We have been utilizing the principles of environmental biogeochemistry, interfacial chemistry and microbiology to resolve various environmental problems and to come up with economically feasible biofuels.
Our lab research works have been primarily on 1) Bioenergy production using various biomass sources, and 2) Biogeochemistry of metals and (in)organic pollutants in natural and engineered environments. Regarding the bioenergy research, we have shown that microalgae cultivation can be coupled with advanced wastewater treatment so that both higher removal of N, P from domestic wastewater and massive cultivation of microalgal biomass are achieved which might increase the economic feasibility of bioenergy production (biohydrogen, bioethanol, biobutanol and biodiesel) with a simultaneous improvement of treated water quality.
Another research interest on bioenergy production is co-digestion of sludge (produced from domestic wastewater treatment plant) with food waste which contains significant amount of fat, oil and grease (FOG). The focus of this research is to come up with an anaerobic microbial consortium which is capable of efficient degradation of long chain fatty acids (FOG) to short chain fatty acids. The final goal of this study is to enhance methane production through co-digestion of various biomasses with sewage sludge for better economic feasibility through the application of FOG degrading microbial consortium. Co-digestion of sewage sludge and technology advances in biogas industry might help to convince the government, research institute and industry to boost up the biogas business in S. Korea.
We have been also working on biogeochemistry of numerous (in)organic contaminants primarily in the natural environment, and occasionally in the engineered system. Our interfacial chemistry work stemmed from the careful investigation of reactions between Fe(II) and Fe(III) oxides where we observed interfacial electron transfer from sorbed Fe(II) to structural Fe(III) in Fe(III) oxides. Such interfacial electron transfer between sorbed metal atom and structural metal atom help us to conduct more careful studies on the sorption of U(VI) and Tc(VII) and subsequent reduction in the presence of Fe(II) ion in aqueous phase which will control the fate and mobility of such environmentally significant pollutants. Extending such interfacial chemistry, we have also conducted carefully designed biogeochemical experiments for more contaminants investigating biological and chemical dissolution, (bio)sorption, (bio)precipitation, desorption and redox reactions. Especially, the interactions between iron oxides and environmentally significant pollutants including U(VI, IV), Tc(VII, IV) have carefully studied focusing on their speciation, sorption, redox chemistry and mobility.