He received the doctorate degree in biogeochemistry from Hebrew University of Jerusalem, Israel, in 1998. Han has established a graduate/undergraduate training and research program in environmental chemistry, biogeochemistry and a new radiochemistry program. He won the JSU 2016 HEADWAE Award from the Mississippi State Legislature and was named Outstanding Scientific Division Chair, Mississippi Academy of Science, 2016. Han has published one book, 90 refereed journal papers and holds a U.S. provisional patent (Google Scholar H 31). He serves on the editorial boards of Water, Air and Soil Pollution and Soil and Sediment Contamination. He is editor-in-chief of the Journal of Bioremediation and Biodegradation.