planar screen-printed carbon electrode could save labor and operation time and analysis cost compared to the sophisticated equipment. Particularly, the low resource demands and labor costs means that the chitosan-coated sensor would have potential as a simple Pb2+ check in homes. Encouraged by the successful proof-of-concept demonstration of the biopolymer-coated microsensor accomplished in Phase I period, we will extend our works extensively in Phase II for optimization of the sensor technology, and development of prototype of the portable sensor system, LCA, and business model/customer development.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 8 publications | 3 publications in selected types | All 3 journal articles |
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Type | Citation | ||
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Hwang JH, Pathak P, Wang X, Rodriguez KL, Cho HJ, Lee WH. A Novel Bismuth-Chitosan Nanocomposite Sensor for Simultaneous Detection of Pb (II), Cd (II) and Zn (II) in Wastewater. Micromachines 2019;10(8):511. |
SU839458 (Final) SV840021 (2021) |
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Hwang JH, Islam MA, Choi H, Ko TJ, Rodriguez KL, Chung HS, Jung Y, Lee WH. Improving Electrochemical Pb2+ Detection Using a Vertically Aligned 2D MoS2 Nanofilm. Analytical chemistry 2019;91(18):11770-7. |
SU839458 (Final) SU839263 (Final) SV840021 (2021) |
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Hwang JH, Wang X, Zhao D, Rex MM, Cho HJ, Lee WH. A novel nanoporous bismuth electrode sensor for in situ heavy metal detection. Electrochimica Acta 2019;(1)298:440-8. |
SU839458 (Final) SV840021 (2021) |
Exit Exit |
Supplemental Keywords:
Biopolymer, Electrochemical sensors, Environmental monitoring, Heavy metal detection, Screen-printed carbon electrode, Square wave anodic stripping voltammetry (SWASV)Relevant Websites:
CECE Student Projects Receive Two Awards from U.S. Environmental Protection Agency Exit
P3 Phase II:
A Biopolymer-based Simple Lead Check in Tap Water | 2021 Progress Report | 2022 Progress Report | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.