Research Interest
Environmental Implication and Application of Carbonaceous Nanomaterials
The environmental impact of fullerenes, both C60 and carbon nanotube (CNT), is of great concern due to projections for wide spread application and bulk production in near future. Recent discoveries that C60 forms nano-scale water-stable aggregates upon release to water and that CNT forms stable aggregates with natural organic matter have redefined our view on their environmental impact as potential water contaminants. Our group studies dispersion characteristics of fullerenes in natural water, their interaction with natural water constituents, and their chemical (e.g. ozone and radicals) and photochemical reactivity. Our more current research involves application of fullerene's phototochemical reactivity for application in water treatment.
High-Pressure Membrane Processes for Emerging Contaminant Treatment
Our group studies transport mechanism of several emerging water contaminants through nanofiltration and reverse osmosis membranes with the ultimate goal of better designing the membrane processes for effective water reclamation and reuse. Contaminants of interest include hormone such as 17beta-estradiol, selected human and veterinary antibiotics, such as sulfamethoxazole, trimethoprim, erythromycin, ciprofloxacin, and carbadox, various nitrosamines disinfection by-products and their precursors, boron in seawater and engineered nanomaterials.
Ozone Disinfection Process Design and Optimization
Optimizing ozone disinfection processes to provide adequate inactivation of Cryptosporidium parvum oocysts (i.e., the pathogen with the greatest resistance to chemical disinfectants) with minimum production of disinfection by-products such as bromate has been very challenging to many water treatment utilities. We use a computer simulation, full-scale field testing, and laboratory experiments to develop a better design tool for ozone disinfection processes. Recently, we have been developing 3-dimensional laser induced fluorescence technique to visualize and quantify the mixing conditions in ozone reactors and UV disinfection reactors.
Solving Real World Engineering Problems
Our group has been involved in various real world projects as demanded by local governments, utilities, and engineering companies. For example, we studied the problem of unexpectedly low monochloramine stability in the water treatment facility of the City of Tampa, FL and successfully provided a solution that immediately impacted current treatment practices. In another project, a novel emulsion liquid membrane process to treat organic and metallic contaminants from industrial wastewater was developed. We also have investigated water quality in the Gwinnett County distribution system networks through model simulation as well as field sampling and laboratory experiments. More recently, we focus on novel disinfection and water treatment technologies based on membrane processes and novel catalyst materials for application in developing world.
Research Projects
1. M/DBP Model for the Optimization of Full-Scale Process Design and Operation: Enhancing the Ozone Contactor Simulation Software, US Environmental Protection Agency, subcontract under University of Illinois at Urbana-Champaign, 2004
2. Lanier Filter Plant Treatment Process and Distribution System Study, Gwinnett County Public Utilities, Gwinnett County, GA, Co-PI: James Amburgey, 2004-2005
3. Water Quality and Treatment Process Study II. Evaluation and Assessment of Biological GAC filters at the DLT Water Treatment Plant of Tampa City, City of Tampa, FL. Subcontract under Black & Veatch, 2004-2006
4. Water Quality and Treatment Process Study I. Understanding the fate of organic matter at the DLT Water Treatment Plant of Tampa City, City of Tampa, FL. Subcontract under Gannett Fleming, as Co-PI, PI: Michael Perdue, 2004-2006
5. Removal of Emerging Trace Organic Contaminants in Surface Water by Ultrafiltration and Nanofiltration, Saehan Industries, Inc., Co-PI: Ching-Hua Huang, 2004-2005
6. Boron Rejection by Reverse Osmosis Membranes: National Reconnaissance and Mechanism Study – Phase I., Bureau of Reclamation, US Department of Interior, 2004-2006
7. Heavy Metal And Ionic Species Removal From Phosphoric Acid Solutions: Phase I – Emulsion Liquid Membrane, Tata Chemicals, Ltd., 2005-2006
8. A Computer-Based Design of New Ozone Contactor Treating Paldang Dam Reservoir Water, Shinwoo Engineering, 2005
9. Fate and Transformation of C60 Nanoparticles in Water Treatment Processes, US Environmental Protection Agency Science to Achieve Results (STAR) Grant, Co-PI: Joseph Hughes, 2005-2008
10. Optimization of Ozone Contactor Design and Operation Parameters through Laser Induced Fluorescence, Hankuk Engineering, Co., LTD., Co-PI: Philip Roberts, 2006-2007
11. Investigating Mixing in Baffled Ozone Contactors Using 3-D Laser Induced Fluorescence and Reactive Transport Model, US Environmental Protection Agency, Co-PI: Philip Roberts, 2006-2007
12. Design, Construction, and Feasibility Testing of a Computer-Automated Remote-Controlled Pilot-Scale Drinking Water Treatment System & Practical Application of a Distribution System Model, Gwinnett County, GA, 2007-2008
13. Visualization and Quantification of UV Dose and Mixing in UV Reactors by 3D Laser-Induced Fluorescence, American Water Works Association Research Foundation Unsolicited Program, Co-PI: Philip Roberts, Thorsten Stoesser, Harold Wright, and Kyunghyuck Lee, 2007-2009
14. Removal of Emerging Contaminants by Reverse Osmosis Membranes, Korean Ministry of Construction and Transportation, Subcontracted Under Korea University, 2007-2012
15. Development of Automation Control System for Sequential Disinfection Processes, Korean Ministry of Environment, 2008-2011
16. Developing a Novel Membrane Pore Size Analysis Technique Using Quantum Dots, Korea Institute of Industry Technology, 2008-2009
17. Evaluation of Computational Fluid Dynamics Modeling Approaches Applied to Ozone Contactor Design, USEPA, PI: Thorsten Stoesser, Co-PI: Jaehong Kim, 2009-2010
18. Laboratory and Field Scale Evaluation of the Homespring Central Water Purifier, GE Foundation, Co-PI: Kevin Caravati and Joseph Hughes, 2009.
19. Boron Rejection Simulation In Full-Scale Seawater Reverse Osmosis Systems, GS Construction & Engineering, 2009-2011
20. Coagulation-Ceramic Membrane Filtration Processes for U.S. Surface Water Treatment: the Effect of Coagulation and Membrane Fouling, Water Research Foundation, 2010-2011
21. Developing Novel Surface Immobilized Photocatalysts Using Functionalized C60, National Science Foundation, 2010-2012