Grantee Research Project Results
2021 Progress Report: Development of Reactive Nanobubble Systems for Efficient and Scalable Harmful Algae and Cyanotoxin Removal
EPA Grant Number: SV840019Title: Development of Reactive Nanobubble Systems for Efficient and Scalable Harmful Algae and Cyanotoxin Removal
Investigators: Zhang, Wen , Shi, Xiaonan , Zhang, Yihan , Gardazi, Syed
Current Investigators: Zhang, Wen
Institution: New Jersey Institute of Technology
EPA Project Officer: Aja, Hayley
Phase: II
Project Period: July 1, 2020 through June 30, 2022
Project Period Covered by this Report: July 1, 2020 through June 30,2021
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2020) Recipients Lists
Research Category: P3 Awards
Objective:
Objective 1: Evaluation of the colloidal stability of ozone NBs under different levels of temperature, pH, and salinity.
Objective 2: Characterization of reactivity of ozone NBs in water suspension.
Objective 3: Assessment of micropollutant degradation and disinfection using O2/O3 NBs.
Progress Summary:
Task 1. Validation of the measurement methods for the aqueous ozone concentration. In the pursuit of generating high-quality and consistent ozone NBs in water, we evaluated the three common ozone detection methods to measure the aqueous phase ozone concentration, namely, the Indigo method, the KI method, and the electrochemical sensor method using a DO3 Meter. First, the ozone saturated water was prepared by injecting ozone gas generated by a MP-5000 ozone generator (A2Z Ozone, USA) with the ultrapure oxygen as the feed gas (5 psi, 1.15 LPM, and 20 0C), which generated approximately 5 g·h-1 according to the manufacturer’s manual. The 1-L DI water was purged by the ozone gas for 1 h. Thus, the ozone concentration may reach up to 5000 mg·L-1 if no ozone lost due to evaporation, which in fact will occur. Moreover, ozone has a decay rate constant of 15.7 h-1 and undergo fast decay in water, which all result in a relatively lower concentration than 5000 mg·L-1. The measured concentrations by the three methods were not identical probably due to the different detection principles. Three levels were reached at 178.2±4.8, 89.6±4.5, and 29.7±1.3 mg·L-1 respectively, which confirmed our above speculation. We adopted the result from the Indigo method in all future tests that is more reportedly used in literature. To estimate the ozone transformation or conversion rate with the MP-5000 ozone generator, the feed oxygen gas was injected to the generator under different pressures (5 psi, 3 psi, 1 psi) and a gas flow rate of 1.15 LPM. We evaluated the dynamics of ozone concentration over time. The ozone concentration increased faster under higher injection pressures and reached a plateau level of 207.1±5.7, 166.7±4.9, 163.1±4.8 mg⸳L-1, which depends on the corresponding ozone partial pressure in the produced mixture gas of O3/O2.
Task 2. Antimicrobial assessment (e.g., biofilm prevention). As one of the important environmental applications of ozonation, the potency of biofilm prevention by ozone NBs has been initially characterized and evaluated in a customized microfluidic cell in Fig. 2a, where bacteria were spiked in the buffer solution to flow into the cell via the light blue tubular port. Biofilm growth on the substrate surfaces induces a change in the electrical characteristics in both the surround medium and the interface of the solid substrate surface.1 To characterize these changes, the electrochemical impedance (EIS) measurements was conducted by the CHI electrochemical workstation in a frequency range of 0.316-106 Hz with a gold coated electrode (18-22AWG CRIMP GOLD) and a stainless steel plate (an exposure areas: 1.2 cm×1.0 cm) as the counter electrode (CE) and the work electrode (WE) respectively. The impedance of the fluidic environment between WE and CE in the microfluidic channel was monitored versus time to indicate the surface deposition of bacteria or biofilm formation.
Fig. 2. A microfluidic device that measures the EIS on the biofilm growing surface (working electrode or WE). The photo shows the microfluidic device developed in Dr. Wen Zhang’s laboratory at NJIT.
Future Activities:
Task 1: Characterization and differentiation of ozone bubble and dissolved ozone concentrations
Task 2: Evaluation of radical species generation in the water of ozone NBs and Electrochemical characterization of ozone NBs.
Task 3: Assessment of the interfacial bacterial deposition rates in the presence of O2/O3 NBs
Journal Articles on this Report : 5 Displayed | Download in RIS Format
| Other project views: | All 24 publications | 9 publications in selected types | All 7 journal articles |
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Ahmed AK, Sun C, Hua L, Zhang Z, Zhang Y, Zhang W, Marhaba T. Generation of nanobubbles by ceramic membrane filters:The dependence of bubble size and zeta potential on surface coating, pore size and injected gas pressure. Chemosphere 2018;203:327-355 |
SV840019 (2021) SU839451 (Final) |
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Shi X, Qing W, Marhaba T, Zhang W. Atomic Force Microscopy-Scanning Electrochemical Microscopy for Nanoscale Topographical and Electrochemical Characterization:Principles, Applications and Perspectives. Electrochimica Acta 2019;14:135472. |
SV840019 (2021) SU839451 (Final) |
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Wang S, Liu Y, Li P, Wang Y, Yang J, Zhang W. Micro-nanobubble aeration promotes senescence of submerged macrophytes with low total antioxidant capacity in urban landscape water. Environmental Science:Water Research & Technology 2020;6(3):523-31. |
SV840019 (2021) |
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Shi X, Xue S, Marhaba T, Zhang W. Probing Internal Pressures and Long-Term Stability of Nanobubbles in Water. Langmuir 2021 ;37(7):2514-22. |
SV840019 (2021) SV840019 (Final) |
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Patel AK, Singhania RR, Albarico FPJB, Pandey A, Chen, CW, Dong CD. Organic wastes bioremediation and its changing prospects. SCIENCE OF THE TOTAL ENVIRONMENT 2022;824:153889. |
SV840019 (2021) |
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Supplemental Keywords:
Ozone nanobubble, generator evaluation, colloidal stability, reactivity characterization, biofilm prevention.Relevant Websites:
Progress and Final Reports:
Original AbstractP3 Phase I:
Reactive Nanobubble for Algae and Cyanotoxin Removal | 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.