Grantee Research Project Results
3D-Printed Floating Photocatalyst Structures that Mimic Natural Objects to Combat Harmful Algal Blooms
EPA Grant Number: SU840864Title: 3D-Printed Floating Photocatalyst Structures that Mimic Natural Objects to Combat Harmful Algal Blooms
Investigators: Rao, Pratap , Akkaya, Ceren Yilmaz , Nemitz, Markus
Institution: Worcester Polytechnic Institute
EPA Project Officer: Page, Angela
Phase: I
Project Period: February 1, 2024 through January 31, 2026
Project Amount: $74,881
RFA: 20th Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet Request for Applications (RFA) (2023) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
Description:
Harmful algal blooms (HABs) caused by excessive growth of various algae have become a major concern for inland water safety across the United States. HAB related contamination threatens plant and wildlife - as well as contributes to economic loss due to increased health-related costs, water-treatment costs, and unemployment.
Our project will develop 3D-printed floating structures coated with photocatalysts, which can be deployed into water bodies to combat cyanobacteria-dominated harmful algal blooms such as those that occur frequently in Indian Lake in Worcester, MA. Photocatalysts have been shown to break down the cyanobacteria and associated toxins. The 3D-printed floating structures that carry the photocatalysts will mimic the appearance of locally-occurring natural objects (leaves, branches, etc) so that they do not deter the local wildlife. The structures can be deployed by a swimming robot to combat the HABs and then retrieved again by the same robot, so that they do not leave any lasting impact on the natural environment.
Objective:
A sustainable and affordable strategy to treat HABs is degradation of cyanobacteria by sunlight-driven photocatalysts. A long-standing barrier to wide-spread utilization of photocatalysts for water treatment is their collateral impact on the ecosystem due to the challenges in their deterring effect on local wildlife and their recovery from the water bodies. This research will investigate modified 3D printing processes for fabrication of deployable and recoverable floating structures that breaks this barrier. Our research objective is to design and fabricate 3D-printed floating systems which 1) have high specific surface area for high efficiency, 2) are coated with a fully exposed, uniform layer of photocatalyst on the surface for high number of exposed active sites, 3) are intentionally designed to be in the shape of locally-occurring natural objects that do not deter local wildlife, 4) can breakdown cyanobacteria, 5) can be quickly deployed at the site-of-concern, and 6) can be retrieved by swimming robots and reused when/where needed.
If successful, our goal is to extend our project for field testing of the floating 3D-printed photocatalyst structures to combat HAB blooms in Indian Lake, Worcester MA. The developed systems will ensure quick on-demand response to HAB events in Worcester and beyond, which is important for many states, tribes, and territories that do not have formal HAB monitoring and treatment programs for surface waters.
Approach:
The work in this proposal will focus on i) designing and 3D printing structures that float, mimic natural objects, and provide a high surface area and good access to sunlight for the photocatalyst particles, ii) developing a coating approach that allows the photocatalyst particles to be uniformly coated over the surface of the 3D-printed structures with good adhesion to the structure and good contact with the water, and iii) testing the resulting 3D printed structures functionalized with photocatalysts for efficacy in the application of breaking down cyanobacteria in a laboratory setting, including testing of the durability of the photocatalysts and evaluation of any potential leaching or toxicity. Our project synergistically combines environmentally conscious design with laboratory scale development and demonstration to ensure safe access to the ambient water bodies by our community. This project will also provide hands-on laboratory training for the undergraduate students in Mechanical Engineering and Robotics Engineering. The undergraduate students will work together with graduate students to enhance their technical skills on 3D printing technology, photocatalysis, coating processes, and microbiology techniques. The graduate students will gain the capacity for inclusive mentoring of next generation engineers. In line with Worcester Polytechnic Institute's values based on "Purpose Driven Research" and "Inclusive Community," our students will address a real-world problem that is affecting their local community. The student team will also develop hands-on activities targeted towards K-12 students based on the proposed project. Performing these activities with K-12 students from underserved and underrepresented local groups, will provide our students with opportunities for improving their self-confidence, communication skills, and leadership while educating the wider community on the social, medical, and economic impacts of HABs, and innovative water treatment technologies.
Expected Results:
The expected research outcome is an innovative, effective, sustainable, and eco-friendly HAB management tool that can be deployed rapidly when urgent response is needed. Worcester is the second largest city in New England and has a 47% population identifying as an underrepresented group, and 19.3% are persons in poverty. These groups heavily rely on the free local water bodies for recreation. Development of the proposed systems will improve health and well-being of these groups. The performance of the floating 3D-printed photocatalyst structures will be evaluated by utilizing simulated sunlight to measure the efficiency of the systems on degrading cyanobacteria in simulated lake water. Reusability of the system, stability of the photocatalyst, and any potential leaching will also be considered in final evaluation of the system effectiveness. The prototypes will be showcased at the 2025 EPA P3 National Sustainable Design Expo together with videos of the system in action. The student team will also incorporate their research into K-12 outreach efforts educating the wider Worcester community on the impacts of HABs, and innovative water treatment technologies. The proposed innovative rapid response technology for combatting HABs will further pollution control efforts since site-specific HABs have shown to degrade water quality to a greater extent than many chemical pollutants.
Supplemental Keywords:
Design for the environment, inland waters, urban water safety, clean water technologies, disinfection, pathogen removal, fused deposition modelling (FDM)The 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.