Research Highlights

My research interests are in the broad area of Environmental Chemistry in the water sphere. Specifically, my group has been active in several research areas including emerging contaminants, contaminant transformation kinetics and mechanisms, advanced analytical techniques, and novel physical-chemical treatment processes for water and waste systems. We have investigated a wide range of contaminants, including pharmaceuticals and personal care products (PPCPs), emerging disinfection by-products (DBPs), nanomaterials, and toxic heavy metals, for their occurrence, fate, and remediation in natural aquatic systems and engineered treatment processes. The goal of my research effort is to advance our fundamental understanding of reaction kinetics and mechanisms which are imperative to improve characterization and prediction of the environmental fate of contaminants, and serve as the foundation to enhance development of novel treatment technologies to mitigate contaminants.

Current active reseach areas include:

 

CURRENT RESEARCH PROJECTS:

Water treatment technologies and processes

  • 2016-2021, Peroxy acids as emerging disinfectants for water treatment: Oxidation chemistry elucidation and optimization. (PI)

   

Peroxy acids (POAs), such as peracetic acid and performic acid, are emerging disinfectants/oxidants to replace chlorine in wastewater and storm water treatment. Compared to chlorine, the major benefits of POAs are their high effectiveness in disinfection and minimum formation of harmful byproducts. Furthermore, activated POAs by UV irradiation or catalysts are novel advanced oxidation processes that can be useful for degrading recalcitrant organic micropollutants in water. However, even with increased industrial usage of POAs, fundamental research of POAs trails behind their applications. This research project is led by Prof. Ching-Hua Huang to investigate the fundamental reaction kinetics and mechanisms of POAs and activated POAs for their applications in water treatment. The goal is to create the knowledge base that will be useful for improvement and optimization of the POA and UV/POA technology. 

 

  • 2018-2021, Ferrates oxidation for mitigation of pharmaceutical micropollutants in source-separated urine: Underlying mechanisms. (PI)

Human urine accounts for <1% of domestic wastewater by volume yet urine contributes a disproportionate mass load of nutrients and pharmaceuticals to wastewater. While intensifying nutrient recovery in diverted urine has been proposed as a more sustainable alternative to conventional wastewater management, eliminating pharmaceutical micropollutants from the urine will also be highly beneficial. This project will develop a ferrate-based advanced oxidation technology (AOT) that is particularly promising for treating pharmaceuticals and their metabolites in the challenging urine matrices. Effective destruction of pharmaceuticals in urine can minimize energy-intensive treatment required at centralized wastewater facilities to remove these micropollutants, and reduce their potential harm to receiving waters and drinking water sources. This project will be led by Prof. Ching-Hua Huang at Georgia Tech and in collaboration with Profs. Virender Sharma and Leslie Cizmas at Texas A&M to elucidate the fundamental mechanisms of ferrate-based AOT and optimize the treatment efficiency in pollutant and toxicity reduction.

(https://www.youtube.com/watch?v=Ts_9ffLnV1c&index=18&list=PLjDJ5jMy4gFY71nPASWgb7avXIgJzMqhU)

 

  • 2018-2021, Biochar-catalyzed microbial reductive degradation of emerging organohalides. (Co-PI)

 

 

Environmental fate and transformation of emerging contaminants

  • 2020-2021, Per-/Polyfluoroalkyl Substances in Wastewater Treatment Plants (PI)
  • 2018-2019, Environmental chemistry of micropollutants in soil solid/liquid/gas interfaces. (Co-PI)
  • 2017-2019, Antibiotic resistance in concentrated poultry feeding operations: Impacts on environmental waters. (Co-PI)

 

 

INFEWS and Food Safety

  • 2014-2019, Development and transfer of disinfection by-products into fresh and fresh-cut produce and impact on disinfection efficacy. (PI)

Chlorine-containing disinfectants are widely used in the processing of fresh and fresh-cut produce. However, significant knowledge gaps still exist regarding the formation, identities and quantities of disinfection by-products (DBPs) generated as food residues or in the processing water. This project addresses this issue by investigating many conventional and emerging DBPs of concern for their mechanisms of formation and transfer into fresh and fresh-cut produce after chlorine-based disinfection methods, and for their impact on the efficacy in inactivating pathogens. The overall goal is to obtain a more comprehensive understanding of the formation mechanisms and to develop effective disinfection strategies of high microbial inactivation efficacy and minimized DBP formation for fresh and fresh-cut produce.

 

  • 2018-2022, Use of domestic wastewater for food production. (Co-PI)

 

  • 2017-2020, Closing the loop: An integrated, tunable, and sustainable management system for improved energy, nutrient, and water recovery from biowastes. (Senior Personnel)

 

 

Energy production wastes pollution control and resource recovery

  • 2017-2021, Recoery of rare earth elements from coal fly ashes using novel extraction methods. (PI)
  • 2016-2019, Mineralogy optimization for immobilization of heavy metals in co-disposed flue-gas-desulfurization brines and bituminous coal fly ash. (PI)

The coal-fired power industry faces increasing demands to improve coal fly ash (CFA) and flue gas desulfurization (FGD) wastewater disposal practices. The zero liquid discharge (ZLD) options for FGD wastewater are attractive but the ZLD residuals present new challenge for the solid waste industry due to significant concentrations of mobile heavy metals and chloride. We have developed a novel ZLD method by coupling brine concentration with a solidification/stabilization (S/S) process through co-disposing FGD brine with CFA and a pozzolanic agent. The immobilization of oxyanions (particularly Se(VI)) and chloride by S/S of concentrated FGD brines and CFA from bituminous coal plants is most challenging. Thus, this project aims to optimize the immobilization of Se(VI) and chloride in the co-disposed concentrated FGD brines and bituminous CFA (BCFA) by S/S.

 

 

 

PAST RESEARCH PROJECTS:

Water treatment technologies and processes

  • 2016-2017, Direct and indirect potable water reuse assessment. (Co-PI)
  • 2014-2015, Efficacy of advanced oxidation processes for disinfection of biological contaminants of emerging concern (PI)
  • 2014-2015, Granular activated carbon biofiltration optimization for drinking water treatment (Co-PI)
  • 2011-2012, Integrating carbon dioxide sequestration, renewable bioenergy production and wastewater treatment using microalgae (Co-PI)
  • 2010-2013, Transformation of amines to nitrosamines on activated carbons (PI)
  • 2009-2011, Occurrence survey of pharmaceuticals and personal care products (PPCPs) in source water, drinking water, and raw and treated wastewater (PI)
  • 2006-2007, Role of anaerobic digestion in N-nitrosodimethylamine (NDMA) formation in municipal wastewater treatment Plants: Source or sink. (Co-PI)
  • 2005-2006, Point source ozonation to minimize antibiotic resistance. (Co-PI)
  • 2004-2010, Potential N-nitrosodimethylamine (NDMA) formation from water and wastewater treatment polymers (Co-PI)
  • 2004-2007, Removal of pharmaceuticals, N-nitrosamines and precursors by reverse osmosis and nanofiltration membranes. (Co-PI)
  • 2002-2003, Chlorination and ozonation of antibiotics detected in Georgia waters. (PI)
  • 2000-2002, Occurrence survey of pharmaceutically active compounds in the environment. (Co-PI)
  • 2000, Analysis of estrogenic hormones in municipal wastewater effluent and surface water. (PI)

 

Environmental fate and transformation of emerging contaminants

  • 2009-2014, Fate of antibiotics in poultry litter before and after application to grasslands. (PI)
  • 2002-2006, Elucidating the oxidative transformation of antimicrobial agents with Mn, Fe and Al oxides (PI)

 

INFEWS and Food Safety

  • 2016, Peracetic acid sanitizer for fresh produce processing - Disinfection byproduct evaluation. (PI)

 

Energy production wastes pollution control and resource recovery

  • 2015-2017, Combined iron reduction and solidification/stabilization process to immobilize heavy metals in concentrated flue gas desulfurization brines. (PI)
  • 2013-2015, Immobilization of heavy metals in co-disposed coal fly ash and concentrated FGD wastewater brines using solidification/stabilization.  (PI)